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| author |   Jiri Kosina <jkosina@suse.cz> | 2018-08-28 08:55:14 +0200 |
|---|---|---|
| committer |   Thomas Gleixner <tglx@linutronix.de> | 2018-08-30 13:02:30 +0200 |
| commit | 9222f606506c5f8ca2c8b8c939d59ed3e6ac4148 (patch) | |
| tree | fd08042dd7d4ce57105b764be0c5fc0082f7a3d4 /arch | |
| parent | x86/entry/64: Wipe KASAN stack shadow before rewind_stack_do_exit() (diff) | |
| download | linux-dev-9222f606506c5f8ca2c8b8c939d59ed3e6ac4148.tar.xz linux-dev-9222f606506c5f8ca2c8b8c939d59ed3e6ac4148.zip | |
x86/alternatives: Lockdep-enforce text_mutex in text_poke*()
text_poke() and text_poke_bp() must be called with text_mutex held.
Put proper lockdep anotation in place instead of just mentioning the
requirement in a comment.
Reported-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Andy Lutomirski <luto@kernel.org>
Link: https://lkml.kernel.org/r/nycvar.YFH.7.76.1808280853520.25787@cbobk.fhfr.pm
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/x86/kernel/alternative.c | 9 |
1 files changed, 5 insertions, 4 deletions
diff --git a/arch/x86/kernel/alternative.c b/arch/x86/kernel/alternative.c index 014f214da581..b9d5e7c9ef43 100644 --- a/arch/x86/kernel/alternative.c +++ b/arch/x86/kernel/alternative.c @@ -684,8 +684,6 @@ void *__init_or_module text_poke_early(void *addr, const void *opcode, * It means the size must be writable atomically and the address must be aligned * in a way that permits an atomic write. It also makes sure we fit on a single * page. - * - * Note: Must be called under text_mutex. */ void *text_poke(void *addr, const void *opcode, size_t len) { @@ -700,6 +698,8 @@ void *text_poke(void *addr, const void *opcode, size_t len) */ BUG_ON(!after_bootmem); + lockdep_assert_held(&text_mutex); + if (!core_kernel_text((unsigned long)addr)) { pages[0] = vmalloc_to_page(addr); pages[1] = vmalloc_to_page(addr + PAGE_SIZE); @@ -782,8 +782,6 @@ int poke_int3_handler(struct pt_regs *regs) * - replace the first byte (int3) by the first byte of * replacing opcode * - sync cores - * - * Note: must be called under text_mutex. */ void *text_poke_bp(void *addr, const void *opcode, size_t len, void *handler) { @@ -792,6 +790,9 @@ void *text_poke_bp(void *addr, const void *opcode, size_t len, void *handler) bp_int3_handler = handler; bp_int3_addr = (u8 *)addr + sizeof(int3); bp_patching_in_progress = true; + + lockdep_assert_held(&text_mutex); + /* * Corresponding read barrier in int3 notifier for making sure the * in_progress and handler are correctly ordered wrt. patching. |