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| author | Oleg Nesterov <oleg@redhat.com> | 2012-09-03 16:05:10 +0200 |
|---|---|---|
| committer | Anton Arapov <anton@redhat.com> | 2012-10-29 11:23:46 +0100 |
| commit | 65f4fb9715827630e63934868e53781ea82ea0e1 (patch) | |
| tree | 162c51a0a2316fea3cf1a6e33516f427b88e3fa7 /arch/x86/include/asm/uprobes.h | |
| parent | 8b5e7bd2a7d4aff576d50051d9da139a6cf67de3 (diff) | |
| download | kernel-uprobes-65f4fb9715827630e63934868e53781ea82ea0e1.tar.gz kernel-uprobes-65f4fb9715827630e63934868e53781ea82ea0e1.tar.xz kernel-uprobes-65f4fb9715827630e63934868e53781ea82ea0e1.zip | |
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); |