The patch titled
Subject: percpu: cast percpu pointer in PERCPU_PTR() via unsigned long
has been added to the -mm mm-nonmm-unstable branch. Its filename is
percpu-cast-percpu-pointer-in-percpu_ptr-via-unsigned-long.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/percpu-cast-percpu-pointer-in-percpu_ptr-via-unsigned-long.patch
This patch will later appear in the mm-nonmm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: Uros Bizjak <ubizjak@xxxxxxxxx>
Subject: percpu: cast percpu pointer in PERCPU_PTR() via unsigned long
Date: Mon, 21 Oct 2024 10:07:38 +0200
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
Link: https://lkml.kernel.org/r/20241021080856.48746-3-ubizjak@xxxxxxxxx
Signed-off-by: Uros Bizjak <ubizjak@xxxxxxxxx>
Acked-by: Christoph Lameter <cl@xxxxxxxxx>
Cc: Dennis Zhou <dennis@xxxxxxxxxx>
Cc: Tejun Heo <tj@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/linux/percpu-defs.h | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
--- a/include/linux/percpu-defs.h~percpu-cast-percpu-pointer-in-percpu_ptr-via-unsigned-long
+++ a/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
_
Patches currently in -mm which might be from ubizjak@xxxxxxxxx are
perf-hw_breakpoint-use-err_ptr_pcpu-is_err_pcpu-and-ptr_err_pcpu-macros.patch
percpu-merge-verify_percpu_ptr-into-its-only-user.patch
percpu-introduce-percpu_ptr-macro.patch
percpu-cast-percpu-pointer-in-percpu_ptr-via-unsigned-long.patch
