| Message ID | e9b1ba517f06b81bd24e54c84f5e44d81c27c566.camel@perches.com (mailing list archive) |
|---|---|
| State | Not Applicable |
| Delegated to: | Herbert Xu |
| Headers | show |
| Series | [-next] treewide: Remove stringification from __alias macro definition | expand |
On Wed, 21 Oct 2020 at 20:58, Joe Perches <joe@perches.com> wrote: > > Like the __section macro, the __alias macro uses > macro # stringification to create quotes around > the section name used in the __attribute__. > > Remove the stringification and add quotes or a > stringification to the uses instead. > Why? > Signed-off-by: Joe Perches <joe@perches.com> > --- > > There is a script that might eventually be applied > to convert the __section macro definition and uses > to remove stringification > > https://lore.kernel.org/lkml/46f69161e60b802488ba8c8f3f8bbf922aa3b49b.camel@perches.com/ > https://lore.kernel.org/lkml/75393e5ddc272dc7403de74d645e6c6e0f4e70eb.camel@perches.com/ > > This patch is intended to create commonality > between the uses of __section and __alias. > > arch/x86/boot/compressed/string.c | 6 +++--- > arch/x86/include/asm/syscall_wrapper.h | 2 +- > drivers/firmware/efi/runtime-wrappers.c | 2 +- > include/linux/compiler_attributes.h | 2 +- > kernel/kcsan/core.c | 10 +++++----- > lib/crc32.c | 4 ++-- > lib/crypto/aes.c | 4 ++-- > mm/kasan/generic.c | 8 ++++---- > 8 files changed, 19 insertions(+), 19 deletions(-) > > diff --git a/arch/x86/boot/compressed/string.c b/arch/x86/boot/compressed/string.c > index 81fc1eaa3229..d38b122f51ef 100644 > --- a/arch/x86/boot/compressed/string.c > +++ b/arch/x86/boot/compressed/string.c > @@ -75,7 +75,7 @@ void *memcpy(void *dest, const void *src, size_t n) > } > > #ifdef CONFIG_KASAN > -extern void *__memset(void *s, int c, size_t n) __alias(memset); > -extern void *__memmove(void *dest, const void *src, size_t n) __alias(memmove); > -extern void *__memcpy(void *dest, const void *src, size_t n) __alias(memcpy); > +extern void *__memset(void *s, int c, size_t n) __alias("memset"); > +extern void *__memmove(void *dest, const void *src, size_t n) __alias("memmove"); > +extern void *__memcpy(void *dest, const void *src, size_t n) __alias("memcpy"); > #endif > diff --git a/arch/x86/include/asm/syscall_wrapper.h b/arch/x86/include/asm/syscall_wrapper.h > index a84333adeef2..f19d1bbbff3d 100644 > --- a/arch/x86/include/asm/syscall_wrapper.h > +++ b/arch/x86/include/asm/syscall_wrapper.h > @@ -69,7 +69,7 @@ extern long __ia32_sys_ni_syscall(const struct pt_regs *regs); > long __##abi##_##name(const struct pt_regs *regs); \ > ALLOW_ERROR_INJECTION(__##abi##_##name, ERRNO); \ > long __##abi##_##name(const struct pt_regs *regs) \ > - __alias(__do_##name); > + __alias("__do_" #name); > > #define __SYS_STUBx(abi, name, ...) \ > long __##abi##_##name(const struct pt_regs *regs); \ > diff --git a/drivers/firmware/efi/runtime-wrappers.c b/drivers/firmware/efi/runtime-wrappers.c > index 1410beaef5c3..14e380ac65d4 100644 > --- a/drivers/firmware/efi/runtime-wrappers.c > +++ b/drivers/firmware/efi/runtime-wrappers.c > @@ -162,7 +162,7 @@ static DEFINE_SEMAPHORE(efi_runtime_lock); > * Expose the EFI runtime lock to the UV platform > */ > #ifdef CONFIG_X86_UV > -extern struct semaphore __efi_uv_runtime_lock __alias(efi_runtime_lock); > +extern struct semaphore __efi_uv_runtime_lock __alias("efi_runtime_lock"); > #endif > > /* > diff --git a/include/linux/compiler_attributes.h b/include/linux/compiler_attributes.h > index ea7b756b1c8f..4819512c9abd 100644 > --- a/include/linux/compiler_attributes.h > +++ b/include/linux/compiler_attributes.h > @@ -42,7 +42,7 @@ > /* > * gcc: https://gcc.gnu.org/onlinedocs/gcc/Common-Function-Attributes.html#index-alias-function-attribute > */ > -#define __alias(symbol) __attribute__((__alias__(#symbol))) > +#define __alias(symbol) __attribute__((__alias__(symbol))) > > /* > * gcc: https://gcc.gnu.org/onlinedocs/gcc/Common-Function-Attributes.html#index-aligned-function-attribute > diff --git a/kernel/kcsan/core.c b/kernel/kcsan/core.c > index 3994a217bde7..465f6cfc317c 100644 > --- a/kernel/kcsan/core.c > +++ b/kernel/kcsan/core.c > @@ -814,7 +814,7 @@ EXPORT_SYMBOL(__kcsan_check_access); > } \ > EXPORT_SYMBOL(__tsan_read##size); \ > void __tsan_unaligned_read##size(void *ptr) \ > - __alias(__tsan_read##size); \ > + __alias("__tsan_read" #size); \ > EXPORT_SYMBOL(__tsan_unaligned_read##size); \ > void __tsan_write##size(void *ptr); \ > void __tsan_write##size(void *ptr) \ > @@ -823,7 +823,7 @@ EXPORT_SYMBOL(__kcsan_check_access); > } \ > EXPORT_SYMBOL(__tsan_write##size); \ > void __tsan_unaligned_write##size(void *ptr) \ > - __alias(__tsan_write##size); \ > + __alias("__tsan_write" #size); \ > EXPORT_SYMBOL(__tsan_unaligned_write##size); \ > void __tsan_read_write##size(void *ptr); \ > void __tsan_read_write##size(void *ptr) \ > @@ -833,7 +833,7 @@ EXPORT_SYMBOL(__kcsan_check_access); > } \ > EXPORT_SYMBOL(__tsan_read_write##size); \ > void __tsan_unaligned_read_write##size(void *ptr) \ > - __alias(__tsan_read_write##size); \ > + __alias("__tsan_read_write" #size); \ > EXPORT_SYMBOL(__tsan_unaligned_read_write##size) > > DEFINE_TSAN_READ_WRITE(1); > @@ -877,7 +877,7 @@ EXPORT_SYMBOL(__tsan_write_range); > } \ > EXPORT_SYMBOL(__tsan_volatile_read##size); \ > void __tsan_unaligned_volatile_read##size(void *ptr) \ > - __alias(__tsan_volatile_read##size); \ > + __alias("__tsan_volatile_read" #size); \ > EXPORT_SYMBOL(__tsan_unaligned_volatile_read##size); \ > void __tsan_volatile_write##size(void *ptr); \ > void __tsan_volatile_write##size(void *ptr) \ > @@ -892,7 +892,7 @@ EXPORT_SYMBOL(__tsan_write_range); > } \ > EXPORT_SYMBOL(__tsan_volatile_write##size); \ > void __tsan_unaligned_volatile_write##size(void *ptr) \ > - __alias(__tsan_volatile_write##size); \ > + __alias("__tsan_volatile_write" #size); \ > EXPORT_SYMBOL(__tsan_unaligned_volatile_write##size) > > DEFINE_TSAN_VOLATILE_READ_WRITE(1); > diff --git a/lib/crc32.c b/lib/crc32.c > index 2a68dfd3b96c..373a17aaa432 100644 > --- a/lib/crc32.c > +++ b/lib/crc32.c > @@ -206,8 +206,8 @@ u32 __pure __weak __crc32c_le(u32 crc, unsigned char const *p, size_t len) > EXPORT_SYMBOL(crc32_le); > EXPORT_SYMBOL(__crc32c_le); > > -u32 __pure crc32_le_base(u32, unsigned char const *, size_t) __alias(crc32_le); > -u32 __pure __crc32c_le_base(u32, unsigned char const *, size_t) __alias(__crc32c_le); > +u32 __pure crc32_le_base(u32, unsigned char const *, size_t) __alias("crc32_le"); > +u32 __pure __crc32c_le_base(u32, unsigned char const *, size_t) __alias("__crc32c_le"); > > /* > * This multiplies the polynomials x and y modulo the given modulus. > diff --git a/lib/crypto/aes.c b/lib/crypto/aes.c > index 827fe89922ff..5b80514595c2 100644 > --- a/lib/crypto/aes.c > +++ b/lib/crypto/aes.c > @@ -82,8 +82,8 @@ static volatile const u8 __cacheline_aligned aes_inv_sbox[] = { > 0xe1, 0x69, 0x14, 0x63, 0x55, 0x21, 0x0c, 0x7d, > }; > > -extern const u8 crypto_aes_sbox[256] __alias(aes_sbox); > -extern const u8 crypto_aes_inv_sbox[256] __alias(aes_inv_sbox); > +extern const u8 crypto_aes_sbox[256] __alias("aes_sbox"); > +extern const u8 crypto_aes_inv_sbox[256] __alias("aes_inv_sbox"); > > EXPORT_SYMBOL(crypto_aes_sbox); > EXPORT_SYMBOL(crypto_aes_inv_sbox); > diff --git a/mm/kasan/generic.c b/mm/kasan/generic.c > index 248264b9cb76..4496f897e4f5 100644 > --- a/mm/kasan/generic.c > +++ b/mm/kasan/generic.c > @@ -234,7 +234,7 @@ EXPORT_SYMBOL(__asan_unregister_globals); > check_memory_region_inline(addr, size, false, _RET_IP_);\ > } \ > EXPORT_SYMBOL(__asan_load##size); \ > - __alias(__asan_load##size) \ > + __alias("__asan_load" #size) \ > void __asan_load##size##_noabort(unsigned long); \ > EXPORT_SYMBOL(__asan_load##size##_noabort); \ > void __asan_store##size(unsigned long addr) \ > @@ -242,7 +242,7 @@ EXPORT_SYMBOL(__asan_unregister_globals); > check_memory_region_inline(addr, size, true, _RET_IP_); \ > } \ > EXPORT_SYMBOL(__asan_store##size); \ > - __alias(__asan_store##size) \ > + __alias("__asan_store" #size) \ > void __asan_store##size##_noabort(unsigned long); \ > EXPORT_SYMBOL(__asan_store##size##_noabort) > > @@ -258,7 +258,7 @@ void __asan_loadN(unsigned long addr, size_t size) > } > EXPORT_SYMBOL(__asan_loadN); > > -__alias(__asan_loadN) > +__alias("__asan_loadN") > void __asan_loadN_noabort(unsigned long, size_t); > EXPORT_SYMBOL(__asan_loadN_noabort); > > @@ -268,7 +268,7 @@ void __asan_storeN(unsigned long addr, size_t size) > } > EXPORT_SYMBOL(__asan_storeN); > > -__alias(__asan_storeN) > +__alias("__asan_storeN") > void __asan_storeN_noabort(unsigned long, size_t); > EXPORT_SYMBOL(__asan_storeN_noabort); > > > > >
On Wed, 2020-10-21 at 21:02 +0200, Ard Biesheuvel wrote: > On Wed, 21 Oct 2020 at 20:58, Joe Perches <joe@perches.com> wrote: > > Like the __section macro, the __alias macro uses > > macro # stringification to create quotes around > > the section name used in the __attribute__. > > > > Remove the stringification and add quotes or a > > stringification to the uses instead. > > > > Why? Using quotes in __section caused/causes differences between clang and gcc. https://lkml.org/lkml/2020/9/29/2187 Using common styles for details like this is good.
On Wed, 21 Oct 2020 at 21:07, Joe Perches <joe@perches.com> wrote: > > On Wed, 2020-10-21 at 21:02 +0200, Ard Biesheuvel wrote: > > On Wed, 21 Oct 2020 at 20:58, Joe Perches <joe@perches.com> wrote: > > > Like the __section macro, the __alias macro uses > > > macro # stringification to create quotes around > > > the section name used in the __attribute__. > > > > > > Remove the stringification and add quotes or a > > > stringification to the uses instead. > > > > > > > Why? > > Using quotes in __section caused/causes differences > between clang and gcc. > > https://lkml.org/lkml/2020/9/29/2187 > > Using common styles for details like this is good. > > Ah, fair enough. With this rationale added to the commit log: Acked-by: Ard Biesheuvel <ardb@kernel.org>
On Wed, 21 Oct 2020 at 20:58, Joe Perches <joe@perches.com> wrote: > > Like the __section macro, the __alias macro uses > macro # stringification to create quotes around > the section name used in the __attribute__. > > Remove the stringification and add quotes or a > stringification to the uses instead. > > Signed-off-by: Joe Perches <joe@perches.com> > --- > > There is a script that might eventually be applied > to convert the __section macro definition and uses > to remove stringification > > https://lore.kernel.org/lkml/46f69161e60b802488ba8c8f3f8bbf922aa3b49b.camel@perches.com/ > https://lore.kernel.org/lkml/75393e5ddc272dc7403de74d645e6c6e0f4e70eb.camel@perches.com/ > > This patch is intended to create commonality > between the uses of __section and __alias. > > arch/x86/boot/compressed/string.c | 6 +++--- > arch/x86/include/asm/syscall_wrapper.h | 2 +- > drivers/firmware/efi/runtime-wrappers.c | 2 +- > include/linux/compiler_attributes.h | 2 +- > kernel/kcsan/core.c | 10 +++++----- > lib/crc32.c | 4 ++-- > lib/crypto/aes.c | 4 ++-- > mm/kasan/generic.c | 8 ++++---- > 8 files changed, 19 insertions(+), 19 deletions(-) Reviewed-by: Marco Elver <elver@google.com> for KCSAN and KASAN. Thank you! > diff --git a/arch/x86/boot/compressed/string.c b/arch/x86/boot/compressed/string.c > index 81fc1eaa3229..d38b122f51ef 100644 > --- a/arch/x86/boot/compressed/string.c > +++ b/arch/x86/boot/compressed/string.c > @@ -75,7 +75,7 @@ void *memcpy(void *dest, const void *src, size_t n) > } > > #ifdef CONFIG_KASAN > -extern void *__memset(void *s, int c, size_t n) __alias(memset); > -extern void *__memmove(void *dest, const void *src, size_t n) __alias(memmove); > -extern void *__memcpy(void *dest, const void *src, size_t n) __alias(memcpy); > +extern void *__memset(void *s, int c, size_t n) __alias("memset"); > +extern void *__memmove(void *dest, const void *src, size_t n) __alias("memmove"); > +extern void *__memcpy(void *dest, const void *src, size_t n) __alias("memcpy"); > #endif > diff --git a/arch/x86/include/asm/syscall_wrapper.h b/arch/x86/include/asm/syscall_wrapper.h > index a84333adeef2..f19d1bbbff3d 100644 > --- a/arch/x86/include/asm/syscall_wrapper.h > +++ b/arch/x86/include/asm/syscall_wrapper.h > @@ -69,7 +69,7 @@ extern long __ia32_sys_ni_syscall(const struct pt_regs *regs); > long __##abi##_##name(const struct pt_regs *regs); \ > ALLOW_ERROR_INJECTION(__##abi##_##name, ERRNO); \ > long __##abi##_##name(const struct pt_regs *regs) \ > - __alias(__do_##name); > + __alias("__do_" #name); > > #define __SYS_STUBx(abi, name, ...) \ > long __##abi##_##name(const struct pt_regs *regs); \ > diff --git a/drivers/firmware/efi/runtime-wrappers.c b/drivers/firmware/efi/runtime-wrappers.c > index 1410beaef5c3..14e380ac65d4 100644 > --- a/drivers/firmware/efi/runtime-wrappers.c > +++ b/drivers/firmware/efi/runtime-wrappers.c > @@ -162,7 +162,7 @@ static DEFINE_SEMAPHORE(efi_runtime_lock); > * Expose the EFI runtime lock to the UV platform > */ > #ifdef CONFIG_X86_UV > -extern struct semaphore __efi_uv_runtime_lock __alias(efi_runtime_lock); > +extern struct semaphore __efi_uv_runtime_lock __alias("efi_runtime_lock"); > #endif > > /* > diff --git a/include/linux/compiler_attributes.h b/include/linux/compiler_attributes.h > index ea7b756b1c8f..4819512c9abd 100644 > --- a/include/linux/compiler_attributes.h > +++ b/include/linux/compiler_attributes.h > @@ -42,7 +42,7 @@ > /* > * gcc: https://gcc.gnu.org/onlinedocs/gcc/Common-Function-Attributes.html#index-alias-function-attribute > */ > -#define __alias(symbol) __attribute__((__alias__(#symbol))) > +#define __alias(symbol) __attribute__((__alias__(symbol))) > > /* > * gcc: https://gcc.gnu.org/onlinedocs/gcc/Common-Function-Attributes.html#index-aligned-function-attribute > diff --git a/kernel/kcsan/core.c b/kernel/kcsan/core.c > index 3994a217bde7..465f6cfc317c 100644 > --- a/kernel/kcsan/core.c > +++ b/kernel/kcsan/core.c > @@ -814,7 +814,7 @@ EXPORT_SYMBOL(__kcsan_check_access); > } \ > EXPORT_SYMBOL(__tsan_read##size); \ > void __tsan_unaligned_read##size(void *ptr) \ > - __alias(__tsan_read##size); \ > + __alias("__tsan_read" #size); \ > EXPORT_SYMBOL(__tsan_unaligned_read##size); \ > void __tsan_write##size(void *ptr); \ > void __tsan_write##size(void *ptr) \ > @@ -823,7 +823,7 @@ EXPORT_SYMBOL(__kcsan_check_access); > } \ > EXPORT_SYMBOL(__tsan_write##size); \ > void __tsan_unaligned_write##size(void *ptr) \ > - __alias(__tsan_write##size); \ > + __alias("__tsan_write" #size); \ > EXPORT_SYMBOL(__tsan_unaligned_write##size); \ > void __tsan_read_write##size(void *ptr); \ > void __tsan_read_write##size(void *ptr) \ > @@ -833,7 +833,7 @@ EXPORT_SYMBOL(__kcsan_check_access); > } \ > EXPORT_SYMBOL(__tsan_read_write##size); \ > void __tsan_unaligned_read_write##size(void *ptr) \ > - __alias(__tsan_read_write##size); \ > + __alias("__tsan_read_write" #size); \ > EXPORT_SYMBOL(__tsan_unaligned_read_write##size) > > DEFINE_TSAN_READ_WRITE(1); > @@ -877,7 +877,7 @@ EXPORT_SYMBOL(__tsan_write_range); > } \ > EXPORT_SYMBOL(__tsan_volatile_read##size); \ > void __tsan_unaligned_volatile_read##size(void *ptr) \ > - __alias(__tsan_volatile_read##size); \ > + __alias("__tsan_volatile_read" #size); \ > EXPORT_SYMBOL(__tsan_unaligned_volatile_read##size); \ > void __tsan_volatile_write##size(void *ptr); \ > void __tsan_volatile_write##size(void *ptr) \ > @@ -892,7 +892,7 @@ EXPORT_SYMBOL(__tsan_write_range); > } \ > EXPORT_SYMBOL(__tsan_volatile_write##size); \ > void __tsan_unaligned_volatile_write##size(void *ptr) \ > - __alias(__tsan_volatile_write##size); \ > + __alias("__tsan_volatile_write" #size); \ > EXPORT_SYMBOL(__tsan_unaligned_volatile_write##size) > > DEFINE_TSAN_VOLATILE_READ_WRITE(1); > diff --git a/lib/crc32.c b/lib/crc32.c > index 2a68dfd3b96c..373a17aaa432 100644 > --- a/lib/crc32.c > +++ b/lib/crc32.c > @@ -206,8 +206,8 @@ u32 __pure __weak __crc32c_le(u32 crc, unsigned char const *p, size_t len) > EXPORT_SYMBOL(crc32_le); > EXPORT_SYMBOL(__crc32c_le); > > -u32 __pure crc32_le_base(u32, unsigned char const *, size_t) __alias(crc32_le); > -u32 __pure __crc32c_le_base(u32, unsigned char const *, size_t) __alias(__crc32c_le); > +u32 __pure crc32_le_base(u32, unsigned char const *, size_t) __alias("crc32_le"); > +u32 __pure __crc32c_le_base(u32, unsigned char const *, size_t) __alias("__crc32c_le"); > > /* > * This multiplies the polynomials x and y modulo the given modulus. > diff --git a/lib/crypto/aes.c b/lib/crypto/aes.c > index 827fe89922ff..5b80514595c2 100644 > --- a/lib/crypto/aes.c > +++ b/lib/crypto/aes.c > @@ -82,8 +82,8 @@ static volatile const u8 __cacheline_aligned aes_inv_sbox[] = { > 0xe1, 0x69, 0x14, 0x63, 0x55, 0x21, 0x0c, 0x7d, > }; > > -extern const u8 crypto_aes_sbox[256] __alias(aes_sbox); > -extern const u8 crypto_aes_inv_sbox[256] __alias(aes_inv_sbox); > +extern const u8 crypto_aes_sbox[256] __alias("aes_sbox"); > +extern const u8 crypto_aes_inv_sbox[256] __alias("aes_inv_sbox"); > > EXPORT_SYMBOL(crypto_aes_sbox); > EXPORT_SYMBOL(crypto_aes_inv_sbox); > diff --git a/mm/kasan/generic.c b/mm/kasan/generic.c > index 248264b9cb76..4496f897e4f5 100644 > --- a/mm/kasan/generic.c > +++ b/mm/kasan/generic.c > @@ -234,7 +234,7 @@ EXPORT_SYMBOL(__asan_unregister_globals); > check_memory_region_inline(addr, size, false, _RET_IP_);\ > } \ > EXPORT_SYMBOL(__asan_load##size); \ > - __alias(__asan_load##size) \ > + __alias("__asan_load" #size) \ > void __asan_load##size##_noabort(unsigned long); \ > EXPORT_SYMBOL(__asan_load##size##_noabort); \ > void __asan_store##size(unsigned long addr) \ > @@ -242,7 +242,7 @@ EXPORT_SYMBOL(__asan_unregister_globals); > check_memory_region_inline(addr, size, true, _RET_IP_); \ > } \ > EXPORT_SYMBOL(__asan_store##size); \ > - __alias(__asan_store##size) \ > + __alias("__asan_store" #size) \ > void __asan_store##size##_noabort(unsigned long); \ > EXPORT_SYMBOL(__asan_store##size##_noabort) > > @@ -258,7 +258,7 @@ void __asan_loadN(unsigned long addr, size_t size) > } > EXPORT_SYMBOL(__asan_loadN); > > -__alias(__asan_loadN) > +__alias("__asan_loadN") > void __asan_loadN_noabort(unsigned long, size_t); > EXPORT_SYMBOL(__asan_loadN_noabort); > > @@ -268,7 +268,7 @@ void __asan_storeN(unsigned long addr, size_t size) > } > EXPORT_SYMBOL(__asan_storeN); > > -__alias(__asan_storeN) > +__alias("__asan_storeN") > void __asan_storeN_noabort(unsigned long, size_t); > EXPORT_SYMBOL(__asan_storeN_noabort); > > > > >
On Wed, Oct 21, 2020 at 9:07 PM Joe Perches <joe@perches.com> wrote: > > Using quotes in __section caused/causes differences > between clang and gcc. Yeah, it is a good cleanup get. Thanks! > https://lkml.org/lkml/2020/9/29/2187 Can you please put this in a Link: like Ard suggested? (and ideally find the message in lore.kernel.org instead). Cheers, Miguel
On Wed, Oct 21, 2020 at 12:07 PM Joe Perches <joe@perches.com> wrote: > > On Wed, 2020-10-21 at 21:02 +0200, Ard Biesheuvel wrote: > > On Wed, 21 Oct 2020 at 20:58, Joe Perches <joe@perches.com> wrote: > > > Like the __section macro, the __alias macro uses > > > macro # stringification to create quotes around > > > the section name used in the __attribute__. > > > > > > Remove the stringification and add quotes or a > > > stringification to the uses instead. > > > > > > > Why? > > Using quotes in __section caused/causes differences > between clang and gcc. > > https://lkml.org/lkml/2020/9/29/2187 > > Using common styles for details like this is good. Luckily, there's no difference/issue here with alias as there exist with section: https://godbolt.org/z/eWxc7P So it's just a stylistic cleanup, not a bugfix. Acked-by: Nick Desaulniers <ndesaulniers@google.com> $ grep -rn __attribute__ | grep alias didn't turn up any other cases that look like they don't use strings.
From: Ard Biesheuvel > Sent: 21 October 2020 20:03 > > On Wed, 21 Oct 2020 at 20:58, Joe Perches <joe@perches.com> wrote: > > > > Like the __section macro, the __alias macro uses > > macro # stringification to create quotes around > > the section name used in the __attribute__. > > > > Remove the stringification and add quotes or a > > stringification to the uses instead. > > > > Why? It allows the section name be made up of two concatenated strings. David - Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK Registration No: 1397386 (Wales)
On Wed, Oct 21, 2020 at 11:58:25AM -0700, Joe Perches wrote: > Like the __section macro, the __alias macro uses > macro # stringification to create quotes around > the section name used in the __attribute__. > > Remove the stringification and add quotes or a > stringification to the uses instead. There's a complete lack of rationale for this change.
On Thu, 2020-10-22 at 09:33 +0200, Peter Zijlstra wrote: > On Wed, Oct 21, 2020 at 11:58:25AM -0700, Joe Perches wrote: > > Like the __section macro, the __alias macro uses > > macro # stringification to create quotes around > > the section name used in the __attribute__. > > > > Remove the stringification and add quotes or a > > stringification to the uses instead. > > There's a complete lack of rationale for this change. I'll eventually post V2. I'm waiting to see if there are more comments. As I wrote in reply to Ard: https://lore.kernel.org/lkml/1cecfbfc853b2e71a96ab58661037c28a2f9280e.camel@perches.com/ Using quotes in __section caused/causes differences between clang and gcc. https://lkml.org/lkml/2020/9/29/2187 Using common styles for details like this is good.
(+ Russell) On Thu, 22 Oct 2020 at 18:20, Joe Perches <joe@perches.com> wrote: > > On Thu, 2020-10-22 at 09:33 +0200, Peter Zijlstra wrote: > > On Wed, Oct 21, 2020 at 11:58:25AM -0700, Joe Perches wrote: > > > Like the __section macro, the __alias macro uses > > > macro # stringification to create quotes around > > > the section name used in the __attribute__. > > > > > > Remove the stringification and add quotes or a > > > stringification to the uses instead. > > > > There's a complete lack of rationale for this change. > > I'll eventually post V2. > I'm waiting to see if there are more comments. > > As I wrote in reply to Ard: > > https://lore.kernel.org/lkml/1cecfbfc853b2e71a96ab58661037c28a2f9280e.camel@perches.com/ > > Using quotes in __section caused/causes differences > between clang and gcc. > > https://lkml.org/lkml/2020/9/29/2187 > > Using common styles for details like this is good. > This patch is now causing problems in the ARM tree, because some new uses of __alias() have been queued (for KASAN), and since this is a non-backwards compatible change, we have to choose between breaking the maintainer's tree or breaking -next (given that the change has been pulled in there now) I am still not convinced we need this change, as I don't see how the concerns regarding __section apply to __alias. But if we do, can we please use the same approach, i.e., revert the current patch, and queue it again after v5.11-rc1 with all new occurrences covered as well?
On Wed, Nov 11, 2020 at 8:19 AM Ard Biesheuvel <ardb@kernel.org> wrote: > > I am still not convinced we need this change, as I don't see how the > concerns regarding __section apply to __alias. But if we do, can we > please use the same approach, i.e., revert the current patch, and > queue it again after v5.11-rc1 with all new occurrences covered as > well? In general, it would be nice to move all compiler attributes to use the `__` syntax, which is independent of compiler vendor, gives us a level of indirection to modify behavior between compilers and is shorter/nicer for users. But it is low priority, so it should go in whenever it causes the least amount of trouble. Cheers, Miguel
diff --git a/arch/x86/boot/compressed/string.c b/arch/x86/boot/compressed/string.c index 81fc1eaa3229..d38b122f51ef 100644 --- a/arch/x86/boot/compressed/string.c +++ b/arch/x86/boot/compressed/string.c @@ -75,7 +75,7 @@ void *memcpy(void *dest, const void *src, size_t n) } #ifdef CONFIG_KASAN -extern void *__memset(void *s, int c, size_t n) __alias(memset); -extern void *__memmove(void *dest, const void *src, size_t n) __alias(memmove); -extern void *__memcpy(void *dest, const void *src, size_t n) __alias(memcpy); +extern void *__memset(void *s, int c, size_t n) __alias("memset"); +extern void *__memmove(void *dest, const void *src, size_t n) __alias("memmove"); +extern void *__memcpy(void *dest, const void *src, size_t n) __alias("memcpy"); #endif diff --git a/arch/x86/include/asm/syscall_wrapper.h b/arch/x86/include/asm/syscall_wrapper.h index a84333adeef2..f19d1bbbff3d 100644 --- a/arch/x86/include/asm/syscall_wrapper.h +++ b/arch/x86/include/asm/syscall_wrapper.h @@ -69,7 +69,7 @@ extern long __ia32_sys_ni_syscall(const struct pt_regs *regs); long __##abi##_##name(const struct pt_regs *regs); \ ALLOW_ERROR_INJECTION(__##abi##_##name, ERRNO); \ long __##abi##_##name(const struct pt_regs *regs) \ - __alias(__do_##name); + __alias("__do_" #name); #define __SYS_STUBx(abi, name, ...) \ long __##abi##_##name(const struct pt_regs *regs); \ diff --git a/drivers/firmware/efi/runtime-wrappers.c b/drivers/firmware/efi/runtime-wrappers.c index 1410beaef5c3..14e380ac65d4 100644 --- a/drivers/firmware/efi/runtime-wrappers.c +++ b/drivers/firmware/efi/runtime-wrappers.c @@ -162,7 +162,7 @@ static DEFINE_SEMAPHORE(efi_runtime_lock); * Expose the EFI runtime lock to the UV platform */ #ifdef CONFIG_X86_UV -extern struct semaphore __efi_uv_runtime_lock __alias(efi_runtime_lock); +extern struct semaphore __efi_uv_runtime_lock __alias("efi_runtime_lock"); #endif /* diff --git a/include/linux/compiler_attributes.h b/include/linux/compiler_attributes.h index ea7b756b1c8f..4819512c9abd 100644 --- a/include/linux/compiler_attributes.h +++ b/include/linux/compiler_attributes.h @@ -42,7 +42,7 @@ /* * gcc: https://gcc.gnu.org/onlinedocs/gcc/Common-Function-Attributes.html#index-alias-function-attribute */ -#define __alias(symbol) __attribute__((__alias__(#symbol))) +#define __alias(symbol) __attribute__((__alias__(symbol))) /* * gcc: https://gcc.gnu.org/onlinedocs/gcc/Common-Function-Attributes.html#index-aligned-function-attribute diff --git a/kernel/kcsan/core.c b/kernel/kcsan/core.c index 3994a217bde7..465f6cfc317c 100644 --- a/kernel/kcsan/core.c +++ b/kernel/kcsan/core.c @@ -814,7 +814,7 @@ EXPORT_SYMBOL(__kcsan_check_access); } \ EXPORT_SYMBOL(__tsan_read##size); \ void __tsan_unaligned_read##size(void *ptr) \ - __alias(__tsan_read##size); \ + __alias("__tsan_read" #size); \ EXPORT_SYMBOL(__tsan_unaligned_read##size); \ void __tsan_write##size(void *ptr); \ void __tsan_write##size(void *ptr) \ @@ -823,7 +823,7 @@ EXPORT_SYMBOL(__kcsan_check_access); } \ EXPORT_SYMBOL(__tsan_write##size); \ void __tsan_unaligned_write##size(void *ptr) \ - __alias(__tsan_write##size); \ + __alias("__tsan_write" #size); \ EXPORT_SYMBOL(__tsan_unaligned_write##size); \ void __tsan_read_write##size(void *ptr); \ void __tsan_read_write##size(void *ptr) \ @@ -833,7 +833,7 @@ EXPORT_SYMBOL(__kcsan_check_access); } \ EXPORT_SYMBOL(__tsan_read_write##size); \ void __tsan_unaligned_read_write##size(void *ptr) \ - __alias(__tsan_read_write##size); \ + __alias("__tsan_read_write" #size); \ EXPORT_SYMBOL(__tsan_unaligned_read_write##size) DEFINE_TSAN_READ_WRITE(1); @@ -877,7 +877,7 @@ EXPORT_SYMBOL(__tsan_write_range); } \ EXPORT_SYMBOL(__tsan_volatile_read##size); \ void __tsan_unaligned_volatile_read##size(void *ptr) \ - __alias(__tsan_volatile_read##size); \ + __alias("__tsan_volatile_read" #size); \ EXPORT_SYMBOL(__tsan_unaligned_volatile_read##size); \ void __tsan_volatile_write##size(void *ptr); \ void __tsan_volatile_write##size(void *ptr) \ @@ -892,7 +892,7 @@ EXPORT_SYMBOL(__tsan_write_range); } \ EXPORT_SYMBOL(__tsan_volatile_write##size); \ void __tsan_unaligned_volatile_write##size(void *ptr) \ - __alias(__tsan_volatile_write##size); \ + __alias("__tsan_volatile_write" #size); \ EXPORT_SYMBOL(__tsan_unaligned_volatile_write##size) DEFINE_TSAN_VOLATILE_READ_WRITE(1); diff --git a/lib/crc32.c b/lib/crc32.c index 2a68dfd3b96c..373a17aaa432 100644 --- a/lib/crc32.c +++ b/lib/crc32.c @@ -206,8 +206,8 @@ u32 __pure __weak __crc32c_le(u32 crc, unsigned char const *p, size_t len) EXPORT_SYMBOL(crc32_le); EXPORT_SYMBOL(__crc32c_le); -u32 __pure crc32_le_base(u32, unsigned char const *, size_t) __alias(crc32_le); -u32 __pure __crc32c_le_base(u32, unsigned char const *, size_t) __alias(__crc32c_le); +u32 __pure crc32_le_base(u32, unsigned char const *, size_t) __alias("crc32_le"); +u32 __pure __crc32c_le_base(u32, unsigned char const *, size_t) __alias("__crc32c_le"); /* * This multiplies the polynomials x and y modulo the given modulus. diff --git a/lib/crypto/aes.c b/lib/crypto/aes.c index 827fe89922ff..5b80514595c2 100644 --- a/lib/crypto/aes.c +++ b/lib/crypto/aes.c @@ -82,8 +82,8 @@ static volatile const u8 __cacheline_aligned aes_inv_sbox[] = { 0xe1, 0x69, 0x14, 0x63, 0x55, 0x21, 0x0c, 0x7d, }; -extern const u8 crypto_aes_sbox[256] __alias(aes_sbox); -extern const u8 crypto_aes_inv_sbox[256] __alias(aes_inv_sbox); +extern const u8 crypto_aes_sbox[256] __alias("aes_sbox"); +extern const u8 crypto_aes_inv_sbox[256] __alias("aes_inv_sbox"); EXPORT_SYMBOL(crypto_aes_sbox); EXPORT_SYMBOL(crypto_aes_inv_sbox); diff --git a/mm/kasan/generic.c b/mm/kasan/generic.c index 248264b9cb76..4496f897e4f5 100644 --- a/mm/kasan/generic.c +++ b/mm/kasan/generic.c @@ -234,7 +234,7 @@ EXPORT_SYMBOL(__asan_unregister_globals); check_memory_region_inline(addr, size, false, _RET_IP_);\ } \ EXPORT_SYMBOL(__asan_load##size); \ - __alias(__asan_load##size) \ + __alias("__asan_load" #size) \ void __asan_load##size##_noabort(unsigned long); \ EXPORT_SYMBOL(__asan_load##size##_noabort); \ void __asan_store##size(unsigned long addr) \ @@ -242,7 +242,7 @@ EXPORT_SYMBOL(__asan_unregister_globals); check_memory_region_inline(addr, size, true, _RET_IP_); \ } \ EXPORT_SYMBOL(__asan_store##size); \ - __alias(__asan_store##size) \ + __alias("__asan_store" #size) \ void __asan_store##size##_noabort(unsigned long); \ EXPORT_SYMBOL(__asan_store##size##_noabort) @@ -258,7 +258,7 @@ void __asan_loadN(unsigned long addr, size_t size) } EXPORT_SYMBOL(__asan_loadN); -__alias(__asan_loadN) +__alias("__asan_loadN") void __asan_loadN_noabort(unsigned long, size_t); EXPORT_SYMBOL(__asan_loadN_noabort); @@ -268,7 +268,7 @@ void __asan_storeN(unsigned long addr, size_t size) } EXPORT_SYMBOL(__asan_storeN); -__alias(__asan_storeN) +__alias("__asan_storeN") void __asan_storeN_noabort(unsigned long, size_t); EXPORT_SYMBOL(__asan_storeN_noabort);
Like the __section macro, the __alias macro uses macro # stringification to create quotes around the section name used in the __attribute__. Remove the stringification and add quotes or a stringification to the uses instead. Signed-off-by: Joe Perches <joe@perches.com> --- There is a script that might eventually be applied to convert the __section macro definition and uses to remove stringification https://lore.kernel.org/lkml/46f69161e60b802488ba8c8f3f8bbf922aa3b49b.camel@perches.com/ https://lore.kernel.org/lkml/75393e5ddc272dc7403de74d645e6c6e0f4e70eb.camel@perches.com/ This patch is intended to create commonality between the uses of __section and __alias. arch/x86/boot/compressed/string.c | 6 +++--- arch/x86/include/asm/syscall_wrapper.h | 2 +- drivers/firmware/efi/runtime-wrappers.c | 2 +- include/linux/compiler_attributes.h | 2 +- kernel/kcsan/core.c | 10 +++++----- lib/crc32.c | 4 ++-- lib/crypto/aes.c | 4 ++-- mm/kasan/generic.c | 8 ++++---- 8 files changed, 19 insertions(+), 19 deletions(-)