From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Tue, 30 Apr 2019 04:15:55 -0700 Sender: tip tree robot From: tip-bot for Nadav Amit Message-ID: In-Reply-To: <20190426001143.4983-3-namit@vmware.com> References: <20190426001143.4983-3-namit@vmware.com> Subject: [tip:x86/mm] x86/jump_label: Use text_poke_early() during early init MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline To: linux-tip-commits@vger.kernel.org Cc: riel@surriel.com, akpm@linux-foundation.org, kernel-hardening@lists.openwall.com, torvalds@linux-foundation.org, hpa@zytor.com, mingo@kernel.org, linux-kernel@vger.kernel.org, dave.hansen@intel.com, kristen@linux.intel.com, bp@alien8.de, tglx@linutronix.de, linux_dti@icloud.com, will.deacon@arm.com, keescook@chromium.org, deneen.t.dock@intel.com, namit@vmware.com, mhiramat@kernel.org, rick.p.edgecombe@intel.com, ard.biesheuvel@linaro.org, peterz@infradead.org, luto@kernel.org List-ID: Commit-ID: 1fd8de46d01d95f875c12684a6a03559831e8b4c Gitweb: https://git.kernel.org/tip/1fd8de46d01d95f875c12684a6a03559831e8b4c Author: Nadav Amit AuthorDate: Thu, 25 Apr 2019 17:11:22 -0700 Committer: Ingo Molnar 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 Signed-off-by: Rick Edgecombe Signed-off-by: Peter Zijlstra (Intel) Cc: Cc: Cc: Cc: Cc: Cc: Cc: Cc: Andy Lutomirski Cc: Borislav Petkov Cc: Dave Hansen Cc: H. Peter Anvin Cc: Kees Cook Cc: Linus Torvalds Cc: Masami Hiramatsu Cc: Rik van Riel Cc: Thomas Gleixner Link: https://lkml.kernel.org/r/20190426001143.4983-3-namit@vmware.com Signed-off-by: Ingo Molnar --- 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) {