[PATCH] x86/percpu: Disable named address spaces for UBSAN_BOOL with KASAN for GCC < 14.2

[PATCH] x86/percpu: Disable named address spaces for UBSAN_BOOL with KASAN for GCC < 14.2

[Uros Bizjak]

GCC < 14.2 does not correctly propagate address space qualifiers
with -fsanitize=bool,enum. Together with address sanitizer then
causes that load to be sanitized.

Disable named address spaces for GCC < 14.2 when both, UBSAN_BOOL
and KASAN are enabled.

Reported-by: Matt Fleming <matt@readmodwrite.com>
Closes: https://lore.kernel.org/lkml/20241213190119.3449103-1-matt@readmodwrite.com/
Signed-off-by: Uros Bizjak <ubizjak@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
---
 arch/x86/Kconfig | 20 +++++++++++---------
 1 file changed, 11 insertions(+), 9 deletions(-)

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 95ea2b4b95db..60c2a16c7801 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -2369,18 +2369,20 @@ config CC_HAS_NAMED_AS
 	def_bool $(success,echo 'int __seg_fs fs; int __seg_gs gs;' | $(CC) -x c - -S -o /dev/null)
 	depends on CC_IS_GCC
 
+#
+# -fsanitize=kernel-address (KASAN) and -fsanitize=thread (KCSAN)
+# are incompatible with named address spaces with GCC < 13.3
+# (see GCC PR sanitizer/111736 and also PR sanitizer/115172).
+#
+
 config CC_HAS_NAMED_AS_FIXED_SANITIZERS
-	def_bool CC_IS_GCC && GCC_VERSION >= 130300
+	def_bool y
+	depends on !(KASAN || KCSAN) || GCC_VERSION >= 130300
+	depends on !(UBSAN_BOOL && KASAN) || GCC_VERSION >= 140200
 
 config USE_X86_SEG_SUPPORT
-	def_bool y
-	depends on CC_HAS_NAMED_AS
-	#
-	# -fsanitize=kernel-address (KASAN) and -fsanitize=thread
-	# (KCSAN) are incompatible with named address spaces with
-	# GCC < 13.3 - see GCC PR sanitizer/111736.
-	#
-	depends on !(KASAN || KCSAN) || CC_HAS_NAMED_AS_FIXED_SANITIZERS
+	def_bool CC_HAS_NAMED_AS
+	depends on CC_HAS_NAMED_AS_FIXED_SANITIZERS
 
 config CC_HAS_SLS
 	def_bool $(cc-option,-mharden-sls=all)
-- 
2.48.1

[tip: x86/asm] x86/percpu: Disable named address spaces for UBSAN_BOOL with KASAN for GCC < 14.2

[tip-bot2 for Uros Bizjak]

The following commit has been merged into the x86/asm branch of tip:

Commit-ID:     b6762467a09ba8838c499e4f36561e82fc608ed1
Gitweb:        https://git.kernel.org/tip/b6762467a09ba8838c499e4f36561e82fc608ed1
Author:        Uros Bizjak <ubizjak@gmail.com>
AuthorDate:    Thu, 27 Feb 2025 15:06:58 +01:00
Committer:     Ingo Molnar <mingo@kernel.org>
CommitterDate: Thu, 27 Feb 2025 19:24:48 +01:00

x86/percpu: Disable named address spaces for UBSAN_BOOL with KASAN for GCC < 14.2

GCC < 14.2 does not correctly propagate address space qualifiers
with -fsanitize=bool,enum. Together with address sanitizer then
causes that load to be sanitized.

Disable named address spaces for GCC < 14.2 when both, UBSAN_BOOL
and KASAN are enabled.

Reported-by: Matt Fleming <matt@readmodwrite.com>
Signed-off-by: Uros Bizjak <ubizjak@gmail.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20250227140715.2276353-1-ubizjak@gmail.com
Closes: https://lore.kernel.org/lkml/20241213190119.3449103-1-matt@readmodwrite.com/
---
 arch/x86/Kconfig | 20 +++++++++++---------
 1 file changed, 11 insertions(+), 9 deletions(-)

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 6595b35..867ec8a 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -2441,18 +2441,20 @@ config CC_HAS_NAMED_AS
 	def_bool $(success,echo 'int __seg_fs fs; int __seg_gs gs;' | $(CC) -x c - -S -o /dev/null)
 	depends on CC_IS_GCC
 
+#
+# -fsanitize=kernel-address (KASAN) and -fsanitize=thread (KCSAN)
+# are incompatible with named address spaces with GCC < 13.3
+# (see GCC PR sanitizer/111736 and also PR sanitizer/115172).
+#
+
 config CC_HAS_NAMED_AS_FIXED_SANITIZERS
-	def_bool CC_IS_GCC && GCC_VERSION >= 130300
+	def_bool y
+	depends on !(KASAN || KCSAN) || GCC_VERSION >= 130300
+	depends on !(UBSAN_BOOL && KASAN) || GCC_VERSION >= 140200
 
 config USE_X86_SEG_SUPPORT
-	def_bool y
-	depends on CC_HAS_NAMED_AS
-	#
-	# -fsanitize=kernel-address (KASAN) and -fsanitize=thread
-	# (KCSAN) are incompatible with named address spaces with
-	# GCC < 13.3 - see GCC PR sanitizer/111736.
-	#
-	depends on !(KASAN || KCSAN) || CC_HAS_NAMED_AS_FIXED_SANITIZERS
+	def_bool CC_HAS_NAMED_AS
+	depends on CC_HAS_NAMED_AS_FIXED_SANITIZERS
 
 config CC_HAS_SLS
 	def_bool $(cc-option,-mharden-sls=all)