Hi Linus,
The following changes since commit c2f2b01b74be8b40a2173372bcd770723f87e7b2:
Merge tag 'i3c/for-6.19' of
git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linux (2025-12-08 11:25:14
+0900)
are available in the Git repository at:
git://git.kernel.org/pub/scm/linux/kernel/git/hpa/linux-auto.git
for you to fetch changes up to branch auto-type-for-6.19
(4ecc26fa585216f98d71411ce182f9e823d94c8c):
tools/virtio: replace "__auto_type" with "auto" (2025-12-08 15:32:15 -0800)
----------------------------------------------------------------
H. Peter Anvin (7):
compiler_types.h: add "auto" as a macro for "__auto_type"
include/linux: change "__auto_type" to "auto"
fs/proc: replace "__auto_type" with "const auto"
arch/nios2: replace "__auto_type" and adjacent equivalent with "auto"
arch/x86: replace "__auto_type" with "auto"
selftests/bpf: replace "__auto_type" with "auto"
tools/virtio: replace "__auto_type" with "auto"
arch/nios2/include/asm/uaccess.h | 8 ++++----
arch/x86/include/asm/bug.h | 2 +-
arch/x86/include/asm/string_64.h | 6 +++---
arch/x86/include/asm/uaccess_64.h | 2 +-
fs/proc/inode.c | 19 +++++++++----------
include/linux/cleanup.h | 6 +++---
include/linux/compiler.h | 2 +-
include/linux/compiler_types.h | 13 +++++++++++++
include/linux/minmax.h | 6 +++---
.../testing/selftests/bpf/prog_tests/socket_helpers.h | 9 +++++++--
tools/virtio/linux/compiler.h | 2 +-
11 files changed, 46 insertions(+), 29 deletions(-)
diff --git a/arch/nios2/include/asm/uaccess.h b/arch/nios2/include/asm/uaccess.h
index b8299082adbe..6ccc9a232c23 100644
--- a/arch/nios2/include/asm/uaccess.h
+++ b/arch/nios2/include/asm/uaccess.h
@@ -172,15 +172,15 @@ do {
\
#define __put_user(x, ptr) \
({ \
- __auto_type __pu_ptr = (ptr); \
- typeof(*__pu_ptr) __pu_val = (typeof(*__pu_ptr))(x); \
+ auto __pu_ptr = (ptr); \
+ auto __pu_val = (typeof(*__pu_ptr))(x); \
__put_user_common(__pu_val, __pu_ptr); \
})
#define put_user(x, ptr) \
({ \
- __auto_type __pu_ptr = (ptr); \
- typeof(*__pu_ptr) __pu_val = (typeof(*__pu_ptr))(x); \
+ auto __pu_ptr = (ptr); \
+ auto __pu_val = (typeof(*__pu_ptr))(x); \
access_ok(__pu_ptr, sizeof(*__pu_ptr)) ? \
__put_user_common(__pu_val, __pu_ptr) : \
-EFAULT; \
diff --git a/arch/x86/include/asm/bug.h b/arch/x86/include/asm/bug.h
index ee23b98353d7..d561a8443c13 100644
--- a/arch/x86/include/asm/bug.h
+++ b/arch/x86/include/asm/bug.h
@@ -129,7 +129,7 @@ do {
\
#define __WARN_FLAGS(cond_str, flags) \
do { \
- __auto_type __flags = BUGFLAG_WARNING|(flags); \
+ auto __flags = BUGFLAG_WARNING|(flags); \
instrumentation_begin(); \
_BUG_FLAGS(cond_str, ASM_UD2, __flags, ARCH_WARN_REACHABLE); \
instrumentation_end(); \
diff --git a/arch/x86/include/asm/string_64.h b/arch/x86/include/asm/string_64.h
index 79e9695dc13e..4635616863f5 100644
--- a/arch/x86/include/asm/string_64.h
+++ b/arch/x86/include/asm/string_64.h
@@ -31,7 +31,7 @@ KCFI_REFERENCE(__memset);
#define __HAVE_ARCH_MEMSET16
static inline void *memset16(uint16_t *s, uint16_t v, size_t n)
{
- const __auto_type s0 = s;
+ const auto s0 = s;
asm volatile (
"rep stosw"
: "+D" (s), "+c" (n)
@@ -44,7 +44,7 @@ static inline void *memset16(uint16_t *s, uint16_t v, size_t
n)
#define __HAVE_ARCH_MEMSET32
static inline void *memset32(uint32_t *s, uint32_t v, size_t n)
{
- const __auto_type s0 = s;
+ const auto s0 = s;
asm volatile (
"rep stosl"
: "+D" (s), "+c" (n)
@@ -57,7 +57,7 @@ static inline void *memset32(uint32_t *s, uint32_t v, size_t
n)
#define __HAVE_ARCH_MEMSET64
static inline void *memset64(uint64_t *s, uint64_t v, size_t n)
{
- const __auto_type s0 = s;
+ const auto s0 = s;
asm volatile (
"rep stosq"
: "+D" (s), "+c" (n)
diff --git a/arch/x86/include/asm/uaccess_64.h
b/arch/x86/include/asm/uaccess_64.h
index 641f45c22f9d..915124011c27 100644
--- a/arch/x86/include/asm/uaccess_64.h
+++ b/arch/x86/include/asm/uaccess_64.h
@@ -72,7 +72,7 @@ static inline void __user *mask_user_address(const void
__user *ptr)
return ret;
}
#define masked_user_access_begin(x) ({ \
- __auto_type __masked_ptr = (x); \
+ auto __masked_ptr = (x); \
__masked_ptr = mask_user_address(__masked_ptr); \
__uaccess_begin(); __masked_ptr; })
diff --git a/fs/proc/inode.c b/fs/proc/inode.c
index 2d3425cfa94b..b7634f975d98 100644
--- a/fs/proc/inode.c
+++ b/fs/proc/inode.c
@@ -303,7 +303,7 @@ static ssize_t proc_reg_read_iter(struct kiocb *iocb,
struct iov_iter *iter)
static ssize_t pde_read(struct proc_dir_entry *pde, struct file *file, char
__user *buf, size_t count, loff_t *ppos)
{
- __auto_type read = pde->proc_ops->proc_read;
+ const auto read = pde->proc_ops->proc_read;
if (read)
return read(file, buf, count, ppos);
return -EIO;
@@ -325,7 +325,7 @@ static ssize_t proc_reg_read(struct file *file, char __user
*buf, size_t count,
static ssize_t pde_write(struct proc_dir_entry *pde, struct file *file, const
char __user *buf, size_t count, loff_t *ppos)
{
- __auto_type write = pde->proc_ops->proc_write;
+ const auto write = pde->proc_ops->proc_write;
if (write)
return write(file, buf, count, ppos);
return -EIO;
@@ -347,7 +347,7 @@ static ssize_t proc_reg_write(struct file *file, const char
__user *buf, size_t
static __poll_t pde_poll(struct proc_dir_entry *pde, struct file *file, struct
poll_table_struct *pts)
{
- __auto_type poll = pde->proc_ops->proc_poll;
+ const auto poll = pde->proc_ops->proc_poll;
if (poll)
return poll(file, pts);
return DEFAULT_POLLMASK;
@@ -369,7 +369,7 @@ static __poll_t proc_reg_poll(struct file *file, struct
poll_table_struct *pts)
static long pde_ioctl(struct proc_dir_entry *pde, struct file *file, unsigned
int cmd, unsigned long arg)
{
- __auto_type ioctl = pde->proc_ops->proc_ioctl;
+ const auto ioctl = pde->proc_ops->proc_ioctl;
if (ioctl)
return ioctl(file, cmd, arg);
return -ENOTTY;
@@ -392,7 +392,7 @@ static long proc_reg_unlocked_ioctl(struct file *file,
unsigned int cmd, unsigne
#ifdef CONFIG_COMPAT
static long pde_compat_ioctl(struct proc_dir_entry *pde, struct file *file,
unsigned int cmd, unsigned long arg)
{
- __auto_type compat_ioctl = pde->proc_ops->proc_compat_ioctl;
+ const auto compat_ioctl = pde->proc_ops->proc_compat_ioctl;
if (compat_ioctl)
return compat_ioctl(file, cmd, arg);
return -ENOTTY;
@@ -414,7 +414,7 @@ static long proc_reg_compat_ioctl(struct file *file,
unsigned int cmd, unsigned
static int pde_mmap(struct proc_dir_entry *pde, struct file *file, struct
vm_area_struct *vma)
{
- __auto_type mmap = pde->proc_ops->proc_mmap;
+ const auto mmap = pde->proc_ops->proc_mmap;
if (mmap)
return mmap(file, vma);
return -EIO;
@@ -497,7 +497,7 @@ static int proc_reg_open(struct inode *inode, struct file
*file)
if (!use_pde(pde))
return -ENOENT;
- __auto_type release = pde->proc_ops->proc_release;
+ const auto release = pde->proc_ops->proc_release;
if (release) {
pdeo = kmem_cache_alloc(pde_opener_cache, GFP_KERNEL);
if (!pdeo) {
@@ -534,10 +534,9 @@ static int proc_reg_release(struct inode *inode, struct
file *file)
struct pde_opener *pdeo;
if (pde_is_permanent(pde)) {
- __auto_type release = pde->proc_ops->proc_release;
- if (release) {
+ const auto release = pde->proc_ops->proc_release;
+ if (release)
return release(inode, file);
- }
return 0;
}
diff --git a/include/linux/cleanup.h b/include/linux/cleanup.h
index 0b55a8f6c59e..8d41b917c77d 100644
--- a/include/linux/cleanup.h
+++ b/include/linux/cleanup.h
@@ -212,10 +212,10 @@
#define __free(_name) __cleanup(__free_##_name)
-#define __get_and_null(p, nullvalue) \
+#define __get_and_null(p, nullvalue) \
({ \
- __auto_type __ptr = &(p); \
- __auto_type __val = *__ptr; \
+ auto __ptr = &(p); \
+ auto __val = *__ptr; \
*__ptr = nullvalue; \
__val; \
})
diff --git a/include/linux/compiler.h b/include/linux/compiler.h
index ff71bebe56f5..04487c9bd751 100644
--- a/include/linux/compiler.h
+++ b/include/linux/compiler.h
@@ -190,7 +190,7 @@ void ftrace_likely_update(struct ftrace_likely_data *f, int
val,
#define data_race(expr)
\
({ \
__kcsan_disable_current(); \
- __auto_type __v = (expr); \
+ auto __v = (expr); \
__kcsan_enable_current(); \
__v; \
})
diff --git a/include/linux/compiler_types.h b/include/linux/compiler_types.h
index 3eac51d68426..41172a28ce76 100644
--- a/include/linux/compiler_types.h
+++ b/include/linux/compiler_types.h
@@ -13,6 +13,19 @@
#ifndef __ASSEMBLY__
+/*
+ * C23 introduces "auto" as a standard way to define type-inferred
+ * variables, but "auto" has been a (useless) keyword even since K&R C,
+ * so it has always been "namespace reserved."
+ *
+ * Until at some future time we require C23 support, we need the gcc
+ * extension __auto_type, but there is no reason to put that elsewhere
+ * in the source code.
+ */
+#if __STDC_VERSION__ < 202311L
+# define auto __auto_type
+#endif
+
/*
* Skipped when running bindgen due to a libclang issue;
* see https://github.com/rust-lang/rust-bindgen/issues/2244.
diff --git a/include/linux/minmax.h b/include/linux/minmax.h
index eaaf5c008e4d..a0158db54a04 100644
--- a/include/linux/minmax.h
+++ b/include/linux/minmax.h
@@ -89,7 +89,7 @@
__cmp_once_unique(op, type, x, y, __UNIQUE_ID(x_), __UNIQUE_ID(y_))
#define __careful_cmp_once(op, x, y, ux, uy) ({ \
- __auto_type ux = (x); __auto_type uy = (y); \
+ auto ux = (x); auto uy = (y); \
BUILD_BUG_ON_MSG(!__types_ok(ux, uy), \
#op"("#x", "#y") signedness error"); \
__cmp(op, ux, uy); })
@@ -129,7 +129,7 @@
__careful_cmp(max, (x) + 0u + 0ul + 0ull, (y) + 0u + 0ul + 0ull)
#define __careful_op3(op, x, y, z, ux, uy, uz) ({ \
- __auto_type ux = (x); __auto_type uy = (y);__auto_type uz = (z);\
+ auto ux = (x); auto uy = (y); auto uz = (z); \
BUILD_BUG_ON_MSG(!__types_ok3(ux, uy, uz), \
#op"3("#x", "#y", "#z") signedness error"); \
__cmp(op, ux, __cmp(op, uy, uz)); })
@@ -203,7 +203,7 @@
* This macro checks @val/@lo/@hi to make sure they have compatible
* signedness.
*/
-#define clamp(val, lo, hi) __careful_clamp(__auto_type, val, lo, hi)
+#define clamp(val, lo, hi) __careful_clamp(auto, val, lo, hi)
/**
* clamp_t - return a value clamped to a given range using a given type
diff --git a/tools/testing/selftests/bpf/prog_tests/socket_helpers.h
b/tools/testing/selftests/bpf/prog_tests/socket_helpers.h
index e02cabcc814e..0d59503a0c73 100644
--- a/tools/testing/selftests/bpf/prog_tests/socket_helpers.h
+++ b/tools/testing/selftests/bpf/prog_tests/socket_helpers.h
@@ -17,11 +17,16 @@
#define VMADDR_CID_LOCAL 1
#endif
+/* include/linux/compiler_types.h */
+#if __STDC_VERSION__ < 202311L && !defined(auto)
+# define auto __auto_type
+#endif
+
/* include/linux/cleanup.h */
#define __get_and_null(p, nullvalue)
\
({ \
- __auto_type __ptr = &(p); \
- __auto_type __val = *__ptr; \
+ auto __ptr = &(p); \
+ auto __val = *__ptr; \
*__ptr = nullvalue; \
__val; \
})
diff --git a/tools/virtio/linux/compiler.h b/tools/virtio/linux/compiler.h
index 204ef0e9f542..725b93bfeee1 100644
--- a/tools/virtio/linux/compiler.h
+++ b/tools/virtio/linux/compiler.h
@@ -31,7 +31,7 @@
*/
#define data_race(expr)
\
({ \
- __auto_type __v = (expr); \
+ auto __v = (expr); \
__v; \
})
