Messages in this thread Patch in this message | | | From | ville.syrjala@linux ... | Subject | [PATCH] x86/gpu: Fix sign extension issue in Intel graphics stolen memory quirks | Date | Sun, 13 Apr 2014 12:45:03 +0300 |
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From: Ville Syrjälä <ville.syrjala@linux.intel.com>
Have the KB(),MB(),GB() macros produce unsigned longs to avoid uninteded sign extension issues with the gen2 memory size detection.
What happens is first the uint8_t returned by read_pci_config_byte() gets promoted to an int which gets multiplied by another int from the MB() macro, and finally the result gets sign extended to size_t.
Although this shouldn't be a problem in practice as all affected gen2 platforms are 32bit AFAIK, so size_t will be 32 bits.
Cc: H. Peter Anvin <hpa@zytor.com> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com> --- arch/x86/kernel/early-quirks.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/x86/kernel/early-quirks.c b/arch/x86/kernel/early-quirks.c index b0cc380..6e2537c 100644 --- a/arch/x86/kernel/early-quirks.c +++ b/arch/x86/kernel/early-quirks.c @@ -240,7 +240,7 @@ static u32 __init intel_stolen_base(int num, int slot, int func, size_t stolen_s return base; } -#define KB(x) ((x) * 1024) +#define KB(x) ((x) * 1024UL) #define MB(x) (KB (KB (x))) #define GB(x) (MB (KB (x))) -- 1.8.3.2 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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