diff mbox series

[3/3] percpu: Cast percpu pointer in PERCPU_PTR() via unsigned long

Message ID 20241021080856.48746-3-ubizjak@gmail.com (mailing list archive)
State New
Headers show
Series [1/3] percpu: Merge VERIFY_PERCPU_PTR() into its only user | expand

Commit Message

Uros Bizjak Oct. 21, 2024, 8:07 a.m. UTC 
Cast pointer from percpu address space to generic (kernel) address
space in PERCPU_PTR() macro via unsigned long intermediate cast [1].
This intermediate cast is also required to avoid build failure
when GCC's strict named address space checks for x86 targets [2]
are enabled.

Found by GCC's named address space checks.

[1] https://sparse.docs.kernel.org/en/latest/annotations.html#address-space-name
[2] https://gcc.gnu.org/onlinedocs/gcc/Named-Address-Spaces.html#x86-Named-Address-Spaces

Signed-off-by: Uros Bizjak <ubizjak@gmail.com>
Cc: Dennis Zhou <dennis@kernel.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Christoph Lameter <cl@linux.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
---
 include/linux/percpu-defs.h | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/include/linux/percpu-defs.h b/include/linux/percpu-defs.h
index e1cf7982424f..35842d1e3879 100644
--- a/include/linux/percpu-defs.h
+++ b/include/linux/percpu-defs.h
@@ -221,7 +221,10 @@  do {									\
 } while (0)
 
 #define PERCPU_PTR(__p)							\
-	(typeof(*(__p)) __force __kernel *)(__p);
+({									\
+	unsigned long __pcpu_ptr = (__force unsigned long)(__p);	\
+	(typeof(*(__p)) __force __kernel *)(__pcpu_ptr);		\
+})
 
 #ifdef CONFIG_SMP