diff options
Diffstat (limited to 'kernel/arch/tile/kernel/ptrace.c')
| -rw-r--r-- | kernel/arch/tile/kernel/ptrace.c | 325 |
1 files changed, 325 insertions, 0 deletions
diff --git a/kernel/arch/tile/kernel/ptrace.c b/kernel/arch/tile/kernel/ptrace.c new file mode 100644 index 000000000..f84eed824 --- /dev/null +++ b/kernel/arch/tile/kernel/ptrace.c @@ -0,0 +1,325 @@ +/* + * Copyright 2010 Tilera Corporation. All Rights Reserved. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation, version 2. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or + * NON INFRINGEMENT. See the GNU General Public License for + * more details. + * + * Copied from i386: Ross Biro 1/23/92 + */ + +#include <linux/kernel.h> +#include <linux/ptrace.h> +#include <linux/kprobes.h> +#include <linux/compat.h> +#include <linux/uaccess.h> +#include <linux/regset.h> +#include <linux/elf.h> +#include <linux/tracehook.h> +#include <linux/context_tracking.h> +#include <asm/traps.h> +#include <arch/chip.h> + +#define CREATE_TRACE_POINTS +#include <trace/events/syscalls.h> + +void user_enable_single_step(struct task_struct *child) +{ + set_tsk_thread_flag(child, TIF_SINGLESTEP); +} + +void user_disable_single_step(struct task_struct *child) +{ + clear_tsk_thread_flag(child, TIF_SINGLESTEP); +} + +/* + * Called by kernel/ptrace.c when detaching.. + */ +void ptrace_disable(struct task_struct *child) +{ + clear_tsk_thread_flag(child, TIF_SINGLESTEP); + + /* + * These two are currently unused, but will be set by arch_ptrace() + * and used in the syscall assembly when we do support them. + */ + clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); +} + +/* + * Get registers from task and ready the result for userspace. + * Note that we localize the API issues to getregs() and putregs() at + * some cost in performance, e.g. we need a full pt_regs copy for + * PEEKUSR, and two copies for POKEUSR. But in general we expect + * GETREGS/PUTREGS to be the API of choice anyway. + */ +static char *getregs(struct task_struct *child, struct pt_regs *uregs) +{ + *uregs = *task_pt_regs(child); + + /* Set up flags ABI bits. */ + uregs->flags = 0; +#ifdef CONFIG_COMPAT + if (task_thread_info(child)->status & TS_COMPAT) + uregs->flags |= PT_FLAGS_COMPAT; +#endif + + return (char *)uregs; +} + +/* Put registers back to task. */ +static void putregs(struct task_struct *child, struct pt_regs *uregs) +{ + struct pt_regs *regs = task_pt_regs(child); + + /* Don't allow overwriting the kernel-internal flags word. */ + uregs->flags = regs->flags; + + /* Only allow setting the ICS bit in the ex1 word. */ + uregs->ex1 = PL_ICS_EX1(USER_PL, EX1_ICS(uregs->ex1)); + + *regs = *uregs; +} + +enum tile_regset { + REGSET_GPR, +}; + +static int tile_gpr_get(struct task_struct *target, + const struct user_regset *regset, + unsigned int pos, unsigned int count, + void *kbuf, void __user *ubuf) +{ + struct pt_regs regs; + + getregs(target, ®s); + + return user_regset_copyout(&pos, &count, &kbuf, &ubuf, ®s, 0, + sizeof(regs)); +} + +static int tile_gpr_set(struct task_struct *target, + const struct user_regset *regset, + unsigned int pos, unsigned int count, + const void *kbuf, const void __user *ubuf) +{ + int ret; + struct pt_regs regs; + + ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, ®s, 0, + sizeof(regs)); + if (ret) + return ret; + + putregs(target, ®s); + + return 0; +} + +static const struct user_regset tile_user_regset[] = { + [REGSET_GPR] = { + .core_note_type = NT_PRSTATUS, + .n = ELF_NGREG, + .size = sizeof(elf_greg_t), + .align = sizeof(elf_greg_t), + .get = tile_gpr_get, + .set = tile_gpr_set, + }, +}; + +static const struct user_regset_view tile_user_regset_view = { + .name = CHIP_ARCH_NAME, + .e_machine = ELF_ARCH, + .ei_osabi = ELF_OSABI, + .regsets = tile_user_regset, + .n = ARRAY_SIZE(tile_user_regset), +}; + +const struct user_regset_view *task_user_regset_view(struct task_struct *task) +{ + return &tile_user_regset_view; +} + +long arch_ptrace(struct task_struct *child, long request, + unsigned long addr, unsigned long data) +{ + unsigned long __user *datap = (long __user __force *)data; + unsigned long tmp; + long ret = -EIO; + char *childreg; + struct pt_regs copyregs; + + switch (request) { + + case PTRACE_PEEKUSR: /* Read register from pt_regs. */ + if (addr >= PTREGS_SIZE) + break; + childreg = getregs(child, ©regs) + addr; +#ifdef CONFIG_COMPAT + if (is_compat_task()) { + if (addr & (sizeof(compat_long_t)-1)) + break; + ret = put_user(*(compat_long_t *)childreg, + (compat_long_t __user *)datap); + } else +#endif + { + if (addr & (sizeof(long)-1)) + break; + ret = put_user(*(long *)childreg, datap); + } + break; + + case PTRACE_POKEUSR: /* Write register in pt_regs. */ + if (addr >= PTREGS_SIZE) + break; + childreg = getregs(child, ©regs) + addr; +#ifdef CONFIG_COMPAT + if (is_compat_task()) { + if (addr & (sizeof(compat_long_t)-1)) + break; + *(compat_long_t *)childreg = data; + } else +#endif + { + if (addr & (sizeof(long)-1)) + break; + *(long *)childreg = data; + } + putregs(child, ©regs); + ret = 0; + break; + + case PTRACE_GETREGS: /* Get all registers from the child. */ + ret = copy_regset_to_user(child, &tile_user_regset_view, + REGSET_GPR, 0, + sizeof(struct pt_regs), datap); + break; + + case PTRACE_SETREGS: /* Set all registers in the child. */ + ret = copy_regset_from_user(child, &tile_user_regset_view, + REGSET_GPR, 0, + sizeof(struct pt_regs), datap); + break; + + case PTRACE_GETFPREGS: /* Get the child FPU state. */ + case PTRACE_SETFPREGS: /* Set the child FPU state. */ + break; + + case PTRACE_SETOPTIONS: + /* Support TILE-specific ptrace options. */ + BUILD_BUG_ON(PTRACE_O_MASK_TILE & PTRACE_O_MASK); + tmp = data & PTRACE_O_MASK_TILE; + data &= ~PTRACE_O_MASK_TILE; + ret = ptrace_request(child, request, addr, data); + if (ret == 0) { + unsigned int flags = child->ptrace; + flags &= ~(PTRACE_O_MASK_TILE << PT_OPT_FLAG_SHIFT); + flags |= (tmp << PT_OPT_FLAG_SHIFT); + child->ptrace = flags; + } + break; + + default: +#ifdef CONFIG_COMPAT + if (task_thread_info(current)->status & TS_COMPAT) { + ret = compat_ptrace_request(child, request, + addr, data); + break; + } +#endif + ret = ptrace_request(child, request, addr, data); + break; + } + + return ret; +} + +#ifdef CONFIG_COMPAT +/* Not used; we handle compat issues in arch_ptrace() directly. */ +long compat_arch_ptrace(struct task_struct *child, compat_long_t request, + compat_ulong_t addr, compat_ulong_t data) +{ + BUG(); +} +#endif + +int do_syscall_trace_enter(struct pt_regs *regs) +{ + u32 work = ACCESS_ONCE(current_thread_info()->flags); + + /* + * If TIF_NOHZ is set, we are required to call user_exit() before + * doing anything that could touch RCU. + */ + if (work & _TIF_NOHZ) + user_exit(); + + if (work & _TIF_SYSCALL_TRACE) { + if (tracehook_report_syscall_entry(regs)) + regs->regs[TREG_SYSCALL_NR] = -1; + } + + if (work & _TIF_SYSCALL_TRACEPOINT) + trace_sys_enter(regs, regs->regs[TREG_SYSCALL_NR]); + + return regs->regs[TREG_SYSCALL_NR]; +} + +void do_syscall_trace_exit(struct pt_regs *regs) +{ + long errno; + + /* + * We may come here right after calling schedule_user() + * in which case we can be in RCU user mode. + */ + user_exit(); + + /* + * The standard tile calling convention returns the value (or negative + * errno) in r0, and zero (or positive errno) in r1. + * It saves a couple of cycles on the hot path to do this work in + * registers only as we return, rather than updating the in-memory + * struct ptregs. + */ + errno = (long) regs->regs[0]; + if (errno < 0 && errno > -4096) + regs->regs[1] = -errno; + else + regs->regs[1] = 0; + + if (test_thread_flag(TIF_SYSCALL_TRACE)) + tracehook_report_syscall_exit(regs, 0); + + if (test_thread_flag(TIF_SYSCALL_TRACEPOINT)) + trace_sys_exit(regs, regs->regs[0]); +} + +void send_sigtrap(struct task_struct *tsk, struct pt_regs *regs) +{ + struct siginfo info; + + memset(&info, 0, sizeof(info)); + info.si_signo = SIGTRAP; + info.si_code = TRAP_BRKPT; + info.si_addr = (void __user *) regs->pc; + + /* Send us the fakey SIGTRAP */ + force_sig_info(SIGTRAP, &info, tsk); +} + +/* Handle synthetic interrupt delivered only by the simulator. */ +void __kprobes do_breakpoint(struct pt_regs* regs, int fault_num) +{ + enum ctx_state prev_state = exception_enter(); + send_sigtrap(current, regs); + exception_exit(prev_state); +} |