diff options
| author | Oleg Nesterov <oleg@redhat.com> | 2012-09-03 16:05:10 +0200 |
|---|---|---|
| committer | Oleg Nesterov <oleg@redhat.com> | 2012-09-15 17:37:31 +0200 |
| commit | 3a4664aa8362d9fa9110828f55afa9f9fcd7e484 (patch) | |
| tree | f2a4314a4e71b9273a15e7816197b38505c44092 /arch/x86/include/asm/uprobes.h | |
| parent | 9bd1190a11c9d2c59d35cb999b8d170ad52aab5f (diff) | |
uprobes/x86: Xol should send SIGTRAP if X86_EFLAGS_TF was set
arch_uprobe_disable_step() correctly preserves X86_EFLAGS_TF and
returns to user-mode. But this means the application gets SIGTRAP
only after the next insn.
This means that UPROBE_CLEAR_TF logic is not really right. _enable
should only record the state of X86_EFLAGS_TF, and _disable should
check it separately from UPROBE_FIX_SETF.
Remove arch_uprobe_task->restore_flags, add ->saved_tf instead, and
change enable/disable accordingly. This assumes that the probed insn
was not trapped, see the next patch.
arch_uprobe_skip_sstep() logic has the same problem, change it to
check X86_EFLAGS_TF and send SIGTRAP as well. We will cleanup this
all after we fold enable/disable_step into pre/post_hol hooks.
Note: send_sig(SIGTRAP) is not actually right, we need send_sigtrap().
But this needs more changes, handle_swbp() does the same and this is
equally wrong.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Diffstat (limited to 'arch/x86/include/asm/uprobes.h')
| -rw-r--r-- | arch/x86/include/asm/uprobes.h | 3 |
1 files changed, 1 insertions, 2 deletions
diff --git a/arch/x86/include/asm/uprobes.h b/arch/x86/include/asm/uprobes.h index cee58624cb3..d561ff5a3d4 100644 --- a/arch/x86/include/asm/uprobes.h +++ b/arch/x86/include/asm/uprobes.h @@ -46,8 +46,7 @@ struct arch_uprobe_task { #ifdef CONFIG_X86_64 unsigned long saved_scratch_register; #endif -#define UPROBE_CLEAR_TF (1 << 0) - unsigned int restore_flags; + unsigned int saved_tf; }; extern int arch_uprobe_analyze_insn(struct arch_uprobe *aup, struct mm_struct *mm, unsigned long addr); |