96d4f267e4
Nobody has actually used the type (VERIFY_READ vs VERIFY_WRITE) argument
of the user address range verification function since we got rid of the
old racy i386-only code to walk page tables by hand.
It existed because the original 80386 would not honor the write protect
bit when in kernel mode, so you had to do COW by hand before doing any
user access. But we haven't supported that in a long time, and these
days the 'type' argument is a purely historical artifact.
A discussion about extending 'user_access_begin()' to do the range
checking resulted this patch, because there is no way we're going to
move the old VERIFY_xyz interface to that model. And it's best done at
the end of the merge window when I've done most of my merges, so let's
just get this done once and for all.
This patch was mostly done with a sed-script, with manual fix-ups for
the cases that weren't of the trivial 'access_ok(VERIFY_xyz' form.
There were a couple of notable cases:
- csky still had the old "verify_area()" name as an alias.
- the iter_iov code had magical hardcoded knowledge of the actual
values of VERIFY_{READ,WRITE} (not that they mattered, since nothing
really used it)
- microblaze used the type argument for a debug printout
but other than those oddities this should be a total no-op patch.
I tried to fix up all architectures, did fairly extensive grepping for
access_ok() uses, and the changes are trivial, but I may have missed
something. Any missed conversion should be trivially fixable, though.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
160 lines
3.5 KiB
C
160 lines
3.5 KiB
C
/*
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* Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
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* Licensed under the GPL
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*/
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#include <linux/audit.h>
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#include <linux/ptrace.h>
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#include <linux/sched.h>
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#include <linux/tracehook.h>
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#include <linux/uaccess.h>
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#include <asm/ptrace-abi.h>
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void user_enable_single_step(struct task_struct *child)
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{
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child->ptrace |= PT_DTRACE;
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child->thread.singlestep_syscall = 0;
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#ifdef SUBARCH_SET_SINGLESTEPPING
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SUBARCH_SET_SINGLESTEPPING(child, 1);
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#endif
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}
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void user_disable_single_step(struct task_struct *child)
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{
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child->ptrace &= ~PT_DTRACE;
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child->thread.singlestep_syscall = 0;
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#ifdef SUBARCH_SET_SINGLESTEPPING
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SUBARCH_SET_SINGLESTEPPING(child, 0);
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#endif
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}
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/*
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* Called by kernel/ptrace.c when detaching..
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*/
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void ptrace_disable(struct task_struct *child)
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{
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user_disable_single_step(child);
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}
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extern int peek_user(struct task_struct * child, long addr, long data);
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extern int poke_user(struct task_struct * child, long addr, long data);
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long arch_ptrace(struct task_struct *child, long request,
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unsigned long addr, unsigned long data)
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{
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int i, ret;
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unsigned long __user *p = (void __user *)data;
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void __user *vp = p;
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switch (request) {
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/* read the word at location addr in the USER area. */
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case PTRACE_PEEKUSR:
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ret = peek_user(child, addr, data);
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break;
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/* write the word at location addr in the USER area */
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case PTRACE_POKEUSR:
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ret = poke_user(child, addr, data);
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break;
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case PTRACE_SYSEMU:
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case PTRACE_SYSEMU_SINGLESTEP:
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ret = -EIO;
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break;
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#ifdef PTRACE_GETREGS
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case PTRACE_GETREGS: { /* Get all gp regs from the child. */
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if (!access_ok(p, MAX_REG_OFFSET)) {
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ret = -EIO;
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break;
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}
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for ( i = 0; i < MAX_REG_OFFSET; i += sizeof(long) ) {
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__put_user(getreg(child, i), p);
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p++;
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}
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ret = 0;
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break;
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}
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#endif
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#ifdef PTRACE_SETREGS
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case PTRACE_SETREGS: { /* Set all gp regs in the child. */
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unsigned long tmp = 0;
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if (!access_ok(p, MAX_REG_OFFSET)) {
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ret = -EIO;
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break;
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}
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for ( i = 0; i < MAX_REG_OFFSET; i += sizeof(long) ) {
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__get_user(tmp, p);
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putreg(child, i, tmp);
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p++;
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}
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ret = 0;
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break;
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}
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#endif
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case PTRACE_GET_THREAD_AREA:
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ret = ptrace_get_thread_area(child, addr, vp);
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break;
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case PTRACE_SET_THREAD_AREA:
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ret = ptrace_set_thread_area(child, addr, vp);
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break;
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default:
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ret = ptrace_request(child, request, addr, data);
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if (ret == -EIO)
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ret = subarch_ptrace(child, request, addr, data);
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break;
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}
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return ret;
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}
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static void send_sigtrap(struct task_struct *tsk, struct uml_pt_regs *regs,
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int error_code)
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{
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/* Send us the fake SIGTRAP */
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force_sig_fault(SIGTRAP, TRAP_BRKPT,
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/* User-mode eip? */
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UPT_IS_USER(regs) ? (void __user *) UPT_IP(regs) : NULL, tsk);
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}
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/*
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* XXX Check PT_DTRACE vs TIF_SINGLESTEP for singlestepping check and
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* PT_PTRACED vs TIF_SYSCALL_TRACE for syscall tracing check
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*/
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int syscall_trace_enter(struct pt_regs *regs)
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{
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audit_syscall_entry(UPT_SYSCALL_NR(®s->regs),
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UPT_SYSCALL_ARG1(®s->regs),
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UPT_SYSCALL_ARG2(®s->regs),
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UPT_SYSCALL_ARG3(®s->regs),
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UPT_SYSCALL_ARG4(®s->regs));
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if (!test_thread_flag(TIF_SYSCALL_TRACE))
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return 0;
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return tracehook_report_syscall_entry(regs);
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}
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void syscall_trace_leave(struct pt_regs *regs)
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{
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int ptraced = current->ptrace;
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audit_syscall_exit(regs);
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/* Fake a debug trap */
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if (ptraced & PT_DTRACE)
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send_sigtrap(current, ®s->regs, 0);
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if (!test_thread_flag(TIF_SYSCALL_TRACE))
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return;
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tracehook_report_syscall_exit(regs, 0);
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/* force do_signal() --> is_syscall() */
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if (ptraced & PT_PTRACED)
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set_thread_flag(TIF_SIGPENDING);
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}
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