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| author |   Josh Poimboeuf <jpoimboe@redhat.com> | 2020-04-25 05:03:08 -0500 |
|---|---|---|
| committer |   Ingo Molnar <mingo@kernel.org> | 2020-04-25 12:22:29 +0200 |
| commit | 98d0c8ebf77e0ba7c54a9ae05ea588f0e9e3f46e (patch) | |
| tree | 3d3bfb9a7258948eb9af32f6a0388a6fe27fe4f2 /arch | |
| parent | x86/unwind/orc: Don't skip the first frame for inactive tasks (diff) | |
| download | linux-dev-98d0c8ebf77e0ba7c54a9ae05ea588f0e9e3f46e.tar.xz linux-dev-98d0c8ebf77e0ba7c54a9ae05ea588f0e9e3f46e.zip | |
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
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/x86/kernel/unwind_orc.c | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/arch/x86/kernel/unwind_orc.c b/arch/x86/kernel/unwind_orc.c index e9f5a20c69c6..cb11567361cc 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; |