diff options
| author | Tony Luck <tony.luck@intel.com> | 2016-02-17 10:20:12 -0800 |
|---|---|---|
| committer | Sasha Levin <alexander.levin@verizon.com> | 2016-10-30 14:15:18 -0400 |
| commit | 7ea3d2e9c6aa73bc07d537ab4574d18bcfe2f680 (patch) | |
| tree | 7ad294894bae5613a0be2673889bea53ce49fe04 /arch/x86/kernel | |
| parent | 9ca365c0c8bdd8552ec064f0e696600cf7ea66dd (diff) | |
x86/mm: Expand the exception table logic to allow new handling options
[ Upstream commit 548acf19234dbda5a52d5a8e7e205af46e9da840 ]
Huge amounts of help from Andy Lutomirski and Borislav Petkov to
produce this. Andy provided the inspiration to add classes to the
exception table with a clever bit-squeezing trick, Boris pointed
out how much cleaner it would all be if we just had a new field.
Linus Torvalds blessed the expansion with:
' I'd rather not be clever in order to save just a tiny amount of space
in the exception table, which isn't really criticial for anybody. '
The third field is another relative function pointer, this one to a
handler that executes the actions.
We start out with three handlers:
1: Legacy - just jumps the to fixup IP
2: Fault - provide the trap number in %ax to the fixup code
3: Cleaned up legacy for the uaccess error hack
Signed-off-by: Tony Luck <tony.luck@intel.com>
Reviewed-by: Borislav Petkov <bp@suse.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/f6af78fcbd348cf4939875cfda9c19689b5e50b8.1455732970.git.tony.luck@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Diffstat (limited to 'arch/x86/kernel')
| -rw-r--r-- | arch/x86/kernel/kprobes/core.c | 2 | ||||
| -rw-r--r-- | arch/x86/kernel/traps.c | 6 |
2 files changed, 4 insertions, 4 deletions
diff --git a/arch/x86/kernel/kprobes/core.c b/arch/x86/kernel/kprobes/core.c index 023c442c33bb..e1d1f6cbaf11 100644 --- a/arch/x86/kernel/kprobes/core.c +++ b/arch/x86/kernel/kprobes/core.c @@ -1000,7 +1000,7 @@ int kprobe_fault_handler(struct pt_regs *regs, int trapnr) * In case the user-specified fault handler returned * zero, try to fix up. */ - if (fixup_exception(regs)) + if (fixup_exception(regs, trapnr)) return 1; /* diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c index 324ab5247687..020248f2cec4 100644 --- a/arch/x86/kernel/traps.c +++ b/arch/x86/kernel/traps.c @@ -208,7 +208,7 @@ do_trap_no_signal(struct task_struct *tsk, int trapnr, char *str, } if (!user_mode(regs)) { - if (!fixup_exception(regs)) { + if (!fixup_exception(regs, trapnr)) { tsk->thread.error_code = error_code; tsk->thread.trap_nr = trapnr; die(str, regs, error_code); @@ -469,7 +469,7 @@ do_general_protection(struct pt_regs *regs, long error_code) tsk = current; if (!user_mode(regs)) { - if (fixup_exception(regs)) + if (fixup_exception(regs, X86_TRAP_GP)) goto exit; tsk->thread.error_code = error_code; @@ -720,7 +720,7 @@ static void math_error(struct pt_regs *regs, int error_code, int trapnr) if (!user_mode(regs)) { - if (!fixup_exception(regs)) { + if (!fixup_exception(regs, trapnr)) { task->thread.error_code = error_code; task->thread.trap_nr = trapnr; die(str, regs, error_code); |