From: "H. Peter Anvin" <hpa@linux.intel.com> To: linux-kernel@vger.kernel.org Cc: vgoyal@redhat.com, hbabu@us.ibm.com, kexec@lists.infradead.org, ying.huang@intel.com, mingo@elte.hu, tglx@linutronix.de, ebiederm@xmission.com, sam@ravnborg.org, "H. Peter Anvin" <hpa@zytor.com> Subject: [PATCH 12/14] x86, boot: zero EFLAGS on 32 bits Date: Thu, 7 May 2009 15:27:00 -0700 [thread overview] Message-ID: <1241735222-6640-13-git-send-email-hpa@linux.intel.com> (raw) In-Reply-To: <1241735222-6640-1-git-send-email-hpa@linux.intel.com> From: H. Peter Anvin <hpa@zytor.com> The 64-bit code already clears EFLAGS as soon as it has a stack. This seems like a reasonable precaution, so do it on 32 bits as well. [ Impact: extra paranoia ] Signed-off-by: H. Peter Anvin <hpa@zytor.com> --- arch/x86/boot/compressed/head_32.S | 10 ++++++++-- 1 files changed, 8 insertions(+), 2 deletions(-) diff --git a/arch/x86/boot/compressed/head_32.S b/arch/x86/boot/compressed/head_32.S index 47636b3..48c2047 100644 --- a/arch/x86/boot/compressed/head_32.S +++ b/arch/x86/boot/compressed/head_32.S @@ -12,9 +12,9 @@ * the page directory. [According to comments etc elsewhere on a compressed * kernel it will end up at 0x1000 + 1Mb I hope so as I assume this. - AC] * - * Page 0 is deliberately kept safe, since System Management Mode code in + * Page 0 is deliberately kept safe, since System Management Mode code in * laptops may need to access the BIOS data stored there. This is also - * useful for future device drivers that either access the BIOS via VM86 + * useful for future device drivers that either access the BIOS via VM86 * mode. */ @@ -84,6 +84,12 @@ ENTRY(startup_32) leal boot_stack_end(%ebx), %esp /* + * Zero EFLAGS + */ + pushl $0 + popfl + +/* * Copy the compressed kernel to the end of our buffer * where decompression in place becomes safe. */ -- 1.6.0.6
WARNING: multiple messages have this Message-ID (diff)
From: "H. Peter Anvin" <hpa@linux.intel.com> To: linux-kernel@vger.kernel.org Cc: "H. Peter Anvin" <hpa@zytor.com>, kexec@lists.infradead.org, hbabu@us.ibm.com, ebiederm@xmission.com, ying.huang@intel.com, mingo@elte.hu, sam@ravnborg.org, tglx@linutronix.de, vgoyal@redhat.com Subject: [PATCH 12/14] x86, boot: zero EFLAGS on 32 bits Date: Thu, 7 May 2009 15:27:00 -0700 [thread overview] Message-ID: <1241735222-6640-13-git-send-email-hpa@linux.intel.com> (raw) In-Reply-To: <1241735222-6640-1-git-send-email-hpa@linux.intel.com> From: H. Peter Anvin <hpa@zytor.com> The 64-bit code already clears EFLAGS as soon as it has a stack. This seems like a reasonable precaution, so do it on 32 bits as well. [ Impact: extra paranoia ] Signed-off-by: H. Peter Anvin <hpa@zytor.com> --- arch/x86/boot/compressed/head_32.S | 10 ++++++++-- 1 files changed, 8 insertions(+), 2 deletions(-) diff --git a/arch/x86/boot/compressed/head_32.S b/arch/x86/boot/compressed/head_32.S index 47636b3..48c2047 100644 --- a/arch/x86/boot/compressed/head_32.S +++ b/arch/x86/boot/compressed/head_32.S @@ -12,9 +12,9 @@ * the page directory. [According to comments etc elsewhere on a compressed * kernel it will end up at 0x1000 + 1Mb I hope so as I assume this. - AC] * - * Page 0 is deliberately kept safe, since System Management Mode code in + * Page 0 is deliberately kept safe, since System Management Mode code in * laptops may need to access the BIOS data stored there. This is also - * useful for future device drivers that either access the BIOS via VM86 + * useful for future device drivers that either access the BIOS via VM86 * mode. */ @@ -84,6 +84,12 @@ ENTRY(startup_32) leal boot_stack_end(%ebx), %esp /* + * Zero EFLAGS + */ + pushl $0 + popfl + +/* * Copy the compressed kernel to the end of our buffer * where decompression in place becomes safe. */ -- 1.6.0.6 _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec
next prev parent reply other threads:[~2009-05-07 22:32 UTC|newest] Thread overview: 90+ messages / expand[flat|nested] mbox.gz Atom feed top 2009-05-07 22:26 [PATCH 00/14] RFC: x86: relocatable kernel changes H. Peter Anvin 2009-05-07 22:26 ` H. Peter Anvin 2009-05-07 22:26 ` [PATCH 01/14] x86, boot: align the .bss section in the decompressor H. Peter Anvin 2009-05-07 22:26 ` H. Peter Anvin 2009-05-08 7:17 ` Sam Ravnborg 2009-05-08 7:17 ` Sam Ravnborg 2009-05-08 8:18 ` Eric Dumazet 2009-05-08 8:18 ` Eric Dumazet 2009-05-08 16:54 ` H. Peter Anvin 2009-05-08 16:54 ` H. Peter Anvin 2009-05-08 7:53 ` Cyrill Gorcunov 2009-05-08 7:53 ` Cyrill Gorcunov 2009-05-08 17:03 ` H. Peter Anvin 2009-05-08 17:03 ` H. Peter Anvin 2009-05-08 17:15 ` Cyrill Gorcunov 2009-05-08 17:15 ` Cyrill Gorcunov 2009-05-08 17:21 ` H. Peter Anvin 2009-05-08 17:21 ` H. Peter Anvin 2009-05-07 22:26 ` [PATCH 02/14] x86, boot: honor CONFIG_PHYSICAL_START when relocatable H. Peter Anvin 2009-05-07 22:26 ` H. Peter Anvin 2009-05-08 7:34 ` Sam Ravnborg 2009-05-08 7:34 ` Sam Ravnborg 2009-05-08 16:58 ` H. Peter Anvin 2009-05-08 16:58 ` H. Peter Anvin 2009-05-07 22:26 ` [PATCH 03/14] x86, config: change defaults PHYSICAL_START and PHYSICAL_ALIGN H. Peter Anvin 2009-05-07 22:26 ` H. Peter Anvin 2009-05-08 7:36 ` Sam Ravnborg 2009-05-08 7:36 ` Sam Ravnborg 2009-05-08 9:47 ` Ingo Molnar 2009-05-08 9:47 ` Ingo Molnar 2009-05-08 17:01 ` H. Peter Anvin 2009-05-08 17:01 ` H. Peter Anvin 2009-05-07 22:26 ` [PATCH 04/14] x86, boot: unify use LOAD_PHYSICAL_ADDR and LOAD_PHYSICAL_ALIGN H. Peter Anvin 2009-05-07 22:26 ` H. Peter Anvin 2009-05-07 22:26 ` [PATCH 05/14] kbuild: allow compressors (gzip, bzip2, lzma) to take multiple inputs H. Peter Anvin 2009-05-07 22:26 ` H. Peter Anvin 2009-05-08 7:42 ` Sam Ravnborg 2009-05-08 7:42 ` Sam Ravnborg 2009-05-08 20:18 ` H. Peter Anvin 2009-05-08 20:18 ` H. Peter Anvin 2009-05-08 20:47 ` Sam Ravnborg 2009-05-08 20:47 ` Sam Ravnborg 2009-05-08 20:49 ` H. Peter Anvin 2009-05-08 20:49 ` H. Peter Anvin 2009-05-08 21:33 ` Sam Ravnborg 2009-05-08 21:33 ` Sam Ravnborg 2009-05-07 22:26 ` [PATCH 06/14] x86: add a Kconfig symbol for when relocations are needed H. Peter Anvin 2009-05-07 22:26 ` H. Peter Anvin 2009-05-07 22:26 ` [PATCH 07/14] x86, boot: simplify arch/x86/boot/compressed/Makefile H. Peter Anvin 2009-05-07 22:26 ` H. Peter Anvin 2009-05-08 7:45 ` Sam Ravnborg 2009-05-08 7:45 ` Sam Ravnborg 2009-05-07 22:26 ` [PATCH 08/14] x86, boot: use BP_scratch in arch/x86/boot/compressed/head_*.S H. Peter Anvin 2009-05-07 22:26 ` H. Peter Anvin 2009-05-07 22:26 ` [PATCH 09/14] x86, boot: add new runtime_address and runtime_size bzImage fields H. Peter Anvin 2009-05-07 22:26 ` H. Peter Anvin 2009-05-08 7:55 ` Sam Ravnborg 2009-05-08 7:55 ` Sam Ravnborg 2009-05-08 21:09 ` H. Peter Anvin 2009-05-08 21:09 ` H. Peter Anvin 2009-05-08 21:35 ` Sam Ravnborg 2009-05-08 21:35 ` Sam Ravnborg 2009-05-07 22:26 ` [PATCH 10/14] x86, doc: document the runtime_start " H. Peter Anvin 2009-05-07 22:26 ` H. Peter Anvin 2009-05-07 22:26 ` [PATCH 11/14] x86, boot: use rep movsq to move kernel on 64 bits H. Peter Anvin 2009-05-07 22:26 ` H. Peter Anvin 2009-05-07 22:27 ` H. Peter Anvin [this message] 2009-05-07 22:27 ` [PATCH 12/14] x86, boot: zero EFLAGS on 32 bits H. Peter Anvin 2009-05-07 22:27 ` [PATCH 13/14] x86: make CONFIG_RELOCATABLE the default H. Peter Anvin 2009-05-07 22:27 ` H. Peter Anvin 2009-05-07 22:27 ` [PATCH 14/14] x86, defconfig: update defconfigs to relocatable H. Peter Anvin 2009-05-07 22:27 ` H. Peter Anvin 2009-05-08 1:23 ` [PATCH 00/14] RFC: x86: relocatable kernel changes Eric W. Biederman 2009-05-08 1:23 ` Eric W. Biederman 2009-05-08 5:31 ` H. Peter Anvin 2009-05-08 5:31 ` H. Peter Anvin 2009-05-08 6:54 ` Eric W. Biederman 2009-05-08 6:54 ` Eric W. Biederman 2009-05-08 18:04 ` H. Peter Anvin 2009-05-08 18:04 ` H. Peter Anvin 2009-05-08 18:47 ` H. Peter Anvin 2009-05-08 18:47 ` H. Peter Anvin 2009-05-11 5:18 ` RFC: x86: relocatable kernel changes (revised spec) H. Peter Anvin 2009-05-11 5:18 ` H. Peter Anvin 2009-05-11 11:54 ` Eric W. Biederman 2009-05-11 11:54 ` Eric W. Biederman 2009-05-11 16:03 ` H. Peter Anvin 2009-05-11 16:03 ` H. Peter Anvin 2009-05-11 17:56 ` RFC: x86: relocatable kernel changes (revised spec v2) H. Peter Anvin 2009-05-11 17:56 ` H. Peter Anvin
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