/* * 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; }