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* [PATCH] x86, efi: initial the local variable of DataSize to zero
@ 2013-04-26 17:19 ` Lee, Chun-Yi
  0 siblings, 0 replies; 12+ messages in thread
From: Lee, Chun-Yi @ 2013-04-26 17:19 UTC (permalink / raw)
  To: matt.fleming-ral2JQCrhuEAvxtiuMwx3w, mjg59-1xO5oi07KQx4cg9Nei1l7Q
  Cc: linux-efi-u79uwXL29TY76Z2rM5mHXA,
	linux-kernel-u79uwXL29TY76Z2rM5mHXA, Lee, Chun-Yi,
	Matthew Garrett, H. Peter Anvin

That will be better initial the value of DataSize to zero for the input of
GetVariable(), otherwise we will feed a random value. The debug log of input
DataSize like this:

...
[  195.915612] EFI Variables Facility v0.08 2004-May-17
[  195.915819] efi: size: 18446744071581821342
[  195.915969] efi:  size': 18446744071581821342
[  195.916324] efi: size: 18446612150714306560
[  195.916632] efi:  size': 18446612150714306560
[  195.917159] efi: size: 18446612150714306560
[  195.917453] efi:  size': 18446612150714306560
...

Found on Acer Aspire V3 BIOS, it will not return the size of data if we input a
non-zero DataSize.

Cc: Matthew Garrett <mjg-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
Cc: Matt Fleming <matt.fleming-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
Cc: H. Peter Anvin <hpa-YMNOUZJC4hwAvxtiuMwx3w@public.gmane.org>
Signed-off-by: Lee, Chun-Yi <jlee-IBi9RG/b67k@public.gmane.org>
---
 arch/x86/platform/efi/efi.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/arch/x86/platform/efi/efi.c b/arch/x86/platform/efi/efi.c
index e4a86a6..cb59732 100644
--- a/arch/x86/platform/efi/efi.c
+++ b/arch/x86/platform/efi/efi.c
@@ -204,7 +204,7 @@ static efi_status_t virt_efi_get_next_variable(unsigned long *name_size,
 	}
 
 	if (boot_used_size && !finished) {
-		unsigned long size;
+		unsigned long size = 0;
 		u32 attr;
 		efi_status_t s;
 		void *tmp;
-- 
1.6.0.2

^ permalink raw reply related	[flat|nested] 12+ messages in thread
* [PATCH] x86, efi: initial the local variable of DataSize to zero
@ 2013-05-02 14:07 ` Lee, Chun-Yi
  0 siblings, 0 replies; 12+ messages in thread
From: Lee, Chun-Yi @ 2013-05-02 14:07 UTC (permalink / raw)
  To: matt.fleming-ral2JQCrhuEAvxtiuMwx3w, mjg59-1xO5oi07KQx4cg9Nei1l7Q
  Cc: linux-efi-u79uwXL29TY76Z2rM5mHXA,
	linux-kernel-u79uwXL29TY76Z2rM5mHXA, Lee, Chun-Yi,
	Matthew Garrett, H. Peter Anvin

That will be better initial the value of DataSize to zero for the input of
GetVariable(), otherwise we will feed a random value. The debug log of input
DataSize like this:

...
[  195.915612] EFI Variables Facility v0.08 2004-May-17
[  195.915819] efi: size: 18446744071581821342
[  195.915969] efi:  size': 18446744071581821342
[  195.916324] efi: size: 18446612150714306560
[  195.916632] efi:  size': 18446612150714306560
[  195.917159] efi: size: 18446612150714306560
[  195.917453] efi:  size': 18446612150714306560
...

The size' is value that was returned by BIOS.

After applied this patch:
[   82.442042] EFI Variables Facility v0.08 2004-May-17
[   82.442202] efi: size: 0
[   82.442360] efi:  size': 1039
[   82.443828] efi: size: 0
[   82.444127] efi:  size': 2616
[   82.447057] efi: size: 0
[   82.447356] efi:  size': 5832
...

Found on Acer Aspire V3 BIOS, it will not return the size of data if we input a
non-zero DataSize.

Cc: Matthew Garrett <mjg-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
Cc: Matt Fleming <matt.fleming-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
Cc: H. Peter Anvin <hpa-YMNOUZJC4hwAvxtiuMwx3w@public.gmane.org>
Signed-off-by: Lee, Chun-Yi <jlee-IBi9RG/b67k@public.gmane.org>
---
 arch/x86/platform/efi/efi.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/arch/x86/platform/efi/efi.c b/arch/x86/platform/efi/efi.c
index e4a86a6..cb59732 100644
--- a/arch/x86/platform/efi/efi.c
+++ b/arch/x86/platform/efi/efi.c
@@ -204,7 +204,7 @@ static efi_status_t virt_efi_get_next_variable(unsigned long *name_size,
 	}
 
 	if (boot_used_size && !finished) {
-		unsigned long size;
+		unsigned long size = 0;
 		u32 attr;
 		efi_status_t s;
 		void *tmp;
-- 
1.6.0.2

^ permalink raw reply related	[flat|nested] 12+ messages in thread

end of thread, other threads:[~2013-05-03  8:50 UTC | newest]

Thread overview: 12+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2013-04-26 17:19 [PATCH] x86, efi: initial the local variable of DataSize to zero Lee, Chun-Yi
2013-04-26 17:19 ` Lee, Chun-Yi
     [not found] ` <1366996767-8234-1-git-send-email-jlee-IBi9RG/b67k@public.gmane.org>
2013-04-29  9:55   ` Matt Fleming
2013-04-29  9:55     ` Matt Fleming
2013-04-29 10:25   ` joeyli
2013-04-29 10:25     ` joeyli
     [not found]     ` <1367231111.22858.55.camel-ONCj+Eqt86TasUa73XJKwA@public.gmane.org>
2013-04-29 10:34       ` joeyli
2013-04-29 10:34         ` joeyli
  -- strict thread matches above, loose matches on Subject: below --
2013-05-02 14:07 Lee, Chun-Yi
2013-05-02 14:07 ` Lee, Chun-Yi
     [not found] ` <1367503621-13004-1-git-send-email-jlee-IBi9RG/b67k@public.gmane.org>
2013-05-03  8:50   ` Matt Fleming
2013-05-03  8:50     ` Matt Fleming

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