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| author | H. Peter Anvin <hpa@zytor.com> | 2009-04-01 22:35:00 +0400 |
|---|---|---|
| committer | H. Peter Anvin <hpa@zytor.com> | 2009-04-01 22:35:00 +0400 |
| commit | cd670599b7b00d9263f6f11a05c0edeb9cbedaf3 (patch) | |
| tree | e7aa26873f746baa1bd49cd92d3e7ab97c1716af | |
| parent | c549e71d073a6e9a4847497344db28a784061455 (diff) | |
| download | linux-cd670599b7b00d9263f6f11a05c0edeb9cbedaf3.tar.xz | |
x86, setup: guard against pre-ACPI 3 e820 code not updating %ecx
Impact: BIOS bug safety
For pre-ACPI 3 BIOSes, pre-initialize the end of the e820 buffer just
in case the BIOS returns an unchanged %ecx but without actually
touching the ACPI 3 extended flags field.
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
| -rw-r--r-- | arch/x86/boot/memory.c | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/arch/x86/boot/memory.c b/arch/x86/boot/memory.c index d5d2360763dc..5054c2ddd1a0 100644 --- a/arch/x86/boot/memory.c +++ b/arch/x86/boot/memory.c @@ -31,6 +31,12 @@ static int detect_memory_e820(void) struct e820entry *desc = boot_params.e820_map; static struct e820_ext_entry buf; /* static so it is zeroed */ + /* + * Set this here so that if the BIOS doesn't change this field + * but still doesn't change %ecx, we're still okay... + */ + buf.ext_flags = 1; + do { size = sizeof buf; |