diff options
Diffstat (limited to 'kernel/tools/testing/selftests/x86')
16 files changed, 2652 insertions, 15 deletions
diff --git a/kernel/tools/testing/selftests/x86/Makefile b/kernel/tools/testing/selftests/x86/Makefile index 9b0d8baf2..eabcff411 100644 --- a/kernel/tools/testing/selftests/x86/Makefile +++ b/kernel/tools/testing/selftests/x86/Makefile @@ -4,8 +4,9 @@ include ../lib.mk .PHONY: all all_32 all_64 warn_32bit_failure clean -TARGETS_C_BOTHBITS := sigreturn single_step_syscall -TARGETS_C_32BIT_ONLY := entry_from_vm86 +TARGETS_C_BOTHBITS := single_step_syscall sysret_ss_attrs ldt_gdt syscall_nt ptrace_syscall +TARGETS_C_32BIT_ONLY := entry_from_vm86 syscall_arg_fault sigreturn test_syscall_vdso unwind_vdso \ + test_FCMOV test_FCOMI test_FISTTP TARGETS_C_32BIT_ALL := $(TARGETS_C_BOTHBITS) $(TARGETS_C_32BIT_ONLY) BINARIES_32 := $(TARGETS_C_32BIT_ALL:%=%_32) @@ -35,7 +36,7 @@ clean: $(RM) $(BINARIES_32) $(BINARIES_64) $(TARGETS_C_32BIT_ALL:%=%_32): %_32: %.c - $(CC) -m32 -o $@ $(CFLAGS) $(EXTRA_CFLAGS) $^ -lrt -ldl + $(CC) -m32 -o $@ $(CFLAGS) $(EXTRA_CFLAGS) $^ -lrt -ldl -lm $(TARGETS_C_BOTHBITS:%=%_64): %_64: %.c $(CC) -m64 -o $@ $(CFLAGS) $(EXTRA_CFLAGS) $^ -lrt -ldl @@ -57,3 +58,8 @@ warn_32bit_failure: echo " yum install glibc-devel.*i686"; \ exit 0; endif + +# Some tests have additional dependencies. +sysret_ss_attrs_64: thunks.S +ptrace_syscall_32: raw_syscall_helper_32.S +test_syscall_vdso_32: thunks_32.S diff --git a/kernel/tools/testing/selftests/x86/entry_from_vm86.c b/kernel/tools/testing/selftests/x86/entry_from_vm86.c index 5c38a1876..d075ea0e5 100644 --- a/kernel/tools/testing/selftests/x86/entry_from_vm86.c +++ b/kernel/tools/testing/selftests/x86/entry_from_vm86.c @@ -28,6 +28,55 @@ static unsigned long load_addr = 0x10000; static int nerrs = 0; +static void sethandler(int sig, void (*handler)(int, siginfo_t *, void *), + int flags) +{ + struct sigaction sa; + memset(&sa, 0, sizeof(sa)); + sa.sa_sigaction = handler; + sa.sa_flags = SA_SIGINFO | flags; + sigemptyset(&sa.sa_mask); + if (sigaction(sig, &sa, 0)) + err(1, "sigaction"); +} + +static void clearhandler(int sig) +{ + struct sigaction sa; + memset(&sa, 0, sizeof(sa)); + sa.sa_handler = SIG_DFL; + sigemptyset(&sa.sa_mask); + if (sigaction(sig, &sa, 0)) + err(1, "sigaction"); +} + +static sig_atomic_t got_signal; + +static void sighandler(int sig, siginfo_t *info, void *ctx_void) +{ + ucontext_t *ctx = (ucontext_t*)ctx_void; + + if (ctx->uc_mcontext.gregs[REG_EFL] & X86_EFLAGS_VM || + (ctx->uc_mcontext.gregs[REG_CS] & 3) != 3) { + printf("[FAIL]\tSignal frame should not reflect vm86 mode\n"); + nerrs++; + } + + const char *signame; + if (sig == SIGSEGV) + signame = "SIGSEGV"; + else if (sig == SIGILL) + signame = "SIGILL"; + else + signame = "unexpected signal"; + + printf("[INFO]\t%s: FLAGS = 0x%lx, CS = 0x%hx\n", signame, + (unsigned long)ctx->uc_mcontext.gregs[REG_EFL], + (unsigned short)ctx->uc_mcontext.gregs[REG_CS]); + + got_signal = 1; +} + asm ( ".pushsection .rodata\n\t" ".type vmcode_bound, @object\n\t" @@ -38,6 +87,14 @@ asm ( "int3\n\t" "vmcode_sysenter:\n\t" "sysenter\n\t" + "vmcode_syscall:\n\t" + "syscall\n\t" + "vmcode_sti:\n\t" + "sti\n\t" + "vmcode_int3:\n\t" + "int3\n\t" + "vmcode_int80:\n\t" + "int $0x80\n\t" ".size vmcode, . - vmcode\n\t" "end_vmcode:\n\t" ".code32\n\t" @@ -45,9 +102,12 @@ asm ( ); extern unsigned char vmcode[], end_vmcode[]; -extern unsigned char vmcode_bound[], vmcode_sysenter[]; +extern unsigned char vmcode_bound[], vmcode_sysenter[], vmcode_syscall[], + vmcode_sti[], vmcode_int3[], vmcode_int80[]; -static void do_test(struct vm86plus_struct *v86, unsigned long eip, +/* Returns false if the test was skipped. */ +static bool do_test(struct vm86plus_struct *v86, unsigned long eip, + unsigned int rettype, unsigned int retarg, const char *text) { long ret; @@ -56,9 +116,10 @@ static void do_test(struct vm86plus_struct *v86, unsigned long eip, v86->regs.eip = eip; ret = vm86(VM86_ENTER, v86); - if (ret == -1 && errno == ENOSYS) { - printf("[SKIP]\tvm86 not supported\n"); - return; + if (ret == -1 && (errno == ENOSYS || errno == EPERM)) { + printf("[SKIP]\tvm86 %s\n", + errno == ENOSYS ? "not supported" : "not allowed"); + return false; } if (VM86_TYPE(ret) == VM86_INTx) { @@ -73,13 +134,30 @@ static void do_test(struct vm86plus_struct *v86, unsigned long eip, else sprintf(trapname, "%d", trapno); - printf("[OK]\tExited vm86 mode due to #%s\n", trapname); + printf("[INFO]\tExited vm86 mode due to #%s\n", trapname); } else if (VM86_TYPE(ret) == VM86_UNKNOWN) { - printf("[OK]\tExited vm86 mode due to unhandled GP fault\n"); + printf("[INFO]\tExited vm86 mode due to unhandled GP fault\n"); + } else if (VM86_TYPE(ret) == VM86_TRAP) { + printf("[INFO]\tExited vm86 mode due to a trap (arg=%ld)\n", + VM86_ARG(ret)); + } else if (VM86_TYPE(ret) == VM86_SIGNAL) { + printf("[INFO]\tExited vm86 mode due to a signal\n"); + } else if (VM86_TYPE(ret) == VM86_STI) { + printf("[INFO]\tExited vm86 mode due to STI\n"); } else { - printf("[OK]\tExited vm86 mode due to type %ld, arg %ld\n", + printf("[INFO]\tExited vm86 mode due to type %ld, arg %ld\n", VM86_TYPE(ret), VM86_ARG(ret)); } + + if (rettype == -1 || + (VM86_TYPE(ret) == rettype && VM86_ARG(ret) == retarg)) { + printf("[OK]\tReturned correctly\n"); + } else { + printf("[FAIL]\tIncorrect return reason\n"); + nerrs++; + } + + return true; } int main(void) @@ -105,10 +183,56 @@ int main(void) assert((v86.regs.cs & 3) == 0); /* Looks like RPL = 0 */ /* #BR -- should deliver SIG??? */ - do_test(&v86, vmcode_bound - vmcode, "#BR"); + do_test(&v86, vmcode_bound - vmcode, VM86_INTx, 5, "#BR"); + + /* + * SYSENTER -- should cause #GP or #UD depending on CPU. + * Expected return type -1 means that we shouldn't validate + * the vm86 return value. This will avoid problems on non-SEP + * CPUs. + */ + sethandler(SIGILL, sighandler, 0); + do_test(&v86, vmcode_sysenter - vmcode, -1, 0, "SYSENTER"); + clearhandler(SIGILL); + + /* + * SYSCALL would be a disaster in VM86 mode. Fortunately, + * there is no kernel that both enables SYSCALL and sets + * EFER.SCE, so it's #UD on all systems. But vm86 is + * buggy (or has a "feature"), so the SIGILL will actually + * be delivered. + */ + sethandler(SIGILL, sighandler, 0); + do_test(&v86, vmcode_syscall - vmcode, VM86_SIGNAL, 0, "SYSCALL"); + clearhandler(SIGILL); + + /* STI with VIP set */ + v86.regs.eflags |= X86_EFLAGS_VIP; + v86.regs.eflags &= ~X86_EFLAGS_IF; + do_test(&v86, vmcode_sti - vmcode, VM86_STI, 0, "STI with VIP set"); + + /* INT3 -- should cause #BP */ + do_test(&v86, vmcode_int3 - vmcode, VM86_TRAP, 3, "INT3"); + + /* INT80 -- should exit with "INTx 0x80" */ + v86.regs.eax = (unsigned int)-1; + do_test(&v86, vmcode_int80 - vmcode, VM86_INTx, 0x80, "int80"); + + /* Execute a null pointer */ + v86.regs.cs = 0; + v86.regs.ss = 0; + sethandler(SIGSEGV, sighandler, 0); + got_signal = 0; + if (do_test(&v86, 0, VM86_SIGNAL, 0, "Execute null pointer") && + !got_signal) { + printf("[FAIL]\tDid not receive SIGSEGV\n"); + nerrs++; + } + clearhandler(SIGSEGV); - /* SYSENTER -- should cause #GP or #UD depending on CPU */ - do_test(&v86, vmcode_sysenter - vmcode, "SYSENTER"); + /* Make sure nothing explodes if we fork. */ + if (fork() > 0) + return 0; return (nerrs == 0 ? 0 : 1); } diff --git a/kernel/tools/testing/selftests/x86/ldt_gdt.c b/kernel/tools/testing/selftests/x86/ldt_gdt.c new file mode 100644 index 000000000..31a3035cd --- /dev/null +++ b/kernel/tools/testing/selftests/x86/ldt_gdt.c @@ -0,0 +1,576 @@ +/* + * ldt_gdt.c - Test cases for LDT and GDT access + * Copyright (c) 2015 Andrew Lutomirski + */ + +#define _GNU_SOURCE +#include <err.h> +#include <stdio.h> +#include <stdint.h> +#include <signal.h> +#include <setjmp.h> +#include <stdlib.h> +#include <string.h> +#include <errno.h> +#include <unistd.h> +#include <sys/syscall.h> +#include <asm/ldt.h> +#include <sys/types.h> +#include <sys/wait.h> +#include <stdbool.h> +#include <pthread.h> +#include <sched.h> +#include <linux/futex.h> + +#define AR_ACCESSED (1<<8) + +#define AR_TYPE_RODATA (0 * (1<<9)) +#define AR_TYPE_RWDATA (1 * (1<<9)) +#define AR_TYPE_RODATA_EXPDOWN (2 * (1<<9)) +#define AR_TYPE_RWDATA_EXPDOWN (3 * (1<<9)) +#define AR_TYPE_XOCODE (4 * (1<<9)) +#define AR_TYPE_XRCODE (5 * (1<<9)) +#define AR_TYPE_XOCODE_CONF (6 * (1<<9)) +#define AR_TYPE_XRCODE_CONF (7 * (1<<9)) + +#define AR_DPL3 (3 * (1<<13)) + +#define AR_S (1 << 12) +#define AR_P (1 << 15) +#define AR_AVL (1 << 20) +#define AR_L (1 << 21) +#define AR_DB (1 << 22) +#define AR_G (1 << 23) + +static int nerrs; + +static void check_invalid_segment(uint16_t index, int ldt) +{ + uint32_t has_limit = 0, has_ar = 0, limit, ar; + uint32_t selector = (index << 3) | (ldt << 2) | 3; + + asm ("lsl %[selector], %[limit]\n\t" + "jnz 1f\n\t" + "movl $1, %[has_limit]\n\t" + "1:" + : [limit] "=r" (limit), [has_limit] "+rm" (has_limit) + : [selector] "r" (selector)); + asm ("larl %[selector], %[ar]\n\t" + "jnz 1f\n\t" + "movl $1, %[has_ar]\n\t" + "1:" + : [ar] "=r" (ar), [has_ar] "+rm" (has_ar) + : [selector] "r" (selector)); + + if (has_limit || has_ar) { + printf("[FAIL]\t%s entry %hu is valid but should be invalid\n", + (ldt ? "LDT" : "GDT"), index); + nerrs++; + } else { + printf("[OK]\t%s entry %hu is invalid\n", + (ldt ? "LDT" : "GDT"), index); + } +} + +static void check_valid_segment(uint16_t index, int ldt, + uint32_t expected_ar, uint32_t expected_limit, + bool verbose) +{ + uint32_t has_limit = 0, has_ar = 0, limit, ar; + uint32_t selector = (index << 3) | (ldt << 2) | 3; + + asm ("lsl %[selector], %[limit]\n\t" + "jnz 1f\n\t" + "movl $1, %[has_limit]\n\t" + "1:" + : [limit] "=r" (limit), [has_limit] "+rm" (has_limit) + : [selector] "r" (selector)); + asm ("larl %[selector], %[ar]\n\t" + "jnz 1f\n\t" + "movl $1, %[has_ar]\n\t" + "1:" + : [ar] "=r" (ar), [has_ar] "+rm" (has_ar) + : [selector] "r" (selector)); + + if (!has_limit || !has_ar) { + printf("[FAIL]\t%s entry %hu is invalid but should be valid\n", + (ldt ? "LDT" : "GDT"), index); + nerrs++; + return; + } + + if (ar != expected_ar) { + printf("[FAIL]\t%s entry %hu has AR 0x%08X but expected 0x%08X\n", + (ldt ? "LDT" : "GDT"), index, ar, expected_ar); + nerrs++; + } else if (limit != expected_limit) { + printf("[FAIL]\t%s entry %hu has limit 0x%08X but expected 0x%08X\n", + (ldt ? "LDT" : "GDT"), index, limit, expected_limit); + nerrs++; + } else if (verbose) { + printf("[OK]\t%s entry %hu has AR 0x%08X and limit 0x%08X\n", + (ldt ? "LDT" : "GDT"), index, ar, limit); + } +} + +static bool install_valid_mode(const struct user_desc *desc, uint32_t ar, + bool oldmode) +{ + int ret = syscall(SYS_modify_ldt, oldmode ? 1 : 0x11, + desc, sizeof(*desc)); + if (ret < -1) + errno = -ret; + if (ret == 0) { + uint32_t limit = desc->limit; + if (desc->limit_in_pages) + limit = (limit << 12) + 4095; + check_valid_segment(desc->entry_number, 1, ar, limit, true); + return true; + } else if (errno == ENOSYS) { + printf("[OK]\tmodify_ldt returned -ENOSYS\n"); + return false; + } else { + if (desc->seg_32bit) { + printf("[FAIL]\tUnexpected modify_ldt failure %d\n", + errno); + nerrs++; + return false; + } else { + printf("[OK]\tmodify_ldt rejected 16 bit segment\n"); + return false; + } + } +} + +static bool install_valid(const struct user_desc *desc, uint32_t ar) +{ + return install_valid_mode(desc, ar, false); +} + +static void install_invalid(const struct user_desc *desc, bool oldmode) +{ + int ret = syscall(SYS_modify_ldt, oldmode ? 1 : 0x11, + desc, sizeof(*desc)); + if (ret < -1) + errno = -ret; + if (ret == 0) { + check_invalid_segment(desc->entry_number, 1); + } else if (errno == ENOSYS) { + printf("[OK]\tmodify_ldt returned -ENOSYS\n"); + } else { + if (desc->seg_32bit) { + printf("[FAIL]\tUnexpected modify_ldt failure %d\n", + errno); + nerrs++; + } else { + printf("[OK]\tmodify_ldt rejected 16 bit segment\n"); + } + } +} + +static int safe_modify_ldt(int func, struct user_desc *ptr, + unsigned long bytecount) +{ + int ret = syscall(SYS_modify_ldt, 0x11, ptr, bytecount); + if (ret < -1) + errno = -ret; + return ret; +} + +static void fail_install(struct user_desc *desc) +{ + if (safe_modify_ldt(0x11, desc, sizeof(*desc)) == 0) { + printf("[FAIL]\tmodify_ldt accepted a bad descriptor\n"); + nerrs++; + } else if (errno == ENOSYS) { + printf("[OK]\tmodify_ldt returned -ENOSYS\n"); + } else { + printf("[OK]\tmodify_ldt failure %d\n", errno); + } +} + +static void do_simple_tests(void) +{ + struct user_desc desc = { + .entry_number = 0, + .base_addr = 0, + .limit = 10, + .seg_32bit = 1, + .contents = 2, /* Code, not conforming */ + .read_exec_only = 0, + .limit_in_pages = 0, + .seg_not_present = 0, + .useable = 0 + }; + install_valid(&desc, AR_DPL3 | AR_TYPE_XRCODE | AR_S | AR_P | AR_DB); + + desc.limit_in_pages = 1; + install_valid(&desc, AR_DPL3 | AR_TYPE_XRCODE | + AR_S | AR_P | AR_DB | AR_G); + + check_invalid_segment(1, 1); + + desc.entry_number = 2; + install_valid(&desc, AR_DPL3 | AR_TYPE_XRCODE | + AR_S | AR_P | AR_DB | AR_G); + + check_invalid_segment(1, 1); + + desc.base_addr = 0xf0000000; + install_valid(&desc, AR_DPL3 | AR_TYPE_XRCODE | + AR_S | AR_P | AR_DB | AR_G); + + desc.useable = 1; + install_valid(&desc, AR_DPL3 | AR_TYPE_XRCODE | + AR_S | AR_P | AR_DB | AR_G | AR_AVL); + + desc.seg_not_present = 1; + install_valid(&desc, AR_DPL3 | AR_TYPE_XRCODE | + AR_S | AR_DB | AR_G | AR_AVL); + + desc.seg_32bit = 0; + install_valid(&desc, AR_DPL3 | AR_TYPE_XRCODE | + AR_S | AR_G | AR_AVL); + + desc.seg_32bit = 1; + desc.contents = 0; + install_valid(&desc, AR_DPL3 | AR_TYPE_RWDATA | + AR_S | AR_DB | AR_G | AR_AVL); + + desc.read_exec_only = 1; + install_valid(&desc, AR_DPL3 | AR_TYPE_RODATA | + AR_S | AR_DB | AR_G | AR_AVL); + + desc.contents = 1; + install_valid(&desc, AR_DPL3 | AR_TYPE_RODATA_EXPDOWN | + AR_S | AR_DB | AR_G | AR_AVL); + + desc.read_exec_only = 0; + desc.limit_in_pages = 0; + install_valid(&desc, AR_DPL3 | AR_TYPE_RWDATA_EXPDOWN | + AR_S | AR_DB | AR_AVL); + + desc.contents = 3; + install_valid(&desc, AR_DPL3 | AR_TYPE_XRCODE_CONF | + AR_S | AR_DB | AR_AVL); + + desc.read_exec_only = 1; + install_valid(&desc, AR_DPL3 | AR_TYPE_XOCODE_CONF | + AR_S | AR_DB | AR_AVL); + + desc.read_exec_only = 0; + desc.contents = 2; + install_valid(&desc, AR_DPL3 | AR_TYPE_XRCODE | + AR_S | AR_DB | AR_AVL); + + desc.read_exec_only = 1; + +#ifdef __x86_64__ + desc.lm = 1; + install_valid(&desc, AR_DPL3 | AR_TYPE_XOCODE | + AR_S | AR_DB | AR_AVL); + desc.lm = 0; +#endif + + bool entry1_okay = install_valid(&desc, AR_DPL3 | AR_TYPE_XOCODE | + AR_S | AR_DB | AR_AVL); + + if (entry1_okay) { + printf("[RUN]\tTest fork\n"); + pid_t child = fork(); + if (child == 0) { + nerrs = 0; + check_valid_segment(desc.entry_number, 1, + AR_DPL3 | AR_TYPE_XOCODE | + AR_S | AR_DB | AR_AVL, desc.limit, + true); + check_invalid_segment(1, 1); + exit(nerrs ? 1 : 0); + } else { + int status; + if (waitpid(child, &status, 0) != child || + !WIFEXITED(status)) { + printf("[FAIL]\tChild died\n"); + nerrs++; + } else if (WEXITSTATUS(status) != 0) { + printf("[FAIL]\tChild failed\n"); + nerrs++; + } else { + printf("[OK]\tChild succeeded\n"); + } + } + + printf("[RUN]\tTest size\n"); + int i; + for (i = 0; i < 8192; i++) { + desc.entry_number = i; + desc.limit = i; + if (safe_modify_ldt(0x11, &desc, sizeof(desc)) != 0) { + printf("[FAIL]\tFailed to install entry %d\n", i); + nerrs++; + break; + } + } + for (int j = 0; j < i; j++) { + check_valid_segment(j, 1, AR_DPL3 | AR_TYPE_XOCODE | + AR_S | AR_DB | AR_AVL, j, false); + } + printf("[DONE]\tSize test\n"); + } else { + printf("[SKIP]\tSkipping fork and size tests because we have no LDT\n"); + } + + /* Test entry_number too high. */ + desc.entry_number = 8192; + fail_install(&desc); + + /* Test deletion and actions mistakeable for deletion. */ + memset(&desc, 0, sizeof(desc)); + install_valid(&desc, AR_DPL3 | AR_TYPE_RWDATA | AR_S | AR_P); + + desc.seg_not_present = 1; + install_valid(&desc, AR_DPL3 | AR_TYPE_RWDATA | AR_S); + + desc.seg_not_present = 0; + desc.read_exec_only = 1; + install_valid(&desc, AR_DPL3 | AR_TYPE_RODATA | AR_S | AR_P); + + desc.read_exec_only = 0; + desc.seg_not_present = 1; + install_valid(&desc, AR_DPL3 | AR_TYPE_RWDATA | AR_S); + + desc.read_exec_only = 1; + desc.limit = 1; + install_valid(&desc, AR_DPL3 | AR_TYPE_RODATA | AR_S); + + desc.limit = 0; + desc.base_addr = 1; + install_valid(&desc, AR_DPL3 | AR_TYPE_RODATA | AR_S); + + desc.base_addr = 0; + install_invalid(&desc, false); + + desc.seg_not_present = 0; + desc.read_exec_only = 0; + desc.seg_32bit = 1; + install_valid(&desc, AR_DPL3 | AR_TYPE_RWDATA | AR_S | AR_P | AR_DB); + install_invalid(&desc, true); +} + +/* + * 0: thread is idle + * 1: thread armed + * 2: thread should clear LDT entry 0 + * 3: thread should exit + */ +static volatile unsigned int ftx; + +static void *threadproc(void *ctx) +{ + cpu_set_t cpuset; + CPU_ZERO(&cpuset); + CPU_SET(1, &cpuset); + if (sched_setaffinity(0, sizeof(cpuset), &cpuset) != 0) + err(1, "sched_setaffinity to CPU 1"); /* should never fail */ + + while (1) { + syscall(SYS_futex, &ftx, FUTEX_WAIT, 0, NULL, NULL, 0); + while (ftx != 2) { + if (ftx >= 3) + return NULL; + } + + /* clear LDT entry 0 */ + const struct user_desc desc = {}; + if (syscall(SYS_modify_ldt, 1, &desc, sizeof(desc)) != 0) + err(1, "modify_ldt"); + + /* If ftx == 2, set it to zero. If ftx == 100, quit. */ + unsigned int x = -2; + asm volatile ("lock xaddl %[x], %[ftx]" : + [x] "+r" (x), [ftx] "+m" (ftx)); + if (x != 2) + return NULL; + } +} + +static void sethandler(int sig, void (*handler)(int, siginfo_t *, void *), + int flags) +{ + struct sigaction sa; + memset(&sa, 0, sizeof(sa)); + sa.sa_sigaction = handler; + sa.sa_flags = SA_SIGINFO | flags; + sigemptyset(&sa.sa_mask); + if (sigaction(sig, &sa, 0)) + err(1, "sigaction"); + +} + +static jmp_buf jmpbuf; + +static void sigsegv(int sig, siginfo_t *info, void *ctx_void) +{ + siglongjmp(jmpbuf, 1); +} + +static void do_multicpu_tests(void) +{ + cpu_set_t cpuset; + pthread_t thread; + int failures = 0, iters = 5, i; + unsigned short orig_ss; + + CPU_ZERO(&cpuset); + CPU_SET(1, &cpuset); + if (sched_setaffinity(0, sizeof(cpuset), &cpuset) != 0) { + printf("[SKIP]\tCannot set affinity to CPU 1\n"); + return; + } + + CPU_ZERO(&cpuset); + CPU_SET(0, &cpuset); + if (sched_setaffinity(0, sizeof(cpuset), &cpuset) != 0) { + printf("[SKIP]\tCannot set affinity to CPU 0\n"); + return; + } + + sethandler(SIGSEGV, sigsegv, 0); +#ifdef __i386__ + /* True 32-bit kernels send SIGILL instead of SIGSEGV on IRET faults. */ + sethandler(SIGILL, sigsegv, 0); +#endif + + printf("[RUN]\tCross-CPU LDT invalidation\n"); + + if (pthread_create(&thread, 0, threadproc, 0) != 0) + err(1, "pthread_create"); + + asm volatile ("mov %%ss, %0" : "=rm" (orig_ss)); + + for (i = 0; i < 5; i++) { + if (sigsetjmp(jmpbuf, 1) != 0) + continue; + + /* Make sure the thread is ready after the last test. */ + while (ftx != 0) + ; + + struct user_desc desc = { + .entry_number = 0, + .base_addr = 0, + .limit = 0xfffff, + .seg_32bit = 1, + .contents = 0, /* Data */ + .read_exec_only = 0, + .limit_in_pages = 1, + .seg_not_present = 0, + .useable = 0 + }; + + if (safe_modify_ldt(0x11, &desc, sizeof(desc)) != 0) { + if (errno != ENOSYS) + err(1, "modify_ldt"); + printf("[SKIP]\tmodify_ldt unavailable\n"); + break; + } + + /* Arm the thread. */ + ftx = 1; + syscall(SYS_futex, &ftx, FUTEX_WAKE, 0, NULL, NULL, 0); + + asm volatile ("mov %0, %%ss" : : "r" (0x7)); + + /* Go! */ + ftx = 2; + + while (ftx != 0) + ; + + /* + * On success, modify_ldt will segfault us synchronously, + * and we'll escape via siglongjmp. + */ + + failures++; + asm volatile ("mov %0, %%ss" : : "rm" (orig_ss)); + }; + + ftx = 100; /* Kill the thread. */ + syscall(SYS_futex, &ftx, FUTEX_WAKE, 0, NULL, NULL, 0); + + if (pthread_join(thread, NULL) != 0) + err(1, "pthread_join"); + + if (failures) { + printf("[FAIL]\t%d of %d iterations failed\n", failures, iters); + nerrs++; + } else { + printf("[OK]\tAll %d iterations succeeded\n", iters); + } +} + +static int finish_exec_test(void) +{ + /* + * In a sensible world, this would be check_invalid_segment(0, 1); + * For better or for worse, though, the LDT is inherited across exec. + * We can probably change this safely, but for now we test it. + */ + check_valid_segment(0, 1, + AR_DPL3 | AR_TYPE_XRCODE | AR_S | AR_P | AR_DB, + 42, true); + + return nerrs ? 1 : 0; +} + +static void do_exec_test(void) +{ + printf("[RUN]\tTest exec\n"); + + struct user_desc desc = { + .entry_number = 0, + .base_addr = 0, + .limit = 42, + .seg_32bit = 1, + .contents = 2, /* Code, not conforming */ + .read_exec_only = 0, + .limit_in_pages = 0, + .seg_not_present = 0, + .useable = 0 + }; + install_valid(&desc, AR_DPL3 | AR_TYPE_XRCODE | AR_S | AR_P | AR_DB); + + pid_t child = fork(); + if (child == 0) { + execl("/proc/self/exe", "ldt_gdt_test_exec", NULL); + printf("[FAIL]\tCould not exec self\n"); + exit(1); /* exec failed */ + } else { + int status; + if (waitpid(child, &status, 0) != child || + !WIFEXITED(status)) { + printf("[FAIL]\tChild died\n"); + nerrs++; + } else if (WEXITSTATUS(status) != 0) { + printf("[FAIL]\tChild failed\n"); + nerrs++; + } else { + printf("[OK]\tChild succeeded\n"); + } + } +} + +int main(int argc, char **argv) +{ + if (argc == 1 && !strcmp(argv[0], "ldt_gdt_test_exec")) + return finish_exec_test(); + + do_simple_tests(); + + do_multicpu_tests(); + + do_exec_test(); + + return nerrs ? 1 : 0; +} diff --git a/kernel/tools/testing/selftests/x86/ptrace_syscall.c b/kernel/tools/testing/selftests/x86/ptrace_syscall.c new file mode 100644 index 000000000..5105b49cd --- /dev/null +++ b/kernel/tools/testing/selftests/x86/ptrace_syscall.c @@ -0,0 +1,294 @@ +#define _GNU_SOURCE + +#include <sys/ptrace.h> +#include <sys/types.h> +#include <sys/wait.h> +#include <sys/syscall.h> +#include <sys/user.h> +#include <unistd.h> +#include <errno.h> +#include <stddef.h> +#include <stdio.h> +#include <err.h> +#include <string.h> +#include <asm/ptrace-abi.h> +#include <sys/auxv.h> + +/* Bitness-agnostic defines for user_regs_struct fields. */ +#ifdef __x86_64__ +# define user_syscall_nr orig_rax +# define user_arg0 rdi +# define user_arg1 rsi +# define user_arg2 rdx +# define user_arg3 r10 +# define user_arg4 r8 +# define user_arg5 r9 +# define user_ip rip +# define user_ax rax +#else +# define user_syscall_nr orig_eax +# define user_arg0 ebx +# define user_arg1 ecx +# define user_arg2 edx +# define user_arg3 esi +# define user_arg4 edi +# define user_arg5 ebp +# define user_ip eip +# define user_ax eax +#endif + +static int nerrs = 0; + +struct syscall_args32 { + uint32_t nr, arg0, arg1, arg2, arg3, arg4, arg5; +}; + +#ifdef __i386__ +extern void sys32_helper(struct syscall_args32 *, void *); +extern void int80_and_ret(void); +#endif + +/* + * Helper to invoke int80 with controlled regs and capture the final regs. + */ +static void do_full_int80(struct syscall_args32 *args) +{ +#ifdef __x86_64__ + register unsigned long bp asm("bp") = args->arg5; + asm volatile ("int $0x80" + : "+a" (args->nr), + "+b" (args->arg0), "+c" (args->arg1), "+d" (args->arg2), + "+S" (args->arg3), "+D" (args->arg4), "+r" (bp)); + args->arg5 = bp; +#else + sys32_helper(args, int80_and_ret); +#endif +} + +#ifdef __i386__ +static void (*vsyscall32)(void); + +/* + * Nasty helper to invoke AT_SYSINFO (i.e. __kernel_vsyscall) with + * controlled regs and capture the final regs. This is so nasty that it + * crashes my copy of gdb :) + */ +static void do_full_vsyscall32(struct syscall_args32 *args) +{ + sys32_helper(args, vsyscall32); +} +#endif + +static siginfo_t wait_trap(pid_t chld) +{ + siginfo_t si; + if (waitid(P_PID, chld, &si, WEXITED|WSTOPPED) != 0) + err(1, "waitid"); + if (si.si_pid != chld) + errx(1, "got unexpected pid in event\n"); + if (si.si_code != CLD_TRAPPED) + errx(1, "got unexpected event type %d\n", si.si_code); + return si; +} + +static void sethandler(int sig, void (*handler)(int, siginfo_t *, void *), + int flags) +{ + struct sigaction sa; + memset(&sa, 0, sizeof(sa)); + sa.sa_sigaction = handler; + sa.sa_flags = SA_SIGINFO | flags; + sigemptyset(&sa.sa_mask); + if (sigaction(sig, &sa, 0)) + err(1, "sigaction"); +} + +static void clearhandler(int sig) +{ + struct sigaction sa; + memset(&sa, 0, sizeof(sa)); + sa.sa_handler = SIG_DFL; + sigemptyset(&sa.sa_mask); + if (sigaction(sig, &sa, 0)) + err(1, "sigaction"); +} + +#ifdef __x86_64__ +# define REG_BP REG_RBP +#else +# define REG_BP REG_EBP +#endif + +static void empty_handler(int sig, siginfo_t *si, void *ctx_void) +{ +} + +static void test_sys32_regs(void (*do_syscall)(struct syscall_args32 *)) +{ + struct syscall_args32 args = { + .nr = 224, /* gettid */ + .arg0 = 10, .arg1 = 11, .arg2 = 12, + .arg3 = 13, .arg4 = 14, .arg5 = 15, + }; + + do_syscall(&args); + + if (args.nr != getpid() || + args.arg0 != 10 || args.arg1 != 11 || args.arg2 != 12 || + args.arg3 != 13 || args.arg4 != 14 || args.arg5 != 15) { + printf("[FAIL]\tgetpid() failed to preseve regs\n"); + nerrs++; + } else { + printf("[OK]\tgetpid() preserves regs\n"); + } + + sethandler(SIGUSR1, empty_handler, 0); + + args.nr = 37; /* kill */ + args.arg0 = getpid(); + args.arg1 = SIGUSR1; + do_syscall(&args); + if (args.nr != 0 || + args.arg0 != getpid() || args.arg1 != SIGUSR1 || args.arg2 != 12 || + args.arg3 != 13 || args.arg4 != 14 || args.arg5 != 15) { + printf("[FAIL]\tkill(getpid(), SIGUSR1) failed to preseve regs\n"); + nerrs++; + } else { + printf("[OK]\tkill(getpid(), SIGUSR1) preserves regs\n"); + } + clearhandler(SIGUSR1); +} + +static void test_ptrace_syscall_restart(void) +{ + printf("[RUN]\tptrace-induced syscall restart\n"); + pid_t chld = fork(); + if (chld < 0) + err(1, "fork"); + + if (chld == 0) { + if (ptrace(PTRACE_TRACEME, 0, 0, 0) != 0) + err(1, "PTRACE_TRACEME"); + + printf("\tChild will make one syscall\n"); + raise(SIGSTOP); + + syscall(SYS_gettid, 10, 11, 12, 13, 14, 15); + _exit(0); + } + + int status; + + /* Wait for SIGSTOP. */ + if (waitpid(chld, &status, 0) != chld || !WIFSTOPPED(status)) + err(1, "waitpid"); + + struct user_regs_struct regs; + + printf("[RUN]\tSYSEMU\n"); + if (ptrace(PTRACE_SYSEMU, chld, 0, 0) != 0) + err(1, "PTRACE_SYSCALL"); + wait_trap(chld); + + if (ptrace(PTRACE_GETREGS, chld, 0, ®s) != 0) + err(1, "PTRACE_GETREGS"); + + if (regs.user_syscall_nr != SYS_gettid || + regs.user_arg0 != 10 || regs.user_arg1 != 11 || + regs.user_arg2 != 12 || regs.user_arg3 != 13 || + regs.user_arg4 != 14 || regs.user_arg5 != 15) { + printf("[FAIL]\tInitial args are wrong (nr=%lu, args=%lu %lu %lu %lu %lu %lu)\n", (unsigned long)regs.user_syscall_nr, (unsigned long)regs.user_arg0, (unsigned long)regs.user_arg1, (unsigned long)regs.user_arg2, (unsigned long)regs.user_arg3, (unsigned long)regs.user_arg4, (unsigned long)regs.user_arg5); + nerrs++; + } else { + printf("[OK]\tInitial nr and args are correct\n"); + } + + printf("[RUN]\tRestart the syscall (ip = 0x%lx)\n", + (unsigned long)regs.user_ip); + + /* + * This does exactly what it appears to do if syscall is int80 or + * SYSCALL64. For SYSCALL32 or SYSENTER, though, this is highly + * magical. It needs to work so that ptrace and syscall restart + * work as expected. + */ + regs.user_ax = regs.user_syscall_nr; + regs.user_ip -= 2; + if (ptrace(PTRACE_SETREGS, chld, 0, ®s) != 0) + err(1, "PTRACE_SETREGS"); + + if (ptrace(PTRACE_SYSEMU, chld, 0, 0) != 0) + err(1, "PTRACE_SYSCALL"); + wait_trap(chld); + + if (ptrace(PTRACE_GETREGS, chld, 0, ®s) != 0) + err(1, "PTRACE_GETREGS"); + + if (regs.user_syscall_nr != SYS_gettid || + regs.user_arg0 != 10 || regs.user_arg1 != 11 || + regs.user_arg2 != 12 || regs.user_arg3 != 13 || + regs.user_arg4 != 14 || regs.user_arg5 != 15) { + printf("[FAIL]\tRestart nr or args are wrong (nr=%lu, args=%lu %lu %lu %lu %lu %lu)\n", (unsigned long)regs.user_syscall_nr, (unsigned long)regs.user_arg0, (unsigned long)regs.user_arg1, (unsigned long)regs.user_arg2, (unsigned long)regs.user_arg3, (unsigned long)regs.user_arg4, (unsigned long)regs.user_arg5); + nerrs++; + } else { + printf("[OK]\tRestarted nr and args are correct\n"); + } + + printf("[RUN]\tChange nr and args and restart the syscall (ip = 0x%lx)\n", + (unsigned long)regs.user_ip); + + regs.user_ax = SYS_getpid; + regs.user_arg0 = 20; + regs.user_arg1 = 21; + regs.user_arg2 = 22; + regs.user_arg3 = 23; + regs.user_arg4 = 24; + regs.user_arg5 = 25; + regs.user_ip -= 2; + + if (ptrace(PTRACE_SETREGS, chld, 0, ®s) != 0) + err(1, "PTRACE_SETREGS"); + + if (ptrace(PTRACE_SYSEMU, chld, 0, 0) != 0) + err(1, "PTRACE_SYSCALL"); + wait_trap(chld); + + if (ptrace(PTRACE_GETREGS, chld, 0, ®s) != 0) + err(1, "PTRACE_GETREGS"); + + if (regs.user_syscall_nr != SYS_getpid || + regs.user_arg0 != 20 || regs.user_arg1 != 21 || regs.user_arg2 != 22 || + regs.user_arg3 != 23 || regs.user_arg4 != 24 || regs.user_arg5 != 25) { + printf("[FAIL]\tRestart nr or args are wrong (nr=%lu, args=%lu %lu %lu %lu %lu %lu)\n", (unsigned long)regs.user_syscall_nr, (unsigned long)regs.user_arg0, (unsigned long)regs.user_arg1, (unsigned long)regs.user_arg2, (unsigned long)regs.user_arg3, (unsigned long)regs.user_arg4, (unsigned long)regs.user_arg5); + nerrs++; + } else { + printf("[OK]\tReplacement nr and args are correct\n"); + } + + if (ptrace(PTRACE_CONT, chld, 0, 0) != 0) + err(1, "PTRACE_CONT"); + if (waitpid(chld, &status, 0) != chld) + err(1, "waitpid"); + if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) { + printf("[FAIL]\tChild failed\n"); + nerrs++; + } else { + printf("[OK]\tChild exited cleanly\n"); + } +} + +int main() +{ + printf("[RUN]\tCheck int80 return regs\n"); + test_sys32_regs(do_full_int80); + +#if defined(__i386__) && (!defined(__GLIBC__) || __GLIBC__ > 2 || __GLIBC_MINOR__ >= 16) + vsyscall32 = (void *)getauxval(AT_SYSINFO); + printf("[RUN]\tCheck AT_SYSINFO return regs\n"); + test_sys32_regs(do_full_vsyscall32); +#endif + + test_ptrace_syscall_restart(); + + return 0; +} diff --git a/kernel/tools/testing/selftests/x86/raw_syscall_helper_32.S b/kernel/tools/testing/selftests/x86/raw_syscall_helper_32.S new file mode 100644 index 000000000..534e71e35 --- /dev/null +++ b/kernel/tools/testing/selftests/x86/raw_syscall_helper_32.S @@ -0,0 +1,46 @@ +.global sys32_helper +sys32_helper: + /* Args: syscall_args_32*, function pointer */ + pushl %ebp + pushl %ebx + pushl %esi + pushl %edi + movl 5*4(%esp), %eax /* pointer to args struct */ + + movl 1*4(%eax), %ebx + movl 2*4(%eax), %ecx + movl 3*4(%eax), %edx + movl 4*4(%eax), %esi + movl 5*4(%eax), %edi + movl 6*4(%eax), %ebp + movl 0*4(%eax), %eax + + call *(6*4)(%esp) /* Do the syscall */ + + /* Now we need to recover without losing any reg values */ + pushl %eax + movl 6*4(%esp), %eax + popl 0*4(%eax) + movl %ebx, 1*4(%eax) + movl %ecx, 2*4(%eax) + movl %edx, 3*4(%eax) + movl %esi, 4*4(%eax) + movl %edi, 5*4(%eax) + movl %ebp, 6*4(%eax) + + popl %edi + popl %esi + popl %ebx + popl %ebp + ret + + .type sys32_helper, @function + .size sys32_helper, .-sys32_helper + +.global int80_and_ret +int80_and_ret: + int $0x80 + ret + + .type int80_and_ret, @function + .size int80_and_ret, .-int80_and_ret diff --git a/kernel/tools/testing/selftests/x86/syscall_arg_fault.c b/kernel/tools/testing/selftests/x86/syscall_arg_fault.c new file mode 100644 index 000000000..7db4fc9fa --- /dev/null +++ b/kernel/tools/testing/selftests/x86/syscall_arg_fault.c @@ -0,0 +1,130 @@ +/* + * syscall_arg_fault.c - tests faults 32-bit fast syscall stack args + * Copyright (c) 2015 Andrew Lutomirski + * + * This program is free software; you can redistribute it and/or modify + * it under the terms and conditions of the GNU General Public License, + * version 2, as published by the Free Software Foundation. + * + * This program is distributed in the hope it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + */ + +#define _GNU_SOURCE + +#include <stdlib.h> +#include <stdio.h> +#include <string.h> +#include <sys/signal.h> +#include <sys/ucontext.h> +#include <err.h> +#include <setjmp.h> +#include <errno.h> + +/* Our sigaltstack scratch space. */ +static unsigned char altstack_data[SIGSTKSZ]; + +static void sethandler(int sig, void (*handler)(int, siginfo_t *, void *), + int flags) +{ + struct sigaction sa; + memset(&sa, 0, sizeof(sa)); + sa.sa_sigaction = handler; + sa.sa_flags = SA_SIGINFO | flags; + sigemptyset(&sa.sa_mask); + if (sigaction(sig, &sa, 0)) + err(1, "sigaction"); +} + +static volatile sig_atomic_t sig_traps; +static sigjmp_buf jmpbuf; + +static volatile sig_atomic_t n_errs; + +static void sigsegv(int sig, siginfo_t *info, void *ctx_void) +{ + ucontext_t *ctx = (ucontext_t*)ctx_void; + + if (ctx->uc_mcontext.gregs[REG_EAX] != -EFAULT) { + printf("[FAIL]\tAX had the wrong value: 0x%x\n", + ctx->uc_mcontext.gregs[REG_EAX]); + n_errs++; + } else { + printf("[OK]\tSeems okay\n"); + } + + siglongjmp(jmpbuf, 1); +} + +static void sigill(int sig, siginfo_t *info, void *ctx_void) +{ + printf("[SKIP]\tIllegal instruction\n"); + siglongjmp(jmpbuf, 1); +} + +int main() +{ + stack_t stack = { + .ss_sp = altstack_data, + .ss_size = SIGSTKSZ, + }; + if (sigaltstack(&stack, NULL) != 0) + err(1, "sigaltstack"); + + sethandler(SIGSEGV, sigsegv, SA_ONSTACK); + sethandler(SIGILL, sigill, SA_ONSTACK); + + /* + * Exercise another nasty special case. The 32-bit SYSCALL + * and SYSENTER instructions (even in compat mode) each + * clobber one register. A Linux system call has a syscall + * number and six arguments, and the user stack pointer + * needs to live in some register on return. That means + * that we need eight registers, but SYSCALL and SYSENTER + * only preserve seven registers. As a result, one argument + * ends up on the stack. The stack is user memory, which + * means that the kernel can fail to read it. + * + * The 32-bit fast system calls don't have a defined ABI: + * we're supposed to invoke them through the vDSO. So we'll + * fudge it: we set all regs to invalid pointer values and + * invoke the entry instruction. The return will fail no + * matter what, and we completely lose our program state, + * but we can fix it up with a signal handler. + */ + + printf("[RUN]\tSYSENTER with invalid state\n"); + if (sigsetjmp(jmpbuf, 1) == 0) { + asm volatile ( + "movl $-1, %%eax\n\t" + "movl $-1, %%ebx\n\t" + "movl $-1, %%ecx\n\t" + "movl $-1, %%edx\n\t" + "movl $-1, %%esi\n\t" + "movl $-1, %%edi\n\t" + "movl $-1, %%ebp\n\t" + "movl $-1, %%esp\n\t" + "sysenter" + : : : "memory", "flags"); + } + + printf("[RUN]\tSYSCALL with invalid state\n"); + if (sigsetjmp(jmpbuf, 1) == 0) { + asm volatile ( + "movl $-1, %%eax\n\t" + "movl $-1, %%ebx\n\t" + "movl $-1, %%ecx\n\t" + "movl $-1, %%edx\n\t" + "movl $-1, %%esi\n\t" + "movl $-1, %%edi\n\t" + "movl $-1, %%ebp\n\t" + "movl $-1, %%esp\n\t" + "syscall\n\t" + "pushl $0" /* make sure we segfault cleanly */ + : : : "memory", "flags"); + } + + return 0; +} diff --git a/kernel/tools/testing/selftests/x86/syscall_nt.c b/kernel/tools/testing/selftests/x86/syscall_nt.c new file mode 100644 index 000000000..60c06af46 --- /dev/null +++ b/kernel/tools/testing/selftests/x86/syscall_nt.c @@ -0,0 +1,54 @@ +/* + * syscall_nt.c - checks syscalls with NT set + * Copyright (c) 2014-2015 Andrew Lutomirski + * + * This program is free software; you can redistribute it and/or modify + * it under the terms and conditions of the GNU General Public License, + * version 2, as published by the Free Software Foundation. + * + * This program is distributed in the hope it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * Some obscure user-space code requires the ability to make system calls + * with FLAGS.NT set. Make sure it works. + */ + +#include <stdio.h> +#include <unistd.h> +#include <sys/syscall.h> +#include <asm/processor-flags.h> + +#ifdef __x86_64__ +# define WIDTH "q" +#else +# define WIDTH "l" +#endif + +static unsigned long get_eflags(void) +{ + unsigned long eflags; + asm volatile ("pushf" WIDTH "\n\tpop" WIDTH " %0" : "=rm" (eflags)); + return eflags; +} + +static void set_eflags(unsigned long eflags) +{ + asm volatile ("push" WIDTH " %0\n\tpopf" WIDTH + : : "rm" (eflags) : "flags"); +} + +int main() +{ + printf("[RUN]\tSet NT and issue a syscall\n"); + set_eflags(get_eflags() | X86_EFLAGS_NT); + syscall(SYS_getpid); + if (get_eflags() & X86_EFLAGS_NT) { + printf("[OK]\tThe syscall worked and NT is still set\n"); + return 0; + } else { + printf("[FAIL]\tThe syscall worked but NT was cleared\n"); + return 1; + } +} diff --git a/kernel/tools/testing/selftests/x86/sysret_ss_attrs.c b/kernel/tools/testing/selftests/x86/sysret_ss_attrs.c new file mode 100644 index 000000000..ce42d5a64 --- /dev/null +++ b/kernel/tools/testing/selftests/x86/sysret_ss_attrs.c @@ -0,0 +1,112 @@ +/* + * sysret_ss_attrs.c - test that syscalls return valid hidden SS attributes + * Copyright (c) 2015 Andrew Lutomirski + * + * This program is free software; you can redistribute it and/or modify + * it under the terms and conditions of the GNU General Public License, + * version 2, as published by the Free Software Foundation. + * + * This program is distributed in the hope it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * On AMD CPUs, SYSRET can return with a valid SS descriptor with with + * the hidden attributes set to an unusable state. Make sure the kernel + * doesn't let this happen. + */ + +#define _GNU_SOURCE + +#include <stdlib.h> +#include <unistd.h> +#include <stdio.h> +#include <string.h> +#include <sys/mman.h> +#include <err.h> +#include <stddef.h> +#include <stdbool.h> +#include <pthread.h> + +static void *threadproc(void *ctx) +{ + /* + * Do our best to cause sleeps on this CPU to exit the kernel and + * re-enter with SS = 0. + */ + while (true) + ; + + return NULL; +} + +#ifdef __x86_64__ +extern unsigned long call32_from_64(void *stack, void (*function)(void)); + +asm (".pushsection .text\n\t" + ".code32\n\t" + "test_ss:\n\t" + "pushl $0\n\t" + "popl %eax\n\t" + "ret\n\t" + ".code64"); +extern void test_ss(void); +#endif + +int main() +{ + /* + * Start a busy-looping thread on the same CPU we're on. + * For simplicity, just stick everything to CPU 0. This will + * fail in some containers, but that's probably okay. + */ + cpu_set_t cpuset; + CPU_ZERO(&cpuset); + CPU_SET(0, &cpuset); + if (sched_setaffinity(0, sizeof(cpuset), &cpuset) != 0) + printf("[WARN]\tsched_setaffinity failed\n"); + + pthread_t thread; + if (pthread_create(&thread, 0, threadproc, 0) != 0) + err(1, "pthread_create"); + +#ifdef __x86_64__ + unsigned char *stack32 = mmap(NULL, 4096, PROT_READ | PROT_WRITE, + MAP_32BIT | MAP_ANONYMOUS | MAP_PRIVATE, + -1, 0); + if (stack32 == MAP_FAILED) + err(1, "mmap"); +#endif + + printf("[RUN]\tSyscalls followed by SS validation\n"); + + for (int i = 0; i < 1000; i++) { + /* + * Go to sleep and return using sysret (if we're 64-bit + * or we're 32-bit on AMD on a 64-bit kernel). On AMD CPUs, + * SYSRET doesn't fix up the cached SS descriptor, so the + * kernel needs some kind of workaround to make sure that we + * end the system call with a valid stack segment. This + * can be a confusing failure because the SS *selector* + * is the same regardless. + */ + usleep(2); + +#ifdef __x86_64__ + /* + * On 32-bit, just doing a syscall through glibc is enough + * to cause a crash if our cached SS descriptor is invalid. + * On 64-bit, it's not, so try extra hard. + */ + call32_from_64(stack32 + 4088, test_ss); +#endif + } + + printf("[OK]\tWe survived\n"); + +#ifdef __x86_64__ + munmap(stack32, 4096); +#endif + + return 0; +} diff --git a/kernel/tools/testing/selftests/x86/test_FCMOV.c b/kernel/tools/testing/selftests/x86/test_FCMOV.c new file mode 100644 index 000000000..4adcca0c8 --- /dev/null +++ b/kernel/tools/testing/selftests/x86/test_FCMOV.c @@ -0,0 +1,93 @@ +#undef _GNU_SOURCE +#define _GNU_SOURCE 1 +#undef __USE_GNU +#define __USE_GNU 1 +#include <unistd.h> +#include <stdlib.h> +#include <string.h> +#include <stdio.h> +#include <signal.h> +#include <sys/types.h> +#include <sys/select.h> +#include <sys/time.h> +#include <sys/wait.h> + +#define TEST(insn) \ +long double __attribute__((noinline)) insn(long flags) \ +{ \ + long double out; \ + asm ("\n" \ + " push %1""\n" \ + " popf""\n" \ + " fldpi""\n" \ + " fld1""\n" \ + " " #insn " %%st(1), %%st" "\n" \ + " ffree %%st(1)" "\n" \ + : "=t" (out) \ + : "r" (flags) \ + ); \ + return out; \ +} + +TEST(fcmovb) +TEST(fcmove) +TEST(fcmovbe) +TEST(fcmovu) +TEST(fcmovnb) +TEST(fcmovne) +TEST(fcmovnbe) +TEST(fcmovnu) + +enum { + CF = 1 << 0, + PF = 1 << 2, + ZF = 1 << 6, +}; + +void sighandler(int sig) +{ + printf("[FAIL]\tGot signal %d, exiting\n", sig); + exit(1); +} + +int main(int argc, char **argv, char **envp) +{ + int err = 0; + + /* SIGILL triggers on 32-bit kernels w/o fcomi emulation + * when run with "no387 nofxsr". Other signals are caught + * just in case. + */ + signal(SIGILL, sighandler); + signal(SIGFPE, sighandler); + signal(SIGSEGV, sighandler); + + printf("[RUN]\tTesting fcmovCC instructions\n"); + /* If fcmovCC() returns 1.0, the move wasn't done */ + err |= !(fcmovb(0) == 1.0); err |= !(fcmovnb(0) != 1.0); + err |= !(fcmove(0) == 1.0); err |= !(fcmovne(0) != 1.0); + err |= !(fcmovbe(0) == 1.0); err |= !(fcmovnbe(0) != 1.0); + err |= !(fcmovu(0) == 1.0); err |= !(fcmovnu(0) != 1.0); + + err |= !(fcmovb(CF) != 1.0); err |= !(fcmovnb(CF) == 1.0); + err |= !(fcmove(CF) == 1.0); err |= !(fcmovne(CF) != 1.0); + err |= !(fcmovbe(CF) != 1.0); err |= !(fcmovnbe(CF) == 1.0); + err |= !(fcmovu(CF) == 1.0); err |= !(fcmovnu(CF) != 1.0); + + err |= !(fcmovb(ZF) == 1.0); err |= !(fcmovnb(ZF) != 1.0); + err |= !(fcmove(ZF) != 1.0); err |= !(fcmovne(ZF) == 1.0); + err |= !(fcmovbe(ZF) != 1.0); err |= !(fcmovnbe(ZF) == 1.0); + err |= !(fcmovu(ZF) == 1.0); err |= !(fcmovnu(ZF) != 1.0); + + err |= !(fcmovb(PF) == 1.0); err |= !(fcmovnb(PF) != 1.0); + err |= !(fcmove(PF) == 1.0); err |= !(fcmovne(PF) != 1.0); + err |= !(fcmovbe(PF) == 1.0); err |= !(fcmovnbe(PF) != 1.0); + err |= !(fcmovu(PF) != 1.0); err |= !(fcmovnu(PF) == 1.0); + + if (!err) + printf("[OK]\tfcmovCC\n"); + else + printf("[FAIL]\tfcmovCC errors: %d\n", err); + + return err; +} diff --git a/kernel/tools/testing/selftests/x86/test_FCOMI.c b/kernel/tools/testing/selftests/x86/test_FCOMI.c new file mode 100644 index 000000000..db4933e31 --- /dev/null +++ b/kernel/tools/testing/selftests/x86/test_FCOMI.c @@ -0,0 +1,331 @@ +#undef _GNU_SOURCE +#define _GNU_SOURCE 1 +#undef __USE_GNU +#define __USE_GNU 1 +#include <unistd.h> +#include <stdlib.h> +#include <string.h> +#include <stdio.h> +#include <signal.h> +#include <sys/types.h> +#include <sys/select.h> +#include <sys/time.h> +#include <sys/wait.h> +#include <fenv.h> + +enum { + CF = 1 << 0, + PF = 1 << 2, + ZF = 1 << 6, + ARITH = CF | PF | ZF, +}; + +long res_fcomi_pi_1; +long res_fcomi_1_pi; +long res_fcomi_1_1; +long res_fcomi_nan_1; +/* sNaN is s|111 1111 1|1xx xxxx xxxx xxxx xxxx xxxx */ +/* qNaN is s|111 1111 1|0xx xxxx xxxx xxxx xxxx xxxx (some x must be nonzero) */ +int snan = 0x7fc11111; +int qnan = 0x7f811111; +unsigned short snan1[5]; +/* sNaN80 is s|111 1111 1111 1111 |10xx xx...xx (some x must be nonzero) */ +unsigned short snan80[5] = { 0x1111, 0x1111, 0x1111, 0x8111, 0x7fff }; + +int test(long flags) +{ + feclearexcept(FE_DIVBYZERO|FE_INEXACT|FE_INVALID|FE_OVERFLOW|FE_UNDERFLOW); + + asm ("\n" + + " push %0""\n" + " popf""\n" + " fld1""\n" + " fldpi""\n" + " fcomi %%st(1), %%st" "\n" + " ffree %%st(0)" "\n" + " ffree %%st(1)" "\n" + " pushf""\n" + " pop res_fcomi_1_pi""\n" + + " push %0""\n" + " popf""\n" + " fldpi""\n" + " fld1""\n" + " fcomi %%st(1), %%st" "\n" + " ffree %%st(0)" "\n" + " ffree %%st(1)" "\n" + " pushf""\n" + " pop res_fcomi_pi_1""\n" + + " push %0""\n" + " popf""\n" + " fld1""\n" + " fld1""\n" + " fcomi %%st(1), %%st" "\n" + " ffree %%st(0)" "\n" + " ffree %%st(1)" "\n" + " pushf""\n" + " pop res_fcomi_1_1""\n" + : + : "r" (flags) + ); + if ((res_fcomi_1_pi & ARITH) != (0)) { + printf("[BAD]\tfcomi_1_pi with flags:%lx\n", flags); + return 1; + } + if ((res_fcomi_pi_1 & ARITH) != (CF)) { + printf("[BAD]\tfcomi_pi_1 with flags:%lx->%lx\n", flags, res_fcomi_pi_1 & ARITH); + return 1; + } + if ((res_fcomi_1_1 & ARITH) != (ZF)) { + printf("[BAD]\tfcomi_1_1 with flags:%lx\n", flags); + return 1; + } + if (fetestexcept(FE_INVALID) != 0) { + printf("[BAD]\tFE_INVALID is set in %s\n", __func__); + return 1; + } + return 0; +} + +int test_qnan(long flags) +{ + feclearexcept(FE_DIVBYZERO|FE_INEXACT|FE_INVALID|FE_OVERFLOW|FE_UNDERFLOW); + + asm ("\n" + " push %0""\n" + " popf""\n" + " flds qnan""\n" + " fld1""\n" + " fnclex""\n" // fld of a qnan raised FE_INVALID, clear it + " fcomi %%st(1), %%st" "\n" + " ffree %%st(0)" "\n" + " ffree %%st(1)" "\n" + " pushf""\n" + " pop res_fcomi_nan_1""\n" + : + : "r" (flags) + ); + if ((res_fcomi_nan_1 & ARITH) != (ZF|CF|PF)) { + printf("[BAD]\tfcomi_qnan_1 with flags:%lx\n", flags); + return 1; + } + if (fetestexcept(FE_INVALID) != FE_INVALID) { + printf("[BAD]\tFE_INVALID is not set in %s\n", __func__); + return 1; + } + return 0; +} + +int testu_qnan(long flags) +{ + feclearexcept(FE_DIVBYZERO|FE_INEXACT|FE_INVALID|FE_OVERFLOW|FE_UNDERFLOW); + + asm ("\n" + " push %0""\n" + " popf""\n" + " flds qnan""\n" + " fld1""\n" + " fnclex""\n" // fld of a qnan raised FE_INVALID, clear it + " fucomi %%st(1), %%st" "\n" + " ffree %%st(0)" "\n" + " ffree %%st(1)" "\n" + " pushf""\n" + " pop res_fcomi_nan_1""\n" + : + : "r" (flags) + ); + if ((res_fcomi_nan_1 & ARITH) != (ZF|CF|PF)) { + printf("[BAD]\tfcomi_qnan_1 with flags:%lx\n", flags); + return 1; + } + if (fetestexcept(FE_INVALID) != 0) { + printf("[BAD]\tFE_INVALID is set in %s\n", __func__); + return 1; + } + return 0; +} + +int testu_snan(long flags) +{ + feclearexcept(FE_DIVBYZERO|FE_INEXACT|FE_INVALID|FE_OVERFLOW|FE_UNDERFLOW); + + asm ("\n" + " push %0""\n" + " popf""\n" +// " flds snan""\n" // WRONG, this will convert 32-bit fp snan to a *qnan* in 80-bit fp register! +// " fstpt snan1""\n" // if uncommented, it prints "snan1:7fff c111 1100 0000 0000" - c111, not 8111! +// " fnclex""\n" // flds of a snan raised FE_INVALID, clear it + " fldt snan80""\n" // fldt never raise FE_INVALID + " fld1""\n" + " fucomi %%st(1), %%st" "\n" + " ffree %%st(0)" "\n" + " ffree %%st(1)" "\n" + " pushf""\n" + " pop res_fcomi_nan_1""\n" + : + : "r" (flags) + ); + if ((res_fcomi_nan_1 & ARITH) != (ZF|CF|PF)) { + printf("[BAD]\tfcomi_qnan_1 with flags:%lx\n", flags); + return 1; + } +// printf("snan:%x snan1:%04x %04x %04x %04x %04x\n", snan, snan1[4], snan1[3], snan1[2], snan1[1], snan1[0]); + if (fetestexcept(FE_INVALID) != FE_INVALID) { + printf("[BAD]\tFE_INVALID is not set in %s\n", __func__); + return 1; + } + return 0; +} + +int testp(long flags) +{ + feclearexcept(FE_DIVBYZERO|FE_INEXACT|FE_INVALID|FE_OVERFLOW|FE_UNDERFLOW); + + asm ("\n" + + " push %0""\n" + " popf""\n" + " fld1""\n" + " fldpi""\n" + " fcomip %%st(1), %%st" "\n" + " ffree %%st(0)" "\n" + " pushf""\n" + " pop res_fcomi_1_pi""\n" + + " push %0""\n" + " popf""\n" + " fldpi""\n" + " fld1""\n" + " fcomip %%st(1), %%st" "\n" + " ffree %%st(0)" "\n" + " pushf""\n" + " pop res_fcomi_pi_1""\n" + + " push %0""\n" + " popf""\n" + " fld1""\n" + " fld1""\n" + " fcomip %%st(1), %%st" "\n" + " ffree %%st(0)" "\n" + " pushf""\n" + " pop res_fcomi_1_1""\n" + : + : "r" (flags) + ); + if ((res_fcomi_1_pi & ARITH) != (0)) { + printf("[BAD]\tfcomi_1_pi with flags:%lx\n", flags); + return 1; + } + if ((res_fcomi_pi_1 & ARITH) != (CF)) { + printf("[BAD]\tfcomi_pi_1 with flags:%lx->%lx\n", flags, res_fcomi_pi_1 & ARITH); + return 1; + } + if ((res_fcomi_1_1 & ARITH) != (ZF)) { + printf("[BAD]\tfcomi_1_1 with flags:%lx\n", flags); + return 1; + } + if (fetestexcept(FE_INVALID) != 0) { + printf("[BAD]\tFE_INVALID is set in %s\n", __func__); + return 1; + } + return 0; +} + +int testp_qnan(long flags) +{ + feclearexcept(FE_DIVBYZERO|FE_INEXACT|FE_INVALID|FE_OVERFLOW|FE_UNDERFLOW); + + asm ("\n" + " push %0""\n" + " popf""\n" + " flds qnan""\n" + " fld1""\n" + " fnclex""\n" // fld of a qnan raised FE_INVALID, clear it + " fcomip %%st(1), %%st" "\n" + " ffree %%st(0)" "\n" + " pushf""\n" + " pop res_fcomi_nan_1""\n" + : + : "r" (flags) + ); + if ((res_fcomi_nan_1 & ARITH) != (ZF|CF|PF)) { + printf("[BAD]\tfcomi_qnan_1 with flags:%lx\n", flags); + return 1; + } + if (fetestexcept(FE_INVALID) != FE_INVALID) { + printf("[BAD]\tFE_INVALID is not set in %s\n", __func__); + return 1; + } + return 0; +} + +int testup_qnan(long flags) +{ + feclearexcept(FE_DIVBYZERO|FE_INEXACT|FE_INVALID|FE_OVERFLOW|FE_UNDERFLOW); + + asm ("\n" + " push %0""\n" + " popf""\n" + " flds qnan""\n" + " fld1""\n" + " fnclex""\n" // fld of a qnan raised FE_INVALID, clear it + " fucomip %%st(1), %%st" "\n" + " ffree %%st(0)" "\n" + " pushf""\n" + " pop res_fcomi_nan_1""\n" + : + : "r" (flags) + ); + if ((res_fcomi_nan_1 & ARITH) != (ZF|CF|PF)) { + printf("[BAD]\tfcomi_qnan_1 with flags:%lx\n", flags); + return 1; + } + if (fetestexcept(FE_INVALID) != 0) { + printf("[BAD]\tFE_INVALID is set in %s\n", __func__); + return 1; + } + return 0; +} + +void sighandler(int sig) +{ + printf("[FAIL]\tGot signal %d, exiting\n", sig); + exit(1); +} + +int main(int argc, char **argv, char **envp) +{ + int err = 0; + + /* SIGILL triggers on 32-bit kernels w/o fcomi emulation + * when run with "no387 nofxsr". Other signals are caught + * just in case. + */ + signal(SIGILL, sighandler); + signal(SIGFPE, sighandler); + signal(SIGSEGV, sighandler); + + printf("[RUN]\tTesting f[u]comi[p] instructions\n"); + err |= test(0); + err |= test_qnan(0); + err |= testu_qnan(0); + err |= testu_snan(0); + err |= test(CF|ZF|PF); + err |= test_qnan(CF|ZF|PF); + err |= testu_qnan(CF|ZF|PF); + err |= testu_snan(CF|ZF|PF); + err |= testp(0); + err |= testp_qnan(0); + err |= testup_qnan(0); + err |= testp(CF|ZF|PF); + err |= testp_qnan(CF|ZF|PF); + err |= testup_qnan(CF|ZF|PF); + if (!err) + printf("[OK]\tf[u]comi[p]\n"); + else + printf("[FAIL]\tf[u]comi[p] errors: %d\n", err); + + return err; +} diff --git a/kernel/tools/testing/selftests/x86/test_FISTTP.c b/kernel/tools/testing/selftests/x86/test_FISTTP.c new file mode 100644 index 000000000..b8e61a047 --- /dev/null +++ b/kernel/tools/testing/selftests/x86/test_FISTTP.c @@ -0,0 +1,137 @@ +#undef _GNU_SOURCE +#define _GNU_SOURCE 1 +#undef __USE_GNU +#define __USE_GNU 1 +#include <unistd.h> +#include <stdlib.h> +#include <string.h> +#include <stdio.h> +#include <signal.h> +#include <sys/types.h> +#include <sys/select.h> +#include <sys/time.h> +#include <sys/wait.h> +#include <fenv.h> + +unsigned long long res64 = -1; +unsigned int res32 = -1; +unsigned short res16 = -1; + +int test(void) +{ + int ex; + + feclearexcept(FE_DIVBYZERO|FE_INEXACT|FE_INVALID|FE_OVERFLOW|FE_UNDERFLOW); + asm volatile ("\n" + " fld1""\n" + " fisttp res16""\n" + " fld1""\n" + " fisttpl res32""\n" + " fld1""\n" + " fisttpll res64""\n" + : : : "memory" + ); + if (res16 != 1 || res32 != 1 || res64 != 1) { + printf("[BAD]\tfisttp 1\n"); + return 1; + } + ex = fetestexcept(FE_DIVBYZERO|FE_INEXACT|FE_INVALID|FE_OVERFLOW|FE_UNDERFLOW); + if (ex != 0) { + printf("[BAD]\tfisttp 1: wrong exception state\n"); + return 1; + } + + feclearexcept(FE_DIVBYZERO|FE_INEXACT|FE_INVALID|FE_OVERFLOW|FE_UNDERFLOW); + asm volatile ("\n" + " fldpi""\n" + " fisttp res16""\n" + " fldpi""\n" + " fisttpl res32""\n" + " fldpi""\n" + " fisttpll res64""\n" + : : : "memory" + ); + if (res16 != 3 || res32 != 3 || res64 != 3) { + printf("[BAD]\tfisttp pi\n"); + return 1; + } + ex = fetestexcept(FE_DIVBYZERO|FE_INEXACT|FE_INVALID|FE_OVERFLOW|FE_UNDERFLOW); + if (ex != FE_INEXACT) { + printf("[BAD]\tfisttp pi: wrong exception state\n"); + return 1; + } + + feclearexcept(FE_DIVBYZERO|FE_INEXACT|FE_INVALID|FE_OVERFLOW|FE_UNDERFLOW); + asm volatile ("\n" + " fldpi""\n" + " fchs""\n" + " fisttp res16""\n" + " fldpi""\n" + " fchs""\n" + " fisttpl res32""\n" + " fldpi""\n" + " fchs""\n" + " fisttpll res64""\n" + : : : "memory" + ); + if (res16 != 0xfffd || res32 != 0xfffffffd || res64 != 0xfffffffffffffffdULL) { + printf("[BAD]\tfisttp -pi\n"); + return 1; + } + ex = fetestexcept(FE_DIVBYZERO|FE_INEXACT|FE_INVALID|FE_OVERFLOW|FE_UNDERFLOW); + if (ex != FE_INEXACT) { + printf("[BAD]\tfisttp -pi: wrong exception state\n"); + return 1; + } + + feclearexcept(FE_DIVBYZERO|FE_INEXACT|FE_INVALID|FE_OVERFLOW|FE_UNDERFLOW); + asm volatile ("\n" + " fldln2""\n" + " fisttp res16""\n" + " fldln2""\n" + " fisttpl res32""\n" + " fldln2""\n" + " fisttpll res64""\n" + : : : "memory" + ); + /* Test truncation to zero (round-to-nearest would give 1 here) */ + if (res16 != 0 || res32 != 0 || res64 != 0) { + printf("[BAD]\tfisttp ln2\n"); + return 1; + } + ex = fetestexcept(FE_DIVBYZERO|FE_INEXACT|FE_INVALID|FE_OVERFLOW|FE_UNDERFLOW); + if (ex != FE_INEXACT) { + printf("[BAD]\tfisttp ln2: wrong exception state\n"); + return 1; + } + + return 0; +} + +void sighandler(int sig) +{ + printf("[FAIL]\tGot signal %d, exiting\n", sig); + exit(1); +} + +int main(int argc, char **argv, char **envp) +{ + int err = 0; + + /* SIGILL triggers on 32-bit kernels w/o fisttp emulation + * when run with "no387 nofxsr". Other signals are caught + * just in case. + */ + signal(SIGILL, sighandler); + signal(SIGFPE, sighandler); + signal(SIGSEGV, sighandler); + + printf("[RUN]\tTesting fisttp instructions\n"); + err |= test(); + if (!err) + printf("[OK]\tfisttp\n"); + else + printf("[FAIL]\tfisttp errors: %d\n", err); + + return err; +} diff --git a/kernel/tools/testing/selftests/x86/test_syscall_vdso.c b/kernel/tools/testing/selftests/x86/test_syscall_vdso.c new file mode 100644 index 000000000..40370354d --- /dev/null +++ b/kernel/tools/testing/selftests/x86/test_syscall_vdso.c @@ -0,0 +1,401 @@ +/* + * 32-bit syscall ABI conformance test. + * + * Copyright (c) 2015 Denys Vlasenko + * + * This program is free software; you can redistribute it and/or modify + * it under the terms and conditions of the GNU General Public License, + * version 2, as published by the Free Software Foundation. + * + * This program is distributed in the hope it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + */ +/* + * Can be built statically: + * gcc -Os -Wall -static -m32 test_syscall_vdso.c thunks_32.S + */ +#undef _GNU_SOURCE +#define _GNU_SOURCE 1 +#undef __USE_GNU +#define __USE_GNU 1 +#include <unistd.h> +#include <stdlib.h> +#include <string.h> +#include <stdio.h> +#include <signal.h> +#include <sys/types.h> +#include <sys/select.h> +#include <sys/time.h> +#include <elf.h> +#include <sys/ptrace.h> +#include <sys/wait.h> + +#if !defined(__i386__) +int main(int argc, char **argv, char **envp) +{ + printf("[SKIP]\tNot a 32-bit x86 userspace\n"); + return 0; +} +#else + +long syscall_addr; +long get_syscall(char **envp) +{ + Elf32_auxv_t *auxv; + while (*envp++ != NULL) + continue; + for (auxv = (void *)envp; auxv->a_type != AT_NULL; auxv++) + if (auxv->a_type == AT_SYSINFO) + return auxv->a_un.a_val; + printf("[WARN]\tAT_SYSINFO not supplied\n"); + return 0; +} + +asm ( + " .pushsection .text\n" + " .global int80\n" + "int80:\n" + " int $0x80\n" + " ret\n" + " .popsection\n" +); +extern char int80; + +struct regs64 { + uint64_t rax, rbx, rcx, rdx; + uint64_t rsi, rdi, rbp, rsp; + uint64_t r8, r9, r10, r11; + uint64_t r12, r13, r14, r15; +}; +struct regs64 regs64; +int kernel_is_64bit; + +asm ( + " .pushsection .text\n" + " .code64\n" + "get_regs64:\n" + " push %rax\n" + " mov $regs64, %eax\n" + " pop 0*8(%rax)\n" + " movq %rbx, 1*8(%rax)\n" + " movq %rcx, 2*8(%rax)\n" + " movq %rdx, 3*8(%rax)\n" + " movq %rsi, 4*8(%rax)\n" + " movq %rdi, 5*8(%rax)\n" + " movq %rbp, 6*8(%rax)\n" + " movq %rsp, 7*8(%rax)\n" + " movq %r8, 8*8(%rax)\n" + " movq %r9, 9*8(%rax)\n" + " movq %r10, 10*8(%rax)\n" + " movq %r11, 11*8(%rax)\n" + " movq %r12, 12*8(%rax)\n" + " movq %r13, 13*8(%rax)\n" + " movq %r14, 14*8(%rax)\n" + " movq %r15, 15*8(%rax)\n" + " ret\n" + "poison_regs64:\n" + " movq $0x7f7f7f7f, %r8\n" + " shl $32, %r8\n" + " orq $0x7f7f7f7f, %r8\n" + " movq %r8, %r9\n" + " movq %r8, %r10\n" + " movq %r8, %r11\n" + " movq %r8, %r12\n" + " movq %r8, %r13\n" + " movq %r8, %r14\n" + " movq %r8, %r15\n" + " ret\n" + " .code32\n" + " .popsection\n" +); +extern void get_regs64(void); +extern void poison_regs64(void); +extern unsigned long call64_from_32(void (*function)(void)); +void print_regs64(void) +{ + if (!kernel_is_64bit) + return; + printf("ax:%016llx bx:%016llx cx:%016llx dx:%016llx\n", regs64.rax, regs64.rbx, regs64.rcx, regs64.rdx); + printf("si:%016llx di:%016llx bp:%016llx sp:%016llx\n", regs64.rsi, regs64.rdi, regs64.rbp, regs64.rsp); + printf(" 8:%016llx 9:%016llx 10:%016llx 11:%016llx\n", regs64.r8 , regs64.r9 , regs64.r10, regs64.r11); + printf("12:%016llx 13:%016llx 14:%016llx 15:%016llx\n", regs64.r12, regs64.r13, regs64.r14, regs64.r15); +} + +int check_regs64(void) +{ + int err = 0; + int num = 8; + uint64_t *r64 = ®s64.r8; + + if (!kernel_is_64bit) + return 0; + + do { + if (*r64 == 0x7f7f7f7f7f7f7f7fULL) + continue; /* register did not change */ + if (syscall_addr != (long)&int80) { + /* + * Non-INT80 syscall entrypoints are allowed to clobber R8+ regs: + * either clear them to 0, or for R11, load EFLAGS. + */ + if (*r64 == 0) + continue; + if (num == 11) { + printf("[NOTE]\tR11 has changed:%016llx - assuming clobbered by SYSRET insn\n", *r64); + continue; + } + } else { + /* INT80 syscall entrypoint can be used by + * 64-bit programs too, unlike SYSCALL/SYSENTER. + * Therefore it must preserve R12+ + * (they are callee-saved registers in 64-bit C ABI). + * + * This was probably historically not intended, + * but R8..11 are clobbered (cleared to 0). + * IOW: they are the only registers which aren't + * preserved across INT80 syscall. + */ + if (*r64 == 0 && num <= 11) + continue; + } + printf("[FAIL]\tR%d has changed:%016llx\n", num, *r64); + err++; + } while (r64++, ++num < 16); + + if (!err) + printf("[OK]\tR8..R15 did not leak kernel data\n"); + return err; +} + +int nfds; +fd_set rfds; +fd_set wfds; +fd_set efds; +struct timespec timeout; +sigset_t sigmask; +struct { + sigset_t *sp; + int sz; +} sigmask_desc; + +void prep_args() +{ + nfds = 42; + FD_ZERO(&rfds); + FD_ZERO(&wfds); + FD_ZERO(&efds); + FD_SET(0, &rfds); + FD_SET(1, &wfds); + FD_SET(2, &efds); + timeout.tv_sec = 0; + timeout.tv_nsec = 123; + sigemptyset(&sigmask); + sigaddset(&sigmask, SIGINT); + sigaddset(&sigmask, SIGUSR2); + sigaddset(&sigmask, SIGRTMAX); + sigmask_desc.sp = &sigmask; + sigmask_desc.sz = 8; /* bytes */ +} + +static void print_flags(const char *name, unsigned long r) +{ + static const char *bitarray[] = { + "\n" ,"c\n" ,/* Carry Flag */ + "0 " ,"1 " ,/* Bit 1 - always on */ + "" ,"p " ,/* Parity Flag */ + "0 " ,"3? " , + "" ,"a " ,/* Auxiliary carry Flag */ + "0 " ,"5? " , + "" ,"z " ,/* Zero Flag */ + "" ,"s " ,/* Sign Flag */ + "" ,"t " ,/* Trap Flag */ + "" ,"i " ,/* Interrupt Flag */ + "" ,"d " ,/* Direction Flag */ + "" ,"o " ,/* Overflow Flag */ + "0 " ,"1 " ,/* I/O Privilege Level (2 bits) */ + "0" ,"1" ,/* I/O Privilege Level (2 bits) */ + "" ,"n " ,/* Nested Task */ + "0 " ,"15? ", + "" ,"r " ,/* Resume Flag */ + "" ,"v " ,/* Virtual Mode */ + "" ,"ac " ,/* Alignment Check/Access Control */ + "" ,"vif ",/* Virtual Interrupt Flag */ + "" ,"vip ",/* Virtual Interrupt Pending */ + "" ,"id " ,/* CPUID detection */ + NULL + }; + const char **bitstr; + int bit; + + printf("%s=%016lx ", name, r); + bitstr = bitarray + 42; + bit = 21; + if ((r >> 22) != 0) + printf("(extra bits are set) "); + do { + if (bitstr[(r >> bit) & 1][0]) + fputs(bitstr[(r >> bit) & 1], stdout); + bitstr -= 2; + bit--; + } while (bit >= 0); +} + +int run_syscall(void) +{ + long flags, bad_arg; + + prep_args(); + + if (kernel_is_64bit) + call64_from_32(poison_regs64); + /*print_regs64();*/ + + asm("\n" + /* Try 6-arg syscall: pselect. It should return quickly */ + " push %%ebp\n" + " mov $308, %%eax\n" /* PSELECT */ + " mov nfds, %%ebx\n" /* ebx arg1 */ + " mov $rfds, %%ecx\n" /* ecx arg2 */ + " mov $wfds, %%edx\n" /* edx arg3 */ + " mov $efds, %%esi\n" /* esi arg4 */ + " mov $timeout, %%edi\n" /* edi arg5 */ + " mov $sigmask_desc, %%ebp\n" /* %ebp arg6 */ + " push $0x200ed7\n" /* set almost all flags */ + " popf\n" /* except TF, IOPL, NT, RF, VM, AC, VIF, VIP */ + " call *syscall_addr\n" + /* Check that registers are not clobbered */ + " pushf\n" + " pop %%eax\n" + " cld\n" + " cmp nfds, %%ebx\n" /* ebx arg1 */ + " mov $1, %%ebx\n" + " jne 1f\n" + " cmp $rfds, %%ecx\n" /* ecx arg2 */ + " mov $2, %%ebx\n" + " jne 1f\n" + " cmp $wfds, %%edx\n" /* edx arg3 */ + " mov $3, %%ebx\n" + " jne 1f\n" + " cmp $efds, %%esi\n" /* esi arg4 */ + " mov $4, %%ebx\n" + " jne 1f\n" + " cmp $timeout, %%edi\n" /* edi arg5 */ + " mov $5, %%ebx\n" + " jne 1f\n" + " cmpl $sigmask_desc, %%ebp\n" /* %ebp arg6 */ + " mov $6, %%ebx\n" + " jne 1f\n" + " mov $0, %%ebx\n" + "1:\n" + " pop %%ebp\n" + : "=a" (flags), "=b" (bad_arg) + : + : "cx", "dx", "si", "di" + ); + + if (kernel_is_64bit) { + memset(®s64, 0x77, sizeof(regs64)); + call64_from_32(get_regs64); + /*print_regs64();*/ + } + + /* + * On paravirt kernels, flags are not preserved across syscalls. + * Thus, we do not consider it a bug if some are changed. + * We just show ones which do. + */ + if ((0x200ed7 ^ flags) != 0) { + print_flags("[WARN]\tFlags before", 0x200ed7); + print_flags("[WARN]\tFlags after", flags); + print_flags("[WARN]\tFlags change", (0x200ed7 ^ flags)); + } + + if (bad_arg) { + printf("[FAIL]\targ#%ld clobbered\n", bad_arg); + return 1; + } + printf("[OK]\tArguments are preserved across syscall\n"); + + return check_regs64(); +} + +int run_syscall_twice() +{ + int exitcode = 0; + long sv; + + if (syscall_addr) { + printf("[RUN]\tExecuting 6-argument 32-bit syscall via VDSO\n"); + exitcode = run_syscall(); + } + sv = syscall_addr; + syscall_addr = (long)&int80; + printf("[RUN]\tExecuting 6-argument 32-bit syscall via INT 80\n"); + exitcode += run_syscall(); + syscall_addr = sv; + return exitcode; +} + +void ptrace_me() +{ + pid_t pid; + + fflush(NULL); + pid = fork(); + if (pid < 0) + exit(1); + if (pid == 0) { + /* child */ + if (ptrace(PTRACE_TRACEME, 0L, 0L, 0L) != 0) + exit(0); + raise(SIGSTOP); + return; + } + /* parent */ + printf("[RUN]\tRunning tests under ptrace\n"); + while (1) { + int status; + pid = waitpid(-1, &status, __WALL); + if (WIFEXITED(status)) + exit(WEXITSTATUS(status)); + if (WIFSIGNALED(status)) + exit(WTERMSIG(status)); + if (pid <= 0 || !WIFSTOPPED(status)) /* paranoia */ + exit(255); + /* + * Note: we do not inject sig = WSTOPSIG(status). + * We probably should, but careful: do not inject SIGTRAP + * generated by syscall entry/exit stops. + * That kills the child. + */ + ptrace(PTRACE_SYSCALL, pid, 0L, 0L /*sig*/); + } +} + +int main(int argc, char **argv, char **envp) +{ + int exitcode = 0; + int cs; + + asm("\n" + " movl %%cs, %%eax\n" + : "=a" (cs) + ); + kernel_is_64bit = (cs == 0x23); + if (!kernel_is_64bit) + printf("[NOTE]\tNot a 64-bit kernel, won't test R8..R15 leaks\n"); + + /* This only works for non-static builds: + * syscall_addr = dlsym(dlopen("linux-gate.so.1", RTLD_NOW), "__kernel_vsyscall"); + */ + syscall_addr = get_syscall(envp); + + exitcode += run_syscall_twice(); + ptrace_me(); + exitcode += run_syscall_twice(); + + return exitcode; +} +#endif diff --git a/kernel/tools/testing/selftests/x86/thunks.S b/kernel/tools/testing/selftests/x86/thunks.S new file mode 100644 index 000000000..ce8a995bb --- /dev/null +++ b/kernel/tools/testing/selftests/x86/thunks.S @@ -0,0 +1,67 @@ +/* + * thunks.S - assembly helpers for mixed-bitness code + * Copyright (c) 2015 Andrew Lutomirski + * + * This program is free software; you can redistribute it and/or modify + * it under the terms and conditions of the GNU General Public License, + * version 2, as published by the Free Software Foundation. + * + * This program is distributed in the hope it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * These are little helpers that make it easier to switch bitness on + * the fly. + */ + + .text + + .global call32_from_64 + .type call32_from_64, @function +call32_from_64: + // rdi: stack to use + // esi: function to call + + // Save registers + pushq %rbx + pushq %rbp + pushq %r12 + pushq %r13 + pushq %r14 + pushq %r15 + pushfq + + // Switch stacks + mov %rsp,(%rdi) + mov %rdi,%rsp + + // Switch to compatibility mode + pushq $0x23 /* USER32_CS */ + pushq $1f + lretq + +1: + .code32 + // Call the function + call *%esi + // Switch back to long mode + jmp $0x33,$1f + .code64 + +1: + // Restore the stack + mov (%rsp),%rsp + + // Restore registers + popfq + popq %r15 + popq %r14 + popq %r13 + popq %r12 + popq %rbp + popq %rbx + + ret + +.size call32_from_64, .-call32_from_64 diff --git a/kernel/tools/testing/selftests/x86/thunks_32.S b/kernel/tools/testing/selftests/x86/thunks_32.S new file mode 100644 index 000000000..29b644bb9 --- /dev/null +++ b/kernel/tools/testing/selftests/x86/thunks_32.S @@ -0,0 +1,55 @@ +/* + * thunks_32.S - assembly helpers for mixed-bitness code + * Copyright (c) 2015 Denys Vlasenko + * + * This program is free software; you can redistribute it and/or modify + * it under the terms and conditions of the GNU General Public License, + * version 2, as published by the Free Software Foundation. + * + * This program is distributed in the hope it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * These are little helpers that make it easier to switch bitness on + * the fly. + */ + + .text + .code32 + + .global call64_from_32 + .type call32_from_64, @function + + // 4(%esp): function to call +call64_from_32: + // Fetch function address + mov 4(%esp), %eax + + // Save registers which are callee-clobbered by 64-bit ABI + push %ecx + push %edx + push %esi + push %edi + + // Switch to long mode + jmp $0x33,$1f +1: .code64 + + // Call the function + call *%rax + + // Switch to compatibility mode + push $0x23 /* USER32_CS */ + .code32; push $1f; .code64 /* hack: can't have X86_64_32S relocation in 32-bit ELF */ + lretq +1: .code32 + + pop %edi + pop %esi + pop %edx + pop %ecx + + ret + +.size call64_from_32, .-call64_from_32 diff --git a/kernel/tools/testing/selftests/x86/trivial_64bit_program.c b/kernel/tools/testing/selftests/x86/trivial_64bit_program.c index b994946c4..05c6a41b3 100644 --- a/kernel/tools/testing/selftests/x86/trivial_64bit_program.c +++ b/kernel/tools/testing/selftests/x86/trivial_64bit_program.c @@ -1,5 +1,5 @@ /* - * Trivial program to check that we have a valid 32-bit build environment. + * Trivial program to check that we have a valid 64-bit build environment. * Copyright (c) 2015 Andy Lutomirski * GPL v2 */ diff --git a/kernel/tools/testing/selftests/x86/unwind_vdso.c b/kernel/tools/testing/selftests/x86/unwind_vdso.c new file mode 100644 index 000000000..00a26a82f --- /dev/null +++ b/kernel/tools/testing/selftests/x86/unwind_vdso.c @@ -0,0 +1,211 @@ +/* + * unwind_vdso.c - tests unwind info for AT_SYSINFO in the vDSO + * Copyright (c) 2014-2015 Andrew Lutomirski + * + * This program is free software; you can redistribute it and/or modify + * it under the terms and conditions of the GNU General Public License, + * version 2, as published by the Free Software Foundation. + * + * This program is distributed in the hope it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * This tests __kernel_vsyscall's unwind info. + */ + +#define _GNU_SOURCE + +#include <features.h> +#include <stdio.h> + +#if defined(__GLIBC__) && __GLIBC__ == 2 && __GLIBC_MINOR__ < 16 + +int main() +{ + /* We need getauxval(). */ + printf("[SKIP]\tGLIBC before 2.16 cannot compile this test\n"); + return 0; +} + +#else + +#include <sys/time.h> +#include <stdlib.h> +#include <syscall.h> +#include <unistd.h> +#include <string.h> +#include <inttypes.h> +#include <sys/mman.h> +#include <signal.h> +#include <sys/ucontext.h> +#include <err.h> +#include <stddef.h> +#include <stdbool.h> +#include <sys/ptrace.h> +#include <sys/user.h> +#include <sys/ucontext.h> +#include <link.h> +#include <sys/auxv.h> +#include <dlfcn.h> +#include <unwind.h> + +static void sethandler(int sig, void (*handler)(int, siginfo_t *, void *), + int flags) +{ + struct sigaction sa; + memset(&sa, 0, sizeof(sa)); + sa.sa_sigaction = handler; + sa.sa_flags = SA_SIGINFO | flags; + sigemptyset(&sa.sa_mask); + if (sigaction(sig, &sa, 0)) + err(1, "sigaction"); +} + +#ifdef __x86_64__ +# define WIDTH "q" +#else +# define WIDTH "l" +#endif + +static unsigned long get_eflags(void) +{ + unsigned long eflags; + asm volatile ("pushf" WIDTH "\n\tpop" WIDTH " %0" : "=rm" (eflags)); + return eflags; +} + +static void set_eflags(unsigned long eflags) +{ + asm volatile ("push" WIDTH " %0\n\tpopf" WIDTH + : : "rm" (eflags) : "flags"); +} + +#define X86_EFLAGS_TF (1UL << 8) + +static volatile sig_atomic_t nerrs; +static unsigned long sysinfo; +static bool got_sysinfo = false; +static unsigned long return_address; + +struct unwind_state { + unsigned long ip; /* trap source */ + int depth; /* -1 until we hit the trap source */ +}; + +_Unwind_Reason_Code trace_fn(struct _Unwind_Context * ctx, void *opaque) +{ + struct unwind_state *state = opaque; + unsigned long ip = _Unwind_GetIP(ctx); + + if (state->depth == -1) { + if (ip == state->ip) + state->depth = 0; + else + return _URC_NO_REASON; /* Not there yet */ + } + printf("\t 0x%lx\n", ip); + + if (ip == return_address) { + /* Here we are. */ + unsigned long eax = _Unwind_GetGR(ctx, 0); + unsigned long ecx = _Unwind_GetGR(ctx, 1); + unsigned long edx = _Unwind_GetGR(ctx, 2); + unsigned long ebx = _Unwind_GetGR(ctx, 3); + unsigned long ebp = _Unwind_GetGR(ctx, 5); + unsigned long esi = _Unwind_GetGR(ctx, 6); + unsigned long edi = _Unwind_GetGR(ctx, 7); + bool ok = (eax == SYS_getpid || eax == getpid()) && + ebx == 1 && ecx == 2 && edx == 3 && + esi == 4 && edi == 5 && ebp == 6; + + if (!ok) + nerrs++; + printf("[%s]\t NR = %ld, args = %ld, %ld, %ld, %ld, %ld, %ld\n", + (ok ? "OK" : "FAIL"), + eax, ebx, ecx, edx, esi, edi, ebp); + + return _URC_NORMAL_STOP; + } else { + state->depth++; + return _URC_NO_REASON; + } +} + +static void sigtrap(int sig, siginfo_t *info, void *ctx_void) +{ + ucontext_t *ctx = (ucontext_t *)ctx_void; + struct unwind_state state; + unsigned long ip = ctx->uc_mcontext.gregs[REG_EIP]; + + if (!got_sysinfo && ip == sysinfo) { + got_sysinfo = true; + + /* Find the return address. */ + return_address = *(unsigned long *)(unsigned long)ctx->uc_mcontext.gregs[REG_ESP]; + + printf("\tIn vsyscall at 0x%lx, returning to 0x%lx\n", + ip, return_address); + } + + if (!got_sysinfo) + return; /* Not there yet */ + + if (ip == return_address) { + ctx->uc_mcontext.gregs[REG_EFL] &= ~X86_EFLAGS_TF; + printf("\tVsyscall is done\n"); + return; + } + + printf("\tSIGTRAP at 0x%lx\n", ip); + + state.ip = ip; + state.depth = -1; + _Unwind_Backtrace(trace_fn, &state); +} + +int main() +{ + sysinfo = getauxval(AT_SYSINFO); + printf("\tAT_SYSINFO is 0x%lx\n", sysinfo); + + Dl_info info; + if (!dladdr((void *)sysinfo, &info)) { + printf("[WARN]\tdladdr failed on AT_SYSINFO\n"); + } else { + printf("[OK]\tAT_SYSINFO maps to %s, loaded at 0x%p\n", + info.dli_fname, info.dli_fbase); + } + + sethandler(SIGTRAP, sigtrap, 0); + + syscall(SYS_getpid); /* Force symbol binding without TF set. */ + printf("[RUN]\tSet TF and check a fast syscall\n"); + set_eflags(get_eflags() | X86_EFLAGS_TF); + syscall(SYS_getpid, 1, 2, 3, 4, 5, 6); + if (!got_sysinfo) { + set_eflags(get_eflags() & ~X86_EFLAGS_TF); + + /* + * The most likely cause of this is that you're on Debian or + * a Debian-based distro, you're missing libc6-i686, and you're + * affected by libc/19006 (https://sourceware.org/PR19006). + */ + printf("[WARN]\tsyscall(2) didn't enter AT_SYSINFO\n"); + } + + if (get_eflags() & X86_EFLAGS_TF) { + printf("[FAIL]\tTF is still set\n"); + nerrs++; + } + + if (nerrs) { + printf("[FAIL]\tThere were errors\n"); + return 1; + } else { + printf("[OK]\tAll is well\n"); + return 0; + } +} + +#endif /* New enough libc */ |