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author | Oleg Nesterov <oleg@redhat.com> | 2014-05-12 20:24:45 +0400 |
---|---|---|
committer | Oleg Nesterov <oleg@redhat.com> | 2014-05-14 15:57:28 +0400 |
commit | b02ef20a9fba08948e643d3eec0efadf1da01a44 (patch) | |
tree | d0db097668940dce698fec8b00d228cd29c1dee0 /include/linux/uprobes.h | |
parent | 0eb14833d5b1ea1accfeffb71be5de5929f85da9 (diff) | |
download | linux-b02ef20a9fba08948e643d3eec0efadf1da01a44.tar.xz |
uprobes/x86: Fix the wrong ->si_addr when xol triggers a trap
If the probed insn triggers a trap, ->si_addr = regs->ip is technically
correct, but this is not what the signal handler wants; we need to pass
the address of the probed insn, not the address of xol slot.
Add the new arch-agnostic helper, uprobe_get_trap_addr(), and change
fill_trap_info() and math_error() to use it. !CONFIG_UPROBES case in
uprobes.h uses a macro to avoid include hell and ensure that it can be
compiled even if an architecture doesn't define instruction_pointer().
Test-case:
#include <signal.h>
#include <stdio.h>
#include <unistd.h>
extern void probe_div(void);
void sigh(int sig, siginfo_t *info, void *c)
{
int passed = (info->si_addr == probe_div);
printf(passed ? "PASS\n" : "FAIL\n");
_exit(!passed);
}
int main(void)
{
struct sigaction sa = {
.sa_sigaction = sigh,
.sa_flags = SA_SIGINFO,
};
sigaction(SIGFPE, &sa, NULL);
asm (
"xor %ecx,%ecx\n"
".globl probe_div; probe_div:\n"
"idiv %ecx\n"
);
return 0;
}
it fails if probe_div() is probed.
Note: show_unhandled_signals users should probably use this helper too,
but we need to cleanup them first.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Reviewed-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Diffstat (limited to 'include/linux/uprobes.h')
-rw-r--r-- | include/linux/uprobes.h | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/include/linux/uprobes.h b/include/linux/uprobes.h index edff2b97b864..88c3b7e8b384 100644 --- a/include/linux/uprobes.h +++ b/include/linux/uprobes.h @@ -102,6 +102,7 @@ extern int __weak set_orig_insn(struct arch_uprobe *aup, struct mm_struct *mm, u extern bool __weak is_swbp_insn(uprobe_opcode_t *insn); extern bool __weak is_trap_insn(uprobe_opcode_t *insn); extern unsigned long __weak uprobe_get_swbp_addr(struct pt_regs *regs); +extern unsigned long uprobe_get_trap_addr(struct pt_regs *regs); extern int uprobe_write_opcode(struct mm_struct *mm, unsigned long vaddr, uprobe_opcode_t); extern int uprobe_register(struct inode *inode, loff_t offset, struct uprobe_consumer *uc); extern int uprobe_apply(struct inode *inode, loff_t offset, struct uprobe_consumer *uc, bool); @@ -130,6 +131,9 @@ extern bool __weak arch_uprobe_ignore(struct arch_uprobe *aup, struct pt_regs *r #else /* !CONFIG_UPROBES */ struct uprobes_state { }; + +#define uprobe_get_trap_addr(regs) instruction_pointer(regs) + static inline int uprobe_register(struct inode *inode, loff_t offset, struct uprobe_consumer *uc) { |