[PATCH v3 4/6] percpu: Use TYPEOF_UNQUAL() in *_cpu_ptr() accessors

Uros Bizjak
2024-12-08T20:47:30Z

Use TYPEOF_UNQUAL() macro to declare the return type of *_cpu_ptr()
accessors in the generic named address space to avoid access to
data from pointer to non-enclosed address space type of errors.

Signed-off-by: Uros Bizjak <ubizjak@gmail.com>
Acked-by: Nadav Amit <nadav.amit@gmail.com>
Acked-by: Christoph Lameter <cl@linux.com>
Cc: Dennis Zhou <dennis@kernel.org>
Cc: Tejun Heo <tj@kernel.org>
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>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
---
arch/x86/include/asm/percpu.h | 8 ++++++--
include/linux/percpu-defs.h | 2 +-
2 files changed, 7 insertions(+), 3 deletions(-)

diff --git a/arch/x86/include/asm/percpu.h b/arch/x86/include/asm/percpu.h
index 666e4137b09f..27f668660abe 100644
--- a/arch/x86/include/asm/percpu.h
+++ b/arch/x86/include/asm/percpu.h
@@ -73,10 +73,14 @@
unsigned long tcp_ptr__ = raw_cpu_read_long(this_cpu_off); \
\
tcp_ptr__ += (__force unsigned long)(_ptr); \
- (typeof(*(_ptr)) __kernel __force *)tcp_ptr__; \
+ (TYPEOF_UNQUAL(*(_ptr)) __force __kernel *)tcp_ptr__; \
})
#else
-#define arch_raw_cpu_ptr(_ptr) ({ BUILD_BUG(); (typeof(_ptr))0; })
+#define arch_raw_cpu_ptr(_ptr) \
+({ \
+ BUILD_BUG(); \
+ (TYPEOF_UNQUAL(*(_ptr)) __force __kernel *)0; \
+})
#endif

#define PER_CPU_VAR(var) %__percpu_seg:(var)__percpu_rel
diff --git a/include/linux/percpu-defs.h b/include/linux/percpu-defs.h
index 266297b21a5d..2921ea97d242 100644
--- a/include/linux/percpu-defs.h
+++ b/include/linux/percpu-defs.h
@@ -223,7 +223,7 @@ do { \
#define PERCPU_PTR(__p) \
({ \
unsigned long __pcpu_ptr = (__force unsigned long)(__p); \
- (typeof(*(__p)) __force __kernel *)(__pcpu_ptr); \
+ (TYPEOF_UNQUAL(*(__p)) __force __kernel *)(__pcpu_ptr); \
})

#ifdef CONFIG_SMP
--
2.42.0