Commit-ID: 1fd8de46d01d95f875c12684a6a03559831e8b4c Gitweb: https://git.kernel.org/tip/1fd8de46d01d95f875c12684a6a03559831e8b4c Author: Nadav Amit <namit@xxxxxxxxxx> AuthorDate: Thu, 25 Apr 2019 17:11:22 -0700 Committer: Ingo Molnar <mingo@xxxxxxxxxx> CommitDate: Tue, 30 Apr 2019 12:37:49 +0200 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@xxxxxxxxxx> Signed-off-by: Rick Edgecombe <rick.p.edgecombe@xxxxxxxxx> Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx> Cc: <akpm@xxxxxxxxxxxxxxxxxxxx> Cc: <ard.biesheuvel@xxxxxxxxxx> Cc: <deneen.t.dock@xxxxxxxxx> Cc: <kernel-hardening@xxxxxxxxxxxxxxxxxx> Cc: <kristen@xxxxxxxxxxxxxxx> Cc: <linux_dti@xxxxxxxxxx> Cc: <will.deacon@xxxxxxx> Cc: Andy Lutomirski <luto@xxxxxxxxxx> Cc: Borislav Petkov <bp@xxxxxxxxx> Cc: Dave Hansen <dave.hansen@xxxxxxxxx> Cc: H. Peter Anvin <hpa@xxxxxxxxx> Cc: Kees Cook <keescook@xxxxxxxxxxxx> Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> Cc: Masami Hiramatsu <mhiramat@xxxxxxxxxx> Cc: Rik van Riel <riel@xxxxxxxxxxx> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Link: https://lkml.kernel.org/r/20190426001143.4983-3-namit@xxxxxxxxxx Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx> --- arch/x86/kernel/jump_label.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) 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) {
