All of lore.kernel.org
 help / color / mirror / Atom feed
From: David Engraf <david.engraf@sysgo.com>
To: suzuki.poulose@arm.com, catalin.marinas@arm.com, will@kernel.org,
	broonie@kernel.org, mark.rutland@arm.com, elver@google.com,
	ebiederm@xmission.com, seanjc@google.com
Cc: linux-arm-kernel@lists.infradead.org,
	linux-kernel@vger.kernel.org,
	David Engraf <david.engraf@sysgo.com>
Subject: [PATCH] arm64: signal: nofpsimd: Do not allocate fp/simd context when not available
Date: Fri, 25 Feb 2022 11:40:08 +0100	[thread overview]
Message-ID: <20220225104008.820289-1-david.engraf@sysgo.com> (raw)

Commit 6d502b6ba1b2 ("arm64: signal: nofpsimd: Handle fp/simd context for
signal frames") introduced saving the fp/simd context for signal handling
only when support is available. But setup_sigframe_layout() always
reserves memory for fp/simd context. The additional memory is not touched
because preserve_fpsimd_context() is not called and thus the magic is
invalid.

This may lead to an error when parse_user_sigframe() checks the fp/simd
area and does not find a valid magic number.

Signed-off-by: David Engraf <david.engraf@sysgo.com>
---
 arch/arm64/kernel/signal.c | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/arch/arm64/kernel/signal.c b/arch/arm64/kernel/signal.c
index d8aaf4b6f432..3d66fba69016 100644
--- a/arch/arm64/kernel/signal.c
+++ b/arch/arm64/kernel/signal.c
@@ -577,10 +577,12 @@ static int setup_sigframe_layout(struct rt_sigframe_user_layout *user,
 {
 	int err;
 
-	err = sigframe_alloc(user, &user->fpsimd_offset,
-			     sizeof(struct fpsimd_context));
-	if (err)
-		return err;
+	if (system_supports_fpsimd()) {
+		err = sigframe_alloc(user, &user->fpsimd_offset,
+				     sizeof(struct fpsimd_context));
+		if (err)
+			return err;
+	}
 
 	/* fault information, if valid */
 	if (add_all || current->thread.fault_code) {
-- 
2.25.1


WARNING: multiple messages have this Message-ID (diff)
From: David Engraf <david.engraf@sysgo.com>
To: suzuki.poulose@arm.com, catalin.marinas@arm.com, will@kernel.org,
	broonie@kernel.org, mark.rutland@arm.com, elver@google.com,
	ebiederm@xmission.com, seanjc@google.com
Cc: linux-arm-kernel@lists.infradead.org,
	linux-kernel@vger.kernel.org,
	David Engraf <david.engraf@sysgo.com>
Subject: [PATCH] arm64: signal: nofpsimd: Do not allocate fp/simd context when not available
Date: Fri, 25 Feb 2022 11:40:08 +0100	[thread overview]
Message-ID: <20220225104008.820289-1-david.engraf@sysgo.com> (raw)

Commit 6d502b6ba1b2 ("arm64: signal: nofpsimd: Handle fp/simd context for
signal frames") introduced saving the fp/simd context for signal handling
only when support is available. But setup_sigframe_layout() always
reserves memory for fp/simd context. The additional memory is not touched
because preserve_fpsimd_context() is not called and thus the magic is
invalid.

This may lead to an error when parse_user_sigframe() checks the fp/simd
area and does not find a valid magic number.

Signed-off-by: David Engraf <david.engraf@sysgo.com>
---
 arch/arm64/kernel/signal.c | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/arch/arm64/kernel/signal.c b/arch/arm64/kernel/signal.c
index d8aaf4b6f432..3d66fba69016 100644
--- a/arch/arm64/kernel/signal.c
+++ b/arch/arm64/kernel/signal.c
@@ -577,10 +577,12 @@ static int setup_sigframe_layout(struct rt_sigframe_user_layout *user,
 {
 	int err;
 
-	err = sigframe_alloc(user, &user->fpsimd_offset,
-			     sizeof(struct fpsimd_context));
-	if (err)
-		return err;
+	if (system_supports_fpsimd()) {
+		err = sigframe_alloc(user, &user->fpsimd_offset,
+				     sizeof(struct fpsimd_context));
+		if (err)
+			return err;
+	}
 
 	/* fault information, if valid */
 	if (add_all || current->thread.fault_code) {
-- 
2.25.1


_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

             reply	other threads:[~2022-02-25 10:49 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-02-25 10:40 David Engraf [this message]
2022-02-25 10:40 ` [PATCH] arm64: signal: nofpsimd: Do not allocate fp/simd context when not available David Engraf
2022-02-25 17:57 ` Mark Brown
2022-02-25 17:57   ` Mark Brown
2022-02-28  7:56   ` David Engraf
2022-02-28  7:56     ` David Engraf
2022-02-28 13:20 ` Mark Brown
2022-02-28 13:20   ` Mark Brown
2022-02-28 18:34 ` Catalin Marinas
2022-02-28 18:34   ` Catalin Marinas
2022-03-07 22:03 ` Will Deacon
2022-03-07 22:03   ` Will Deacon

Reply instructions:

You may reply publicly 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=20220225104008.820289-1-david.engraf@sysgo.com \
    --to=david.engraf@sysgo.com \
    --cc=broonie@kernel.org \
    --cc=catalin.marinas@arm.com \
    --cc=ebiederm@xmission.com \
    --cc=elver@google.com \
    --cc=linux-arm-kernel@lists.infradead.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mark.rutland@arm.com \
    --cc=seanjc@google.com \
    --cc=suzuki.poulose@arm.com \
    --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
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.