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From: Huang Ying <ying.huang@intel.com>
To: "Eric W. Biederman" <ebiederm@xmission.com>,
	Pavel Machek <pavel@ucw.cz>,
	nigel@nigel.suspend2.net, "Rafael J. Wysocki" <rjw@sisk.pl>,
	Andrew Morton <akpm@linux-foundation.org>,
	Vivek Goyal <vgoyal@redhat.com>,
	mingo@elte.hu, Linus Torvalds <torvalds@linux-foundation.org>
Cc: Kexec Mailing List <kexec@lists.infradead.org>,
	linux-kernel@vger.kernel.org
Subject: [PATCH -v2 3/8] kexec jump: check code size in control page
Date: Fri, 08 Aug 2008 14:52:36 +0800	[thread overview]
Message-ID: <1218178356.22039.76.camel@caritas-dev.intel.com> (raw)

Kexec/Kexec-jump require code size in control page is less than
PAGE_SIZE/2. This patch add link-time checking for this.

ASSERT() of ld link script is used as the link-time checking
mechanism.

Signed-off-by: Huang Ying <ying.huang@intel.com>

---
 arch/x86/kernel/machine_kexec_32.c     |    2 +-
 arch/x86/kernel/relocate_kernel_32.S   |   10 +++++++---
 arch/x86/kernel/vmlinux_32.lds.S       |    2 ++
 arch/x86/kernel/vmlinux_check_32.lds.S |    7 +++++++
 include/asm-x86/kexec.h                |    4 ++++
 5 files changed, 21 insertions(+), 4 deletions(-)

--- a/arch/x86/kernel/machine_kexec_32.c
+++ b/arch/x86/kernel/machine_kexec_32.c
@@ -138,7 +138,7 @@ void machine_kexec(struct kimage *image)
 	}
 
 	control_page = page_address(image->control_code_page);
-	memcpy(control_page, relocate_kernel, PAGE_SIZE/2);
+	memcpy(control_page, relocate_kernel, KEXEC_CONTROL_CODE_MAX_SIZE);
 
 	relocate_kernel_ptr = control_page;
 	page_list[PA_CONTROL_PAGE] = __pa(control_page);
--- a/arch/x86/kernel/relocate_kernel_32.S
+++ b/arch/x86/kernel/relocate_kernel_32.S
@@ -20,10 +20,11 @@
 #define PAGE_ATTR (_PAGE_PRESENT | _PAGE_RW | _PAGE_ACCESSED | _PAGE_DIRTY)
 #define PAE_PGD_ATTR (_PAGE_PRESENT)
 
-/* control_page + PAGE_SIZE/2 ~ control_page + PAGE_SIZE * 3/4 are
- * used to save some data for jumping back
+/* control_page + KEXEC_CONTROL_CODE_MAX_SIZE
+ * ~ control_page + PAGE_SIZE * 3/4 are used to save some data for
+ * jumping back
  */
-#define DATA(offset)		(PAGE_SIZE/2+(offset))
+#define DATA(offset)		(KEXEC_CONTROL_CODE_MAX_SIZE+(offset))
 
 /* Minimal CPU state */
 #define ESP			DATA(0x0)
@@ -376,3 +377,6 @@ swap_pages:
 	popl	%ebx
 	popl	%ebp
 	ret
+
+	.globl kexec_control_code_size
+.set kexec_control_code_size, . - relocate_kernel
--- a/include/asm-x86/kexec.h
+++ b/include/asm-x86/kexec.h
@@ -41,6 +41,10 @@
 # define PAGES_NR		17
 #endif
 
+#ifdef CONFIG_X86_32
+# define KEXEC_CONTROL_CODE_MAX_SIZE	2048
+#endif
+
 #ifndef __ASSEMBLY__
 
 #include <linux/string.h>
--- a/arch/x86/kernel/vmlinux_32.lds.S
+++ b/arch/x86/kernel/vmlinux_32.lds.S
@@ -209,3 +209,5 @@ SECTIONS
 
   DWARF_DEBUG
 }
+
+#include "vmlinux_check_32.lds.S"
--- /dev/null
+++ b/arch/x86/kernel/vmlinux_check_32.lds.S
@@ -0,0 +1,7 @@
+/*
+ * Link time checks
+ */
+
+#include <asm/kexec.h>
+
+ASSERT(kexec_control_code_size <= KEXEC_CONTROL_CODE_MAX_SIZE, "kexec control code size is too big")



_______________________________________________
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kexec@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/kexec

WARNING: multiple messages have this Message-ID (diff)
From: Huang Ying <ying.huang@intel.com>
To: "Eric W. Biederman" <ebiederm@xmission.com>,
	Pavel Machek <pavel@ucw.cz>,
	nigel@nigel.suspend2.net, "Rafael J. Wysocki" <rjw@sisk.pl>,
	Andrew Morton <akpm@linux-foundation.org>,
	Vivek Goyal <vgoyal@redhat.com>,
	mingo@elte.hu, Linus Torvalds <torvalds@linux-foundation.org>
Cc: linux-kernel@vger.kernel.org,
	Kexec Mailing List <kexec@lists.infradead.org>
Subject: [PATCH -v2 3/8] kexec jump: check code size in control page
Date: Fri, 08 Aug 2008 14:52:36 +0800	[thread overview]
Message-ID: <1218178356.22039.76.camel@caritas-dev.intel.com> (raw)

Kexec/Kexec-jump require code size in control page is less than
PAGE_SIZE/2. This patch add link-time checking for this.

ASSERT() of ld link script is used as the link-time checking
mechanism.

Signed-off-by: Huang Ying <ying.huang@intel.com>

---
 arch/x86/kernel/machine_kexec_32.c     |    2 +-
 arch/x86/kernel/relocate_kernel_32.S   |   10 +++++++---
 arch/x86/kernel/vmlinux_32.lds.S       |    2 ++
 arch/x86/kernel/vmlinux_check_32.lds.S |    7 +++++++
 include/asm-x86/kexec.h                |    4 ++++
 5 files changed, 21 insertions(+), 4 deletions(-)

--- a/arch/x86/kernel/machine_kexec_32.c
+++ b/arch/x86/kernel/machine_kexec_32.c
@@ -138,7 +138,7 @@ void machine_kexec(struct kimage *image)
 	}
 
 	control_page = page_address(image->control_code_page);
-	memcpy(control_page, relocate_kernel, PAGE_SIZE/2);
+	memcpy(control_page, relocate_kernel, KEXEC_CONTROL_CODE_MAX_SIZE);
 
 	relocate_kernel_ptr = control_page;
 	page_list[PA_CONTROL_PAGE] = __pa(control_page);
--- a/arch/x86/kernel/relocate_kernel_32.S
+++ b/arch/x86/kernel/relocate_kernel_32.S
@@ -20,10 +20,11 @@
 #define PAGE_ATTR (_PAGE_PRESENT | _PAGE_RW | _PAGE_ACCESSED | _PAGE_DIRTY)
 #define PAE_PGD_ATTR (_PAGE_PRESENT)
 
-/* control_page + PAGE_SIZE/2 ~ control_page + PAGE_SIZE * 3/4 are
- * used to save some data for jumping back
+/* control_page + KEXEC_CONTROL_CODE_MAX_SIZE
+ * ~ control_page + PAGE_SIZE * 3/4 are used to save some data for
+ * jumping back
  */
-#define DATA(offset)		(PAGE_SIZE/2+(offset))
+#define DATA(offset)		(KEXEC_CONTROL_CODE_MAX_SIZE+(offset))
 
 /* Minimal CPU state */
 #define ESP			DATA(0x0)
@@ -376,3 +377,6 @@ swap_pages:
 	popl	%ebx
 	popl	%ebp
 	ret
+
+	.globl kexec_control_code_size
+.set kexec_control_code_size, . - relocate_kernel
--- a/include/asm-x86/kexec.h
+++ b/include/asm-x86/kexec.h
@@ -41,6 +41,10 @@
 # define PAGES_NR		17
 #endif
 
+#ifdef CONFIG_X86_32
+# define KEXEC_CONTROL_CODE_MAX_SIZE	2048
+#endif
+
 #ifndef __ASSEMBLY__
 
 #include <linux/string.h>
--- a/arch/x86/kernel/vmlinux_32.lds.S
+++ b/arch/x86/kernel/vmlinux_32.lds.S
@@ -209,3 +209,5 @@ SECTIONS
 
   DWARF_DEBUG
 }
+
+#include "vmlinux_check_32.lds.S"
--- /dev/null
+++ b/arch/x86/kernel/vmlinux_check_32.lds.S
@@ -0,0 +1,7 @@
+/*
+ * Link time checks
+ */
+
+#include <asm/kexec.h>
+
+ASSERT(kexec_control_code_size <= KEXEC_CONTROL_CODE_MAX_SIZE, "kexec control code size is too big")



             reply	other threads:[~2008-08-08  6:52 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-08-08  6:52 Huang Ying [this message]
2008-08-08  6:52 ` [PATCH -v2 3/8] kexec jump: check code size in control page Huang Ying
2008-08-08 14:09 ` Vivek Goyal
2008-08-08 14:09   ` Vivek Goyal
2008-08-11  1:02   ` Huang Ying
2008-08-11  1:02     ` Huang Ying

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