From: Rick Edgecombe <rick.p.edgecombe@intel.com>
To: Andy Lutomirski <luto@kernel.org>, Ingo Molnar <mingo@redhat.com>
Cc: linux-kernel@vger.kernel.org, x86@kernel.org, hpa@zytor.com,
Thomas Gleixner <tglx@linutronix.de>,
Borislav Petkov <bp@alien8.de>, Nadav Amit <nadav.amit@gmail.com>,
Dave Hansen <dave.hansen@linux.intel.com>,
Peter Zijlstra <peterz@infradead.org>,
linux_dti@icloud.com, linux-integrity@vger.kernel.org,
linux-security-module@vger.kernel.org, akpm@linux-foundation.org,
kernel-hardening@lists.openwall.com, linux-mm@kvack.org,
will.deacon@arm.com, ard.biesheuvel@linaro.org,
kristen@linux.intel.com, deneen.t.dock@intel.com,
Nadav Amit <namit@vmware.com>, Kees Cook <keescook@chromium.org>,
Dave Hansen <dave.hansen@intel.com>,
Masami Hiramatsu <mhiramat@kernel.org>,
Rick Edgecombe <rick.p.edgecombe@intel.com>
Subject: [PATCH v3 01/20] x86/jump_label: Use text_poke_early() during early init
Date: Thu, 21 Feb 2019 15:44:32 -0800 [thread overview]
Message-ID: <20190221234451.17632-2-rick.p.edgecombe@intel.com> (raw)
In-Reply-To: <20190221234451.17632-1-rick.p.edgecombe@intel.com>
From: Nadav Amit <namit@vmware.com>
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.
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Nadav Amit <namit@vmware.com>
Signed-off-by: Rick Edgecombe <rick.p.edgecombe@intel.com>
---
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) {
--
2.17.1
next prev parent reply other threads:[~2019-02-21 23:52 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-02-21 23:44 [PATCH v3 00/20] Merge text_poke fixes and executable lockdowns Rick Edgecombe
2019-02-21 23:44 ` Rick Edgecombe [this message]
2019-02-21 23:44 ` [PATCH v3 02/20] x86/mm: Introduce temporary mm structs Rick Edgecombe
2019-02-21 23:44 ` [PATCH v3 03/20] x86/mm: Save DRs when loading a temporary mm Rick Edgecombe
2019-02-22 0:07 ` Sean Christopherson
2019-02-22 0:17 ` Nadav Amit
2019-02-21 23:44 ` [PATCH v3 04/20] fork: Provide a function for copying init_mm Rick Edgecombe
2019-02-21 23:44 ` [PATCH v3 05/20] x86/alternative: Initialize temporary mm for patching Rick Edgecombe
2019-02-21 23:44 ` [PATCH v3 06/20] x86/alternative: Use temporary mm for text poking Rick Edgecombe
2019-02-21 23:44 ` [PATCH v3 07/20] x86/kgdb: Avoid redundant comparison of patched code Rick Edgecombe
2019-02-21 23:44 ` [PATCH v3 08/20] x86/ftrace: Set trampoline pages as executable Rick Edgecombe
2019-02-21 23:44 ` [PATCH v3 09/20] x86/kprobes: Set instruction page " Rick Edgecombe
2019-02-21 23:44 ` [PATCH v3 10/20] x86/module: Avoid breaking W^X while loading modules Rick Edgecombe
2019-02-21 23:44 ` [PATCH v3 11/20] x86/jump-label: Remove support for custom poker Rick Edgecombe
2019-02-21 23:44 ` [PATCH v3 12/20] x86/alternative: Remove the return value of text_poke_*() Rick Edgecombe
2019-02-21 23:44 ` [PATCH v3 13/20] x86/mm/cpa: Add set_direct_map_ functions Rick Edgecombe
2019-02-21 23:44 ` [PATCH v3 14/20] mm: Make hibernate handle unmapped pages Rick Edgecombe
2019-02-21 23:44 ` [PATCH v3 15/20] vmalloc: Add flag for free of special permsissions Rick Edgecombe
2019-02-21 23:44 ` [PATCH v3 16/20] modules: Use vmalloc special flag Rick Edgecombe
2019-02-21 23:44 ` [PATCH v3 17/20] bpf: " Rick Edgecombe
2019-02-21 23:44 ` [PATCH v3 18/20] x86/ftrace: " Rick Edgecombe
2019-02-22 0:22 ` Steven Rostedt
2019-02-22 0:55 ` Edgecombe, Rick P
2019-02-21 23:44 ` [PATCH v3 19/20] x86/kprobes: " Rick Edgecombe
2019-02-21 23:44 ` [PATCH v3 20/20] x86/alternative: Comment about module removal races Rick Edgecombe
2019-02-22 16:14 ` [PATCH v3 00/20] Merge text_poke fixes and executable lockdowns Borislav Petkov
2019-02-22 18:32 ` Edgecombe, Rick P
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