A signed feature value is truncated to turn to an unsigned value causing bad state in the system wide infrastructure. This affects the discovery of FP/ASIMD support on arm64. Fix this by making sure we cast it properly.
Fixes: 4f0a606bce5ec ("arm64: cpufeature: Track unsigned fields") Cc: stable@vger.kernel.org # v4.4 Cc: Will Deacon will@kernel.org Cc: Mark Rutland mark.rutland@arm.com Cc: Catalin Marinas catalin.marinas@arm.com Signed-off-by: Suzuki K Poulose suzuki.poulose@arm.com --- arch/arm64/include/asm/cpufeature.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/arch/arm64/include/asm/cpufeature.h b/arch/arm64/include/asm/cpufeature.h index 0a66f8241f18..9eb0d8072dd9 100644 --- a/arch/arm64/include/asm/cpufeature.h +++ b/arch/arm64/include/asm/cpufeature.h @@ -151,8 +151,8 @@ static inline u64 arm64_ftr_mask(struct arm64_ftr_bits *ftrp) static inline s64 arm64_ftr_value(struct arm64_ftr_bits *ftrp, u64 val) { return ftrp->sign ? - cpuid_feature_extract_field_width(val, ftrp->shift, ftrp->width) : - cpuid_feature_extract_unsigned_field_width(val, ftrp->shift, ftrp->width); + (s64)cpuid_feature_extract_field_width(val, ftrp->shift, ftrp->width) : + (s64)cpuid_feature_extract_unsigned_field_width(val, ftrp->shift, ftrp->width); }
static inline bool id_aa64mmfr0_mixed_endian_el0(u64 mmfr0)
All,
On 10/10/2019 12:08, Suzuki K Poulose wrote:
A signed feature value is truncated to turn to an unsigned value causing bad state in the system wide infrastructure. This affects the discovery of FP/ASIMD support on arm64. Fix this by making sure we cast it properly.
Fixes: 4f0a606bce5ec ("arm64: cpufeature: Track unsigned fields") Cc: stable@vger.kernel.org # v4.4
Please note that this patch is only applicable for stable 4.4 tree. I should have removed the Fixes tag.
Cheers Suzuki
On Thu, Oct 10, 2019 at 12:12:01PM +0100, Suzuki K Poulose wrote:
All,
On 10/10/2019 12:08, Suzuki K Poulose wrote:
A signed feature value is truncated to turn to an unsigned value causing bad state in the system wide infrastructure. This affects the discovery of FP/ASIMD support on arm64. Fix this by making sure we cast it properly.
Fixes: 4f0a606bce5ec ("arm64: cpufeature: Track unsigned fields") Cc: stable@vger.kernel.org # v4.4
Please note that this patch is only applicable for stable 4.4 tree. I should have removed the Fixes tag.
Why is it only for 4.4? That needs to be documented really really really well in the changelog as to why this is a one-off patch, and why we can't just take the relevant patches that are in Linus's tree instead.
Please fix up and resend.
thanks,
greg k-h
On 10/10/2019 13:29, Greg KH wrote:
On Thu, Oct 10, 2019 at 12:12:01PM +0100, Suzuki K Poulose wrote:
All,
On 10/10/2019 12:08, Suzuki K Poulose wrote:
A signed feature value is truncated to turn to an unsigned value causing bad state in the system wide infrastructure. This affects the discovery of FP/ASIMD support on arm64. Fix this by making sure we cast it properly.
Fixes: 4f0a606bce5ec ("arm64: cpufeature: Track unsigned fields") Cc: stable@vger.kernel.org # v4.4
Please note that this patch is only applicable for stable 4.4 tree. I should have removed the Fixes tag.
Why is it only for 4.4? That needs to be documented really really
This was fixed later in v4.6 onwards with commit 28c5dcb22f90113dea ("arm64: Rename cpuid_feature field extract routines") rather inadvertently.
really well in the changelog as to why this is a one-off patch, and why we can't just take the relevant patches that are in Linus's tree instead.
Please fix up and resend.
I can resend the patch with the above information included if you like.
Cheers Suzuki
On Thu, Oct 10, 2019 at 01:46:21PM +0100, Suzuki K Poulose wrote:
On 10/10/2019 13:29, Greg KH wrote:
On Thu, Oct 10, 2019 at 12:12:01PM +0100, Suzuki K Poulose wrote:
All,
On 10/10/2019 12:08, Suzuki K Poulose wrote:
A signed feature value is truncated to turn to an unsigned value causing bad state in the system wide infrastructure. This affects the discovery of FP/ASIMD support on arm64. Fix this by making sure we cast it properly.
Fixes: 4f0a606bce5ec ("arm64: cpufeature: Track unsigned fields") Cc: stable@vger.kernel.org # v4.4
Please note that this patch is only applicable for stable 4.4 tree. I should have removed the Fixes tag.
Why is it only for 4.4? That needs to be documented really really
This was fixed later in v4.6 onwards with commit 28c5dcb22f90113dea ("arm64: Rename cpuid_feature field extract routines") rather inadvertently.
really well in the changelog as to why this is a one-off patch, and why we can't just take the relevant patches that are in Linus's tree instead.
Please fix up and resend.
I can resend the patch with the above information included if you like.
As I said, please do, I can not take it otherwise.
greg k-h
A signed feature value is truncated to turn to an unsigned value causing bad state in the system wide infrastructure. This affects the discovery of FP/ASIMD support on arm64. Fix this by making sure we cast it properly.
This was inadvertently fixed upstream in v4.6 onwards with the following : commit 28c5dcb22f90113dea ("arm64: Rename cpuid_feature field extract routines")
Cc: stable@vger.kernel.org # v4.4 Cc: Will Deacon will@kernel.org Cc: Mark Rutland mark.rutland@arm.com Cc: Catalin Marinas catalin.marinas@arm.com Signed-off-by: Suzuki K Poulose suzuki.poulose@arm.com --- arch/arm64/include/asm/cpufeature.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/arch/arm64/include/asm/cpufeature.h b/arch/arm64/include/asm/cpufeature.h index 0a66f8241f18..9eb0d8072dd9 100644 --- a/arch/arm64/include/asm/cpufeature.h +++ b/arch/arm64/include/asm/cpufeature.h @@ -151,8 +151,8 @@ static inline u64 arm64_ftr_mask(struct arm64_ftr_bits *ftrp) static inline s64 arm64_ftr_value(struct arm64_ftr_bits *ftrp, u64 val) { return ftrp->sign ? - cpuid_feature_extract_field_width(val, ftrp->shift, ftrp->width) : - cpuid_feature_extract_unsigned_field_width(val, ftrp->shift, ftrp->width); + (s64)cpuid_feature_extract_field_width(val, ftrp->shift, ftrp->width) : + (s64)cpuid_feature_extract_unsigned_field_width(val, ftrp->shift, ftrp->width); }
static inline bool id_aa64mmfr0_mixed_endian_el0(u64 mmfr0)
On Thu, Oct 10, 2019 at 02:19:43PM +0100, Suzuki K Poulose wrote:
A signed feature value is truncated to turn to an unsigned value causing bad state in the system wide infrastructure. This affects the discovery of FP/ASIMD support on arm64. Fix this by making sure we cast it properly.
This was inadvertently fixed upstream in v4.6 onwards with the following : commit 28c5dcb22f90113dea ("arm64: Rename cpuid_feature field extract routines")
What prevents us from just taking that commit instead? You did not document that here at all, which I thought I asked for.
Also, you only need 12 digits for a sha1, 28c5dcb22f90 ("arm64: Rename cpuid_feature field extract routines") would be just fine :)
thanks,
greg k-h
Hi Greg,
On 11/10/2019 05:55, Greg KH wrote:
On Thu, Oct 10, 2019 at 02:19:43PM +0100, Suzuki K Poulose wrote:
A signed feature value is truncated to turn to an unsigned value causing bad state in the system wide infrastructure. This affects the discovery of FP/ASIMD support on arm64. Fix this by making sure we cast it properly.
This was inadvertently fixed upstream in v4.6 onwards with the following : commit 28c5dcb22f90113dea ("arm64: Rename cpuid_feature field extract routines")
What prevents us from just taking that commit instead? You did not document that here at all, which I thought I asked for.
Sorry, I missed that part. So, that change introduces helpers to extract feature fields based on the sign. And it also depends on
commit ff96f7bc7bf6 ("arm64: capabilities: Handle sign of the feature bit")
which introduces "sign" bit for the "capability" list and modifies the generic capability->matches() helpers to use the hint to switch to the appropriate helpers.
I could backport parts of the commit 28c5dcb22f90 dropping the bits that affect the changes mentioned above.
Also, you only need 12 digits for a sha1, 28c5dcb22f90 ("arm64: Rename cpuid_feature field extract routines") would be just fine :)
Yea, I understand. Its simply a pain to count the numbers, so I make sure to pickup something that looks larger than the 12 ;-). I will try to stick to that :-)
Cheers Suzuki
On Fri, Oct 11, 2019 at 11:31:30AM +0100, Suzuki K Poulose wrote:
Hi Greg,
On 11/10/2019 05:55, Greg KH wrote:
On Thu, Oct 10, 2019 at 02:19:43PM +0100, Suzuki K Poulose wrote:
A signed feature value is truncated to turn to an unsigned value causing bad state in the system wide infrastructure. This affects the discovery of FP/ASIMD support on arm64. Fix this by making sure we cast it properly.
This was inadvertently fixed upstream in v4.6 onwards with the following : commit 28c5dcb22f90113dea ("arm64: Rename cpuid_feature field extract routines")
What prevents us from just taking that commit instead? You did not document that here at all, which I thought I asked for.
Sorry, I missed that part. So, that change introduces helpers to extract feature fields based on the sign. And it also depends on
commit ff96f7bc7bf6 ("arm64: capabilities: Handle sign of the feature bit")
which introduces "sign" bit for the "capability" list and modifies the generic capability->matches() helpers to use the hint to switch to the appropriate helpers.
That's ok, does that cause any problems? We always want the original patch instead of a one-off patch as that way we do not diverge.
I could backport parts of the commit 28c5dcb22f90 dropping the bits that affect the changes mentioned above.
Please do, that is always prefered as well, but do the first thing above if at all possible.
Also, you only need 12 digits for a sha1, 28c5dcb22f90 ("arm64: Rename cpuid_feature field extract routines") would be just fine :)
Yea, I understand. Its simply a pain to count the numbers, so I make sure to pickup something that looks larger than the 12 ;-). I will try to stick to that :-)
git show -s --abbrev-commit --abbrev=12 --pretty=format:"%h ("%s")%n" will give you the correct format. I suggest making it a git alias :)
Or, use: [core] abbrev = 12 in your .gitconfig file.
thanks,
greg k-h
linux-stable-mirror@lists.linaro.org
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Greg KH -
Suzuki K Poulose