Messages in this thread Patch in this message | | | Date | Sun, 26 Apr 2020 06:47:40 -0000 | From | "tip-bot2 for Josh Poimboeuf" <> | Subject | [tip: x86/urgent] x86/unwind/orc: Prevent unwinding before ORC initialization |
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The following commit has been merged into the x86/urgent branch of tip:
Commit-ID: 98d0c8ebf77e0ba7c54a9ae05ea588f0e9e3f46e Gitweb: https://git.kernel.org/tip/98d0c8ebf77e0ba7c54a9ae05ea588f0e9e3f46e Author: Josh Poimboeuf <jpoimboe@redhat.com> AuthorDate: Sat, 25 Apr 2020 05:03:08 -05:00 Committer: Ingo Molnar <mingo@kernel.org> CommitterDate: Sat, 25 Apr 2020 12:22:29 +02:00
x86/unwind/orc: Prevent unwinding before ORC initialization
If the unwinder is called before the ORC data has been initialized, orc_find() returns NULL, and it tries to fall back to using frame pointers. This can cause some unexpected warnings during boot.
Move the 'orc_init' check from orc_find() to __unwind_init(), so that it doesn't even try to unwind from an uninitialized state.
Fixes: ee9f8fce9964 ("x86/unwind: Add the ORC unwinder") Reviewed-by: Miroslav Benes <mbenes@suse.cz> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Dave Jones <dsj@fb.com> Cc: Jann Horn <jannh@google.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Link: https://lore.kernel.org/r/069d1499ad606d85532eb32ce39b2441679667d5.1587808742.git.jpoimboe@redhat.com --- arch/x86/kernel/unwind_orc.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/arch/x86/kernel/unwind_orc.c b/arch/x86/kernel/unwind_orc.c index e9f5a20..cb11567 100644 --- a/arch/x86/kernel/unwind_orc.c +++ b/arch/x86/kernel/unwind_orc.c @@ -148,9 +148,6 @@ static struct orc_entry *orc_find(unsigned long ip) { static struct orc_entry *orc; - if (!orc_init) - return NULL; - if (ip == 0) return &null_orc_entry; @@ -591,6 +588,9 @@ EXPORT_SYMBOL_GPL(unwind_next_frame); void __unwind_start(struct unwind_state *state, struct task_struct *task, struct pt_regs *regs, unsigned long *first_frame) { + if (!orc_init) + goto done; + memset(state, 0, sizeof(*state)); state->task = task;
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