perf/x86/hw_breakpoints: Disallow kernel breakpoints unless kprobe-safe

i/linux

Code on the kprobe blacklist doesn't want unexpected int3
exceptions. It probably doesn't want unexpected debug exceptions
either. Be safe: disallow breakpoints in nokprobes code.

On non-CONFIG_KPROBES kernels, there is no kprobe blacklist.  In
that case, disallow kernel breakpoints entirely.

It will be particularly important to keep hw breakpoints out of the
entry and NMI code once we move debug exceptions off the IST stack.

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/e14b152af99640448d895e3c2a8c2d5ee19a1325.1438312874.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

This commit is contained in:

Andy Lutomirski

2015-07-30 20:32:40 -07:00

committed by

Ingo Molnar

parent ae3f011fc2

commit e5779e8e12

3 changed files with 18 additions and 1 deletions

									
										kernel/kprobes.c
									
		+1
		-1
	
												View File
												
				@@ -1332,7 +1332,7 @@ bool __weak arch_within_kprobe_blacklist(unsigned long addr)

					       addr < (unsigned long)__kprobes_text_end;

				}

				static bool within_kprobe_blacklist(unsigned long addr)

				bool within_kprobe_blacklist(unsigned long addr)

				{

					struct kprobe_blacklist_entry *ent;