[PATCH 3/3] percpu: Cast percpu pointer in PERCPU_PTR() via unsigned long
From: Uros Bizjak
Date: Mon Oct 21 2024 - 04:09:36 EST
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@xxxxxxxxx>
Cc: Dennis Zhou <dennis@xxxxxxxxxx>
Cc: Tejun Heo <tj@xxxxxxxxxx>
Cc: Christoph Lameter <cl@xxxxxxxxx>
Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/linux/percpu-defs.h | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
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
--
2.47.0