diff options
Diffstat (limited to 'kernel/arch/um/os-Linux/skas/mem.c')
| -rw-r--r-- | kernel/arch/um/os-Linux/skas/mem.c | 207 |
1 files changed, 207 insertions, 0 deletions
diff --git a/kernel/arch/um/os-Linux/skas/mem.c b/kernel/arch/um/os-Linux/skas/mem.c new file mode 100644 index 000000000..e7f8c945a --- /dev/null +++ b/kernel/arch/um/os-Linux/skas/mem.c @@ -0,0 +1,207 @@ +/* + * Copyright (C) 2002 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com) + * Licensed under the GPL + */ + +#include <stddef.h> +#include <unistd.h> +#include <errno.h> +#include <string.h> +#include <sys/mman.h> +#include <init.h> +#include <as-layout.h> +#include <mm_id.h> +#include <os.h> +#include <ptrace_user.h> +#include <registers.h> +#include <skas.h> +#include <sysdep/ptrace.h> +#include <sysdep/stub.h> + +extern unsigned long batch_syscall_stub, __syscall_stub_start; + +extern void wait_stub_done(int pid); + +static inline unsigned long *check_init_stack(struct mm_id * mm_idp, + unsigned long *stack) +{ + if (stack == NULL) { + stack = (unsigned long *) mm_idp->stack + 2; + *stack = 0; + } + return stack; +} + +static unsigned long syscall_regs[MAX_REG_NR]; + +static int __init init_syscall_regs(void) +{ + get_safe_registers(syscall_regs, NULL); + syscall_regs[REGS_IP_INDEX] = STUB_CODE + + ((unsigned long) &batch_syscall_stub - + (unsigned long) &__syscall_stub_start); + return 0; +} + +__initcall(init_syscall_regs); + +static inline long do_syscall_stub(struct mm_id * mm_idp, void **addr) +{ + int n, i; + long ret, offset; + unsigned long * data; + unsigned long * syscall; + int err, pid = mm_idp->u.pid; + + n = ptrace_setregs(pid, syscall_regs); + if (n < 0) { + printk(UM_KERN_ERR "Registers - \n"); + for (i = 0; i < MAX_REG_NR; i++) + printk(UM_KERN_ERR "\t%d\t0x%lx\n", i, syscall_regs[i]); + panic("do_syscall_stub : PTRACE_SETREGS failed, errno = %d\n", + -n); + } + + err = ptrace(PTRACE_CONT, pid, 0, 0); + if (err) + panic("Failed to continue stub, pid = %d, errno = %d\n", pid, + errno); + + wait_stub_done(pid); + + /* + * When the stub stops, we find the following values on the + * beginning of the stack: + * (long )return_value + * (long )offset to failed sycall-data (0, if no error) + */ + ret = *((unsigned long *) mm_idp->stack); + offset = *((unsigned long *) mm_idp->stack + 1); + if (offset) { + data = (unsigned long *)(mm_idp->stack + offset - STUB_DATA); + printk(UM_KERN_ERR "do_syscall_stub : ret = %ld, offset = %ld, " + "data = %p\n", ret, offset, data); + syscall = (unsigned long *)((unsigned long)data + data[0]); + printk(UM_KERN_ERR "do_syscall_stub: syscall %ld failed, " + "return value = 0x%lx, expected return value = 0x%lx\n", + syscall[0], ret, syscall[7]); + printk(UM_KERN_ERR " syscall parameters: " + "0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx\n", + syscall[1], syscall[2], syscall[3], + syscall[4], syscall[5], syscall[6]); + for (n = 1; n < data[0]/sizeof(long); n++) { + if (n == 1) + printk(UM_KERN_ERR " additional syscall " + "data:"); + if (n % 4 == 1) + printk("\n" UM_KERN_ERR " "); + printk(" 0x%lx", data[n]); + } + if (n > 1) + printk("\n"); + } + else ret = 0; + + *addr = check_init_stack(mm_idp, NULL); + + return ret; +} + +long run_syscall_stub(struct mm_id * mm_idp, int syscall, + unsigned long *args, long expected, void **addr, + int done) +{ + unsigned long *stack = check_init_stack(mm_idp, *addr); + + *stack += sizeof(long); + stack += *stack / sizeof(long); + + *stack++ = syscall; + *stack++ = args[0]; + *stack++ = args[1]; + *stack++ = args[2]; + *stack++ = args[3]; + *stack++ = args[4]; + *stack++ = args[5]; + *stack++ = expected; + *stack = 0; + + if (!done && ((((unsigned long) stack) & ~UM_KERN_PAGE_MASK) < + UM_KERN_PAGE_SIZE - 10 * sizeof(long))) { + *addr = stack; + return 0; + } + + return do_syscall_stub(mm_idp, addr); +} + +long syscall_stub_data(struct mm_id * mm_idp, + unsigned long *data, int data_count, + void **addr, void **stub_addr) +{ + unsigned long *stack; + int ret = 0; + + /* + * If *addr still is uninitialized, it *must* contain NULL. + * Thus in this case do_syscall_stub correctly won't be called. + */ + if ((((unsigned long) *addr) & ~UM_KERN_PAGE_MASK) >= + UM_KERN_PAGE_SIZE - (10 + data_count) * sizeof(long)) { + ret = do_syscall_stub(mm_idp, addr); + /* in case of error, don't overwrite data on stack */ + if (ret) + return ret; + } + + stack = check_init_stack(mm_idp, *addr); + *addr = stack; + + *stack = data_count * sizeof(long); + + memcpy(stack + 1, data, data_count * sizeof(long)); + + *stub_addr = (void *)(((unsigned long)(stack + 1) & + ~UM_KERN_PAGE_MASK) + STUB_DATA); + + return 0; +} + +int map(struct mm_id * mm_idp, unsigned long virt, unsigned long len, int prot, + int phys_fd, unsigned long long offset, int done, void **data) +{ + int ret; + unsigned long args[] = { virt, len, prot, + MAP_SHARED | MAP_FIXED, phys_fd, + MMAP_OFFSET(offset) }; + + ret = run_syscall_stub(mm_idp, STUB_MMAP_NR, args, virt, + data, done); + + return ret; +} + +int unmap(struct mm_id * mm_idp, unsigned long addr, unsigned long len, + int done, void **data) +{ + int ret; + unsigned long args[] = { (unsigned long) addr, len, 0, 0, 0, + 0 }; + + ret = run_syscall_stub(mm_idp, __NR_munmap, args, 0, + data, done); + + return ret; +} + +int protect(struct mm_id * mm_idp, unsigned long addr, unsigned long len, + unsigned int prot, int done, void **data) +{ + int ret; + unsigned long args[] = { addr, len, prot, 0, 0, 0 }; + + ret = run_syscall_stub(mm_idp, __NR_mprotect, args, 0, + data, done); + + return ret; +} |