The patch titled
Subject: err.h: add ERR_PTR_PCPU(), PTR_ERR_PCPU() and IS_ERR_PCPU() functions
has been added to the -mm mm-unstable branch. Its filename is
errh-add-err_ptr_pcpu-ptr_err_pcpu-and-is_err_pcpu-functions.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/errh-add-err_ptr_pcpu-ptr_err_pcpu-and-is_err_pcpu-functions.patch
This patch will later appear in the mm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: Uros Bizjak <ubizjak@xxxxxxxxx>
Subject: err.h: add ERR_PTR_PCPU(), PTR_ERR_PCPU() and IS_ERR_PCPU() functions
Date: Tue, 13 Aug 2024 19:25:10 +0200
Add ERR_PTR_PCPU(), PTR_ERR_PCPU() and IS_ERR_PCPU() functions that
operate on pointers in the percpu address space.
These functions remove the need for (__force void *) function argument
casts (to avoid sparse -Wcast-from-as warnings).
The patch will also avoid future build errors due to pointer address space
mismatch with enabled strict percpu address space checks.
Link: https://lkml.kernel.org/r/20240813172543.38411-1-ubizjak@xxxxxxxxx
Signed-off-by: Uros Bizjak <ubizjak@xxxxxxxxx>
Cc: Catalin Marinas <catalin.marinas@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/linux/err.h | 38 ++++++++++++++++++++++++++++++++++++++
1 file changed, 38 insertions(+)
--- a/include/linux/err.h~errh-add-err_ptr_pcpu-ptr_err_pcpu-and-is_err_pcpu-functions
+++ a/include/linux/err.h
@@ -6,6 +6,7 @@
#include <linux/types.h>
#include <asm/errno.h>
+#include <asm/percpu.h>
/*
* Kernel pointers have redundant information, so we can use a
@@ -42,6 +43,22 @@ static inline void * __must_check ERR_PT
}
/**
+ * ERR_PTR_PCPU - Create an error pointer in the percpu address space.
+ * @error: A negative error code.
+ *
+ * Encodes @error into a pointer value in the percpu address space.
+ * Users should consider the result opaque and not assume anything
+ * about how the error is encoded.
+ *
+ * Return: A pointer in the percpu address space with @error encoded
+ * within its value.
+ */
+static inline void __percpu * __must_check ERR_PTR_PCPU(long error)
+{
+ return (void __percpu *) error;
+}
+
+/**
* PTR_ERR - Extract the error code from an error pointer.
* @ptr: An error pointer.
* Return: The error code within @ptr.
@@ -52,6 +69,17 @@ static inline long __must_check PTR_ERR(
}
/**
+ * PTR_ERR_PCPU - Extract the error code from an error pointer in the
+ * percpu address space.
+ * @ptr: An error pointer in the percpu address space.
+ * Return: The error code within @ptr.
+ */
+static inline long __must_check PTR_ERR_PCPU(const void __percpu *ptr)
+{
+ return (__force long) ptr;
+}
+
+/**
* IS_ERR - Detect an error pointer.
* @ptr: The pointer to check.
* Return: true if @ptr is an error pointer, false otherwise.
@@ -62,6 +90,16 @@ static inline bool __must_check IS_ERR(_
}
/**
+ * IS_ERR_PCPU - Detect an error pointer in the percpu address space.
+ * @ptr: The pointer in the percpu address space to check.
+ * Return: true if @ptr is an error pointer, false otherwise.
+ */
+static inline bool __must_check IS_ERR_PCPU(const void __percpu *ptr)
+{
+ return IS_ERR_VALUE((__force unsigned long)ptr);
+}
+
+/**
* IS_ERR_OR_NULL - Detect an error pointer or a null pointer.
* @ptr: The pointer to check.
*
_
Patches currently in -mm which might be from ubizjak@xxxxxxxxx are
mm-z3fold-add-__percpu-annotation-to-unbuddied-pointer-in-struct-z3fold_pool.patch
errh-add-err_ptr_pcpu-ptr_err_pcpu-and-is_err_pcpu-functions.patch
mm-kmemleak-use-is_err_pcpu-for-pointer-in-the-percpu-address-space.patch
kexec-use-atomic_try_cmpxchg_acquire-in-kexec_trylock.patch
