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| author |   Nadav Amit <namit@vmware.com> | 2019-04-25 17:11:22 -0700 |
|---|---|---|
| committer |   Ingo Molnar <mingo@kernel.org> | 2019-04-30 12:37:49 +0200 |
| commit | 1fd8de46d01d95f875c12684a6a03559831e8b4c (patch) | |
| tree | f5f324697b3b4eb8784bf6d55b82cf13f87b4c02 /arch/x86/kernel/jump_label.c | |
| parent | bpf: Fail bpf_probe_write_user() while mm is switched (diff) | |
| download | linux-dev-1fd8de46d01d95f875c12684a6a03559831e8b4c.tar.xz linux-dev-1fd8de46d01d95f875c12684a6a03559831e8b4c.zip | |
x86/jump_label: Use text_poke_early() during early init
There is no apparent reason not to use text_poke_early() during
early-init, since no patching of code that might be on the stack is done
and only a single core is running.
This is required for the next patches that would set a temporary mm for
text poking, and this mm is only initialized after some static-keys are
enabled/disabled.
Signed-off-by: Nadav Amit <namit@vmware.com>
Signed-off-by: Rick Edgecombe <rick.p.edgecombe@intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: <akpm@linux-foundation.org>
Cc: <ard.biesheuvel@linaro.org>
Cc: <deneen.t.dock@intel.com>
Cc: <kernel-hardening@lists.openwall.com>
Cc: <kristen@linux.intel.com>
Cc: <linux_dti@icloud.com>
Cc: <will.deacon@arm.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Rik van Riel <riel@surriel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20190426001143.4983-3-namit@vmware.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to '')
| -rw-r--r-- | arch/x86/kernel/jump_label.c | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/arch/x86/kernel/jump_label.c b/arch/x86/kernel/jump_label.c index f99bd26bd3f1..e7d8c636b228 100644 --- a/arch/x86/kernel/jump_label.c +++ b/arch/x86/kernel/jump_label.c @@ -50,7 +50,12 @@ static void __ref __jump_label_transform(struct jump_entry *entry, jmp.offset = jump_entry_target(entry) - (jump_entry_code(entry) + JUMP_LABEL_NOP_SIZE); - if (early_boot_irqs_disabled) + /* + * As long as only a single processor is running and the code is still + * not marked as RO, text_poke_early() can be used; Checking that + * system_state is SYSTEM_BOOTING guarantees it. + */ + if (system_state == SYSTEM_BOOTING) poker = text_poke_early; if (type == JUMP_LABEL_JMP) { |