diff options
Diffstat (limited to 'arch/um/kernel/ptrace.c')
| -rw-r--r-- | arch/um/kernel/ptrace.c | 209 |
1 files changed, 209 insertions, 0 deletions
diff --git a/arch/um/kernel/ptrace.c b/arch/um/kernel/ptrace.c new file mode 100644 index 00000000..06b19039 --- /dev/null +++ b/arch/um/kernel/ptrace.c @@ -0,0 +1,209 @@ +/* + * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com) + * Licensed under the GPL + */ + +#include "linux/audit.h" +#include "linux/ptrace.h" +#include "linux/sched.h" +#include "asm/uaccess.h" +#include "skas_ptrace.h" + + + +void user_enable_single_step(struct task_struct *child) +{ + child->ptrace |= PT_DTRACE; + child->thread.singlestep_syscall = 0; + +#ifdef SUBARCH_SET_SINGLESTEPPING + SUBARCH_SET_SINGLESTEPPING(child, 1); +#endif +} + +void user_disable_single_step(struct task_struct *child) +{ + child->ptrace &= ~PT_DTRACE; + child->thread.singlestep_syscall = 0; + +#ifdef SUBARCH_SET_SINGLESTEPPING + SUBARCH_SET_SINGLESTEPPING(child, 0); +#endif +} + +/* + * Called by kernel/ptrace.c when detaching.. + */ +void ptrace_disable(struct task_struct *child) +{ + user_disable_single_step(child); +} + +extern int peek_user(struct task_struct * child, long addr, long data); +extern int poke_user(struct task_struct * child, long addr, long data); + +long arch_ptrace(struct task_struct *child, long request, + unsigned long addr, unsigned long data) +{ + int i, ret; + unsigned long __user *p = (void __user *)data; + void __user *vp = p; + + switch (request) { + /* read the word at location addr in the USER area. */ + case PTRACE_PEEKUSR: + ret = peek_user(child, addr, data); + break; + + /* write the word at location addr in the USER area */ + case PTRACE_POKEUSR: + ret = poke_user(child, addr, data); + break; + + case PTRACE_SYSEMU: + case PTRACE_SYSEMU_SINGLESTEP: + ret = -EIO; + break; + +#ifdef PTRACE_GETREGS + case PTRACE_GETREGS: { /* Get all gp regs from the child. */ + if (!access_ok(VERIFY_WRITE, p, MAX_REG_OFFSET)) { + ret = -EIO; + break; + } + for ( i = 0; i < MAX_REG_OFFSET; i += sizeof(long) ) { + __put_user(getreg(child, i), p); + p++; + } + ret = 0; + break; + } +#endif +#ifdef PTRACE_SETREGS + case PTRACE_SETREGS: { /* Set all gp regs in the child. */ + unsigned long tmp = 0; + if (!access_ok(VERIFY_READ, p, MAX_REG_OFFSET)) { + ret = -EIO; + break; + } + for ( i = 0; i < MAX_REG_OFFSET; i += sizeof(long) ) { + __get_user(tmp, p); + putreg(child, i, tmp); + p++; + } + ret = 0; + break; + } +#endif + case PTRACE_GET_THREAD_AREA: + ret = ptrace_get_thread_area(child, addr, vp); + break; + + case PTRACE_SET_THREAD_AREA: + ret = ptrace_set_thread_area(child, addr, vp); + break; + + case PTRACE_FAULTINFO: { + /* + * Take the info from thread->arch->faultinfo, + * but transfer max. sizeof(struct ptrace_faultinfo). + * On i386, ptrace_faultinfo is smaller! + */ + ret = copy_to_user(p, &child->thread.arch.faultinfo, + sizeof(struct ptrace_faultinfo)) ? + -EIO : 0; + break; + } + +#ifdef PTRACE_LDT + case PTRACE_LDT: { + struct ptrace_ldt ldt; + + if (copy_from_user(&ldt, p, sizeof(ldt))) { + ret = -EIO; + break; + } + + /* + * This one is confusing, so just punt and return -EIO for + * now + */ + ret = -EIO; + break; + } +#endif + default: + ret = ptrace_request(child, request, addr, data); + if (ret == -EIO) + ret = subarch_ptrace(child, request, addr, data); + break; + } + + return ret; +} + +static void send_sigtrap(struct task_struct *tsk, struct uml_pt_regs *regs, + int error_code) +{ + struct siginfo info; + + memset(&info, 0, sizeof(info)); + info.si_signo = SIGTRAP; + info.si_code = TRAP_BRKPT; + + /* User-mode eip? */ + info.si_addr = UPT_IS_USER(regs) ? (void __user *) UPT_IP(regs) : NULL; + + /* Send us the fake SIGTRAP */ + force_sig_info(SIGTRAP, &info, tsk); +} + +/* + * XXX Check PT_DTRACE vs TIF_SINGLESTEP for singlestepping check and + * PT_PTRACED vs TIF_SYSCALL_TRACE for syscall tracing check + */ +void syscall_trace(struct uml_pt_regs *regs, int entryexit) +{ + int is_singlestep = (current->ptrace & PT_DTRACE) && entryexit; + int tracesysgood; + + if (!entryexit) + audit_syscall_entry(HOST_AUDIT_ARCH, + UPT_SYSCALL_NR(regs), + UPT_SYSCALL_ARG1(regs), + UPT_SYSCALL_ARG2(regs), + UPT_SYSCALL_ARG3(regs), + UPT_SYSCALL_ARG4(regs)); + else + audit_syscall_exit(regs); + + /* Fake a debug trap */ + if (is_singlestep) + send_sigtrap(current, regs, 0); + + if (!test_thread_flag(TIF_SYSCALL_TRACE)) + return; + + if (!(current->ptrace & PT_PTRACED)) + return; + + /* + * the 0x80 provides a way for the tracing parent to distinguish + * between a syscall stop and SIGTRAP delivery + */ + tracesysgood = (current->ptrace & PT_TRACESYSGOOD); + ptrace_notify(SIGTRAP | (tracesysgood ? 0x80 : 0)); + + if (entryexit) /* force do_signal() --> is_syscall() */ + set_thread_flag(TIF_SIGPENDING); + + /* + * this isn't the same as continuing with a signal, but it will do + * for normal use. strace only continues with a signal if the + * stopping signal is not SIGTRAP. -brl + */ + if (current->exit_code) { + send_sig(current->exit_code, current, 1); + current->exit_code = 0; + } +} |