diff options
| author | Masami Hiramatsu <mhiramat@redhat.com> | 2009-03-23 10:14:52 -0400 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2009-03-25 18:53:29 +0100 |
| commit | fee039a1d05c6e0f71b0fe270d847742a02d56c4 (patch) | |
| tree | 8a876f852588e2ff4219ab29de4586b8a40556f9 /arch/x86/kernel/kprobes.c | |
| parent | a524446fe82f7f38738403a5a080c4910af86a61 (diff) | |
x86: kretprobe-booster interrupt emulation code fix
Fix interrupt emulation code in kretprobe-booster according to
pt_regs update (es/ds change and gs adding).
This issue has been reported on systemtap-bugzilla:
http://sources.redhat.com/bugzilla/show_bug.cgi?id=9965
| On a -tip kernel on x86_32, kretprobe_example (from samples) triggers the
| following backtrace when its retprobing a class of functions that cause a
| copy_from/to_user().
|
| BUG: sleeping function called from invalid context at mm/memory.c:3196
| in_atomic(): 0, irqs_disabled(): 1, pid: 2286, name: cat
Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com>
Acked-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Tested-by: Bharata B Rao <bharata@linux.vnet.ibm.com>
Cc: systemtap-ml <systemtap@sources.redhat.com>
LKML-Reference: <49C7995C.2010601@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'arch/x86/kernel/kprobes.c')
| -rw-r--r-- | arch/x86/kernel/kprobes.c | 17 |
1 files changed, 9 insertions, 8 deletions
diff --git a/arch/x86/kernel/kprobes.c b/arch/x86/kernel/kprobes.c index 4558dd3918c..759095d53a0 100644 --- a/arch/x86/kernel/kprobes.c +++ b/arch/x86/kernel/kprobes.c @@ -638,13 +638,13 @@ static void __used __kprobes kretprobe_trampoline_holder(void) #else " pushf\n" /* - * Skip cs, ip, orig_ax. + * Skip cs, ip, orig_ax and gs. * trampoline_handler() will plug in these values */ - " subl $12, %esp\n" + " subl $16, %esp\n" " pushl %fs\n" - " pushl %ds\n" " pushl %es\n" + " pushl %ds\n" " pushl %eax\n" " pushl %ebp\n" " pushl %edi\n" @@ -655,10 +655,10 @@ static void __used __kprobes kretprobe_trampoline_holder(void) " movl %esp, %eax\n" " call trampoline_handler\n" /* Move flags to cs */ - " movl 52(%esp), %edx\n" - " movl %edx, 48(%esp)\n" + " movl 56(%esp), %edx\n" + " movl %edx, 52(%esp)\n" /* Replace saved flags with true return address. */ - " movl %eax, 52(%esp)\n" + " movl %eax, 56(%esp)\n" " popl %ebx\n" " popl %ecx\n" " popl %edx\n" @@ -666,8 +666,8 @@ static void __used __kprobes kretprobe_trampoline_holder(void) " popl %edi\n" " popl %ebp\n" " popl %eax\n" - /* Skip ip, orig_ax, es, ds, fs */ - " addl $20, %esp\n" + /* Skip ds, es, fs, gs, orig_ax and ip */ + " addl $24, %esp\n" " popf\n" #endif " ret\n"); @@ -691,6 +691,7 @@ static __used __kprobes void *trampoline_handler(struct pt_regs *regs) regs->cs = __KERNEL_CS; #else regs->cs = __KERNEL_CS | get_kernel_rpl(); + regs->gs = 0; #endif regs->ip = trampoline_address; regs->orig_ax = ~0UL; |