linux/include/vdso/unaligned.h

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef __VDSO_UNALIGNED_H
#define __VDSO_UNALIGNED_H

#define __get_unaligned_t(type, ptr) ({							\
	const struct { type x; } __packed * __get_pptr = (typeof(__get_pptr))(ptr);	\
	__get_pptr->x;									\
})

#define __put_unaligned_t(type, val, ptr) do {						\
	struct { type x; } __packed * __put_pptr = (typeof(__put_pptr))(ptr);		\
	__put_pptr->x = (val);								\
} while (0)

#endif /* __VDSO_UNALIGNED_H */
random: vDSO: minimize and simplify header includes Depending on the architecture, building a 32-bit vDSO on a 64-bit kernel is problematic when some system headers are included. Minimise the amount of headers by moving needed items, such as __{get,put}_unaligned_t, into dedicated common headers and in general use more specific headers, similar to what was done in commit 8165b57bca21 ("linux/const.h: Extract common header for vDSO") and commit 8c59ab839f52 ("lib/vdso: Enable common headers"). On some architectures this results in missing PAGE_SIZE, as was described by commit 8b3843ae3634 ("vdso/datapage: Quick fix - use asm/page-def.h for ARM64"), so define this if necessary, in the same way as done prior by commit cffaefd15a8f ("vdso: Use CONFIG_PAGE_SHIFT in vdso/datapage.h"). Removing linux/time64.h leads to missing 'struct timespec64' in x86's asm/pvclock.h. Add a forward declaration of that struct in that file. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> 2024-08-27 09:31:47 +02:00			`/* SPDX-License-Identifier: GPL-2.0 */`
			`#ifndef __VDSO_UNALIGNED_H`
			`#define __VDSO_UNALIGNED_H`

vdso: Address variable shadowing in macros Compiling the kernel with gcc12.3 W=2 results in shadowing warnings: warning: declaration of '__pptr' shadows a previous local [-Wshadow] const struct { type x; } __packed *__pptr = (typeof(__pptr))(ptr); note: in definition of macro '__put_unaligned_t' __pptr->x = (val); note: in expansion of macro '__get_unaligned_t' __put_unaligned_t(type, __get_unaligned_t(type, src), dst); __get_unaligned_t() and __put_unaligned_t() use a local variable named '__pptr', which can lead to variable shadowing when these macros are used in the same scope. This results in a -Wshadow warning during compilation. To address this issue, rename the local variables within the macros to ensure uniqueness. Signed-off-by: Peng Jiang <jiang.peng9@zte.com.cn> Signed-off-by: Shao Mingyin <shao.mingyin@zte.com.cn> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/all/20250324191230477zpGtgIRSH4mEHdtxGtgx9@zte.com.cn 2025-03-24 19:12:30 +08:00			`#define __get_unaligned_t(type, ptr) ({ \`
			`const struct { type x; } __packed * __get_pptr = (typeof(__get_pptr))(ptr); \`
			`__get_pptr->x; \`
random: vDSO: minimize and simplify header includes Depending on the architecture, building a 32-bit vDSO on a 64-bit kernel is problematic when some system headers are included. Minimise the amount of headers by moving needed items, such as __{get,put}_unaligned_t, into dedicated common headers and in general use more specific headers, similar to what was done in commit 8165b57bca21 ("linux/const.h: Extract common header for vDSO") and commit 8c59ab839f52 ("lib/vdso: Enable common headers"). On some architectures this results in missing PAGE_SIZE, as was described by commit 8b3843ae3634 ("vdso/datapage: Quick fix - use asm/page-def.h for ARM64"), so define this if necessary, in the same way as done prior by commit cffaefd15a8f ("vdso: Use CONFIG_PAGE_SHIFT in vdso/datapage.h"). Removing linux/time64.h leads to missing 'struct timespec64' in x86's asm/pvclock.h. Add a forward declaration of that struct in that file. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> 2024-08-27 09:31:47 +02:00			`})`

vdso: Address variable shadowing in macros Compiling the kernel with gcc12.3 W=2 results in shadowing warnings: warning: declaration of '__pptr' shadows a previous local [-Wshadow] const struct { type x; } __packed *__pptr = (typeof(__pptr))(ptr); note: in definition of macro '__put_unaligned_t' __pptr->x = (val); note: in expansion of macro '__get_unaligned_t' __put_unaligned_t(type, __get_unaligned_t(type, src), dst); __get_unaligned_t() and __put_unaligned_t() use a local variable named '__pptr', which can lead to variable shadowing when these macros are used in the same scope. This results in a -Wshadow warning during compilation. To address this issue, rename the local variables within the macros to ensure uniqueness. Signed-off-by: Peng Jiang <jiang.peng9@zte.com.cn> Signed-off-by: Shao Mingyin <shao.mingyin@zte.com.cn> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/all/20250324191230477zpGtgIRSH4mEHdtxGtgx9@zte.com.cn 2025-03-24 19:12:30 +08:00			`#define __put_unaligned_t(type, val, ptr) do { \`
			`struct { type x; } __packed * __put_pptr = (typeof(__put_pptr))(ptr); \`
			`__put_pptr->x = (val); \`
random: vDSO: minimize and simplify header includes Depending on the architecture, building a 32-bit vDSO on a 64-bit kernel is problematic when some system headers are included. Minimise the amount of headers by moving needed items, such as __{get,put}_unaligned_t, into dedicated common headers and in general use more specific headers, similar to what was done in commit 8165b57bca21 ("linux/const.h: Extract common header for vDSO") and commit 8c59ab839f52 ("lib/vdso: Enable common headers"). On some architectures this results in missing PAGE_SIZE, as was described by commit 8b3843ae3634 ("vdso/datapage: Quick fix - use asm/page-def.h for ARM64"), so define this if necessary, in the same way as done prior by commit cffaefd15a8f ("vdso: Use CONFIG_PAGE_SHIFT in vdso/datapage.h"). Removing linux/time64.h leads to missing 'struct timespec64' in x86's asm/pvclock.h. Add a forward declaration of that struct in that file. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> 2024-08-27 09:31:47 +02:00			`} while (0)`

			`#endif /* __VDSO_UNALIGNED_H */`