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| author |   Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> | 2014-06-14 06:47:12 +0000 |
|---|---|---|
| committer |   Ingo Molnar <mingo@kernel.org> | 2014-06-14 09:07:44 +0200 |
| commit | 4cdf77a828b056258f48a9f6078bd2f77d9704bb (patch) | |
| tree | 2a7a904eddc42c595c6a82204a9032b97d0c071f /arch/x86/kernel/traps.c | |
| parent | Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending (diff) | |
| download | linux-dev-4cdf77a828b056258f48a9f6078bd2f77d9704bb.tar.xz linux-dev-4cdf77a828b056258f48a9f6078bd2f77d9704bb.zip | |
x86/kprobes: Fix build errors and blacklist context_track_user
This essentially reverts commit:
ecd50f714c42 ("kprobes, x86: Call exception_enter after kprobes handled")
since it causes build errors with CONFIG_CONTEXT_TRACKING and
that has been made from misunderstandings;
context_track_user_*() don't involve much in interrupt context,
it just returns if in_interrupt() is true.
Instead of changing the do_debug/int3(), this just adds
context_track_user_*() to kprobes blacklist, since those are
still can be called right before kprobes handles int3 and debug
exceptions, and probing those will cause an infinite loop.
Reported-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: Kees Cook <keescook@chromium.org>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Seiji Aguchi <seiji.aguchi@hds.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Kees Cook <keescook@chromium.org>
Link: http://lkml.kernel.org/r/20140614064711.7865.45957.stgit@kbuild-fedora.novalocal
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86/kernel/traps.c')
| -rw-r--r-- | arch/x86/kernel/traps.c | 7 |
1 files changed, 4 insertions, 3 deletions
diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c index c6eb418c5627..0d0e922fafc1 100644 --- a/arch/x86/kernel/traps.c +++ b/arch/x86/kernel/traps.c @@ -343,6 +343,7 @@ dotraplinkage void notrace do_int3(struct pt_regs *regs, long error_code) if (poke_int3_handler(regs)) return; + prev_state = exception_enter(); #ifdef CONFIG_KGDB_LOW_LEVEL_TRAP if (kgdb_ll_trap(DIE_INT3, "int3", regs, error_code, X86_TRAP_BP, SIGTRAP) == NOTIFY_STOP) @@ -351,9 +352,8 @@ dotraplinkage void notrace do_int3(struct pt_regs *regs, long error_code) #ifdef CONFIG_KPROBES if (kprobe_int3_handler(regs)) - return; + goto exit; #endif - prev_state = exception_enter(); if (notify_die(DIE_INT3, "int3", regs, error_code, X86_TRAP_BP, SIGTRAP) == NOTIFY_STOP) @@ -433,6 +433,8 @@ dotraplinkage void do_debug(struct pt_regs *regs, long error_code) unsigned long dr6; int si_code; + prev_state = exception_enter(); + get_debugreg(dr6, 6); /* Filter out all the reserved bits which are preset to 1 */ @@ -465,7 +467,6 @@ dotraplinkage void do_debug(struct pt_regs *regs, long error_code) if (kprobe_debug_handler(regs)) goto exit; #endif - prev_state = exception_enter(); if (notify_die(DIE_DEBUG, "debug", regs, (long)&dr6, error_code, SIGTRAP) == NOTIFY_STOP) |