Stable Archive on lore.kernel.org
 help / color / Atom feed
From: Suzuki K Poulose <suzuki.poulose@arm.com>
To: stable@vger.kernel.org
Cc: suzuki.poulose@arm.com, linux-arm-kernel@lists.infradead.org,
	will@kernel.org, mark.rutland@arm.com, catalin.marinas@arm.com
Subject: [PATCH] arm64: cpufeature: Fix truncating a feature value
Date: Thu, 10 Oct 2019 12:08:56 +0100
Message-ID: <20191010110856.4376-1-suzuki.poulose@arm.com> (raw)

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)
-- 
2.21.0


             reply index

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-10-10 11:08 Suzuki K Poulose [this message]
2019-10-10 11:12 ` Suzuki K Poulose
2019-10-10 12:29   ` Greg KH
2019-10-10 12:46     ` Suzuki K Poulose
2019-10-10 13:16       ` Greg KH
2019-10-10 13:19     ` Suzuki K Poulose
2019-10-11  4:55       ` Greg KH
2019-10-11 10:31         ` Suzuki K Poulose
2019-10-11 12:13           ` Greg KH

Reply instructions:

You may reply publically to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20191010110856.4376-1-suzuki.poulose@arm.com \
    --to=suzuki.poulose@arm.com \
    --cc=catalin.marinas@arm.com \
    --cc=linux-arm-kernel@lists.infradead.org \
    --cc=mark.rutland@arm.com \
    --cc=stable@vger.kernel.org \
    --cc=will@kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

Stable Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/stable/0 stable/git/0.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 stable stable/ https://lore.kernel.org/stable \
		stable@vger.kernel.org
	public-inbox-index stable

Example config snippet for mirrors

Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.kernel.vger.stable


AGPL code for this site: git clone https://public-inbox.org/public-inbox.git