path: root/tools
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authorFrancis Deslauriers <francis.deslauriers@efficios.com>2018-03-08 22:18:12 -0500
committerIngo Molnar <mingo@kernel.org>2018-03-09 09:58:36 +0100
commitc07a8f8b08ba683ea24f3ac9159f37ae94daf47f (patch)
tree95e555c78554c98bba7955279d585cc687ee4220 /tools
parentc5b679f5c9e3851ee118d95961def374bb3b4ce6 (diff)
x86/kprobes: Fix kernel crash when probing .entry_trampoline code
Disable the kprobe probing of the entry trampoline: .entry_trampoline is a code area that is used to ensure page table isolation between userspace and kernelspace. At the beginning of the execution of the trampoline, we load the kernel's CR3 register. This has the effect of enabling the translation of the kernel virtual addresses to physical addresses. Before this happens most kernel addresses can not be translated because the running process' CR3 is still used. If a kprobe is placed on the trampoline code before that change of the CR3 register happens the kernel crashes because int3 handling pages are not accessible. To fix this, add the .entry_trampoline section to the kprobe blacklist to prohibit the probing of code before all the kernel pages are accessible. Signed-off-by: Francis Deslauriers <francis.deslauriers@efficios.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: mathieu.desnoyers@efficios.com Cc: mhiramat@kernel.org Link: http://lkml.kernel.org/r/1520565492-4637-2-git-send-email-francis.deslauriers@efficios.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'tools')
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