From: Borislav Petkov <bp@alien8.de>
To: "H. Peter Anvin" <hpa@zytor.com>
Cc: Andy Lutomirski <luto@amacapital.net>,
Brian Gerst <brgerst@gmail.com>, X86 ML <x86@kernel.org>,
LKML <linux-kernel@vger.kernel.org>
Subject: [PATCH 4/6] x86/alternatives: Add an auxilary section
Date: Sun, 24 Jan 2016 10:28:46 +0100 [thread overview]
Message-ID: <1453627728-27197-5-git-send-email-bp@alien8.de> (raw)
In-Reply-To: <1453627728-27197-1-git-send-email-bp@alien8.de>
From: Borislav Petkov <bp@suse.de>
Add .altinstr_aux for additional instructions which will be used before
and/or during patching. All stuff which needs more sophisticated
patching should go there. See next patch.
Signed-off-by: Borislav Petkov <bp@suse.de>
---
arch/x86/kernel/vmlinux.lds.S | 11 +++++++++++
1 file changed, 11 insertions(+)
diff --git a/arch/x86/kernel/vmlinux.lds.S b/arch/x86/kernel/vmlinux.lds.S
index 4f1994257a18..04afe9b7e52a 100644
--- a/arch/x86/kernel/vmlinux.lds.S
+++ b/arch/x86/kernel/vmlinux.lds.S
@@ -195,6 +195,17 @@ SECTIONS
:init
#endif
+ /*
+ * Section for code used exclusively before alternatives are run. All
+ * references to such code must be patched out by alternatives, normally
+ * by using X86_FEATURE_ALWAYS CPU feature bit.
+ *
+ * See static_cpu_has() for an example.
+ */
+ .altinstr_aux : AT(ADDR(.altinstr_aux) - LOAD_OFFSET) {
+ *(.altinstr_aux)
+ }
+
INIT_DATA_SECTION(16)
.x86_cpu_dev.init : AT(ADDR(.x86_cpu_dev.init) - LOAD_OFFSET) {
--
2.3.5
next prev parent reply other threads:[~2016-01-24 9:29 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-01-24 9:28 [PATCH 0/6] x86/cpufeature: Cleanups and improvements v1 Borislav Petkov
2016-01-24 9:28 ` [PATCH 1/6] x86/cpufeature: Carve out X86_FEATURE_* Borislav Petkov
2016-01-24 9:28 ` [PATCH 2/6] x86/cpufeature: Replace the old static_cpu_has() with safe variant Borislav Petkov
2016-01-24 9:28 ` [PATCH 3/6] x86/cpufeature: Get rid of the non-asm goto variant Borislav Petkov
2016-01-24 9:28 ` Borislav Petkov [this message]
2016-01-24 9:28 ` [PATCH 5/6] x86/alternatives: Discard dynamic check after init Borislav Petkov
2016-01-24 9:28 ` [PATCH 6/6] x86/vdso: Use static_cpu_has() Borislav Petkov
2016-01-25 18:45 ` Andy Lutomirski
2016-01-25 18:58 ` Borislav Petkov
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