user/sven/linux.git/include/vdso, branch v6.16.2

vdso: Address variable shadowing in macros

2025-04-10T09:07:10Z

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 Signed-off-by: Shao Mingyin Signed-off-by: Thomas Gleixner Link: https://lore.kernel.org/all/20250324191230477zpGtgIRSH4mEHdtxGtgx9@zte.com.cn

vdso: Rework struct vdso_time_data and introduce struct vdso_clock

2025-03-08T13:37:41Z

To support multiple PTP clocks, the VDSO data structure needs to be reworked. All clock specific data will end up in struct vdso_clock and in struct vdso_time_data there will be an array of VDSO clocks. Now that all preparatory changes are in place: Split the clock related struct members into a separate struct vdso_clock. Make sure all users are aware, that vdso_time_data is no longer initialized as an array and vdso_clock is now the array inside vdso_data. Remove the vdso_clock define, which mapped it to vdso_time_data for the transition. Signed-off-by: Anna-Maria Behnsen Signed-off-by: Nam Cao Signed-off-by: Thomas Weißschuh Signed-off-by: Thomas Gleixner Link: https://lore.kernel.org/all/20250303-vdso-clock-v1-19-c1b5c69a166f@linutronix.de

vdso: Move architecture related data before basetime data

2025-03-08T13:37:41Z

Architecture related vdso data is required in the fast path when reading CLOCK_MONOTONIC or CLOCK_REALTIME. At the moment, this information is located at the end of the vdso_time_data structure, which is a suboptimal cache layout. Move the architecture specific VDSO data right before the basetime information, which is always required. This change does not have an impact on architectures with CONFIG_ARCH_HAS_VDSO_DATA=n. Architectures, which have it enabled, gain a better cache layout. Signed-off-by: Anna-Maria Behnsen Signed-off-by: Nam Cao Signed-off-by: Thomas Weißschuh Signed-off-by: Thomas Gleixner Link: https://lore.kernel.org/all/20250303-vdso-clock-v1-18-c1b5c69a166f@linutronix.de

vdso/helpers: Prepare introduction of struct vdso_clock

2025-03-08T13:37:40Z

To support multiple PTP clocks, the VDSO data structure needs to be reworked. All clock specific data will end up in struct vdso_clock and in struct vdso_time_data there will be an array of VDSO clocks. For now, vdso_clock is simply a define which maps vdso_clock to vdso_time_data. Prepare all functions which need the pointer to the vdso_clock array to work well after the structures get reworked. Replace the struct vdso_time_data pointer with a struct vdso_clock pointer where applicable. No functional change. Signed-off-by: Anna-Maria Behnsen Signed-off-by: Nam Cao Signed-off-by: Thomas Weißschuh Signed-off-by: Thomas Gleixner Link: https://lore.kernel.org/all/20250303-vdso-clock-v1-5-c1b5c69a166f@linutronix.de

vdso/datapage: Define vdso_clock to prepare for multiple PTP clocks

2025-03-08T13:37:40Z

Multiple PTP clocks, which are independent of timekeeping, are required for systems, which utilize PTP for synchronizing e.g. automation systems independent of clock TAI. PTP clocks are slow to access, but applications require fast access to the relevant time similar to the regular timekeeping relevant clocks. To prepare for that the VDSO data representation must be reworked. For transition to the new structure of the vdso, add a define which maps vdso_clock to vdso_data. This will be removed when all users are updated step by step. No functional change. Signed-off-by: Anna-Maria Behnsen Signed-off-by: Nam Cao Signed-off-by: Thomas Weißschuh Signed-off-by: Thomas Gleixner Link: https://lore.kernel.org/all/20250303-vdso-clock-v1-4-c1b5c69a166f@linutronix.de

vdso: Make vdso_time_data cacheline aligned

2025-03-08T13:37:39Z

vdso_time_data is not cacheline aligned at the moment. When instantiating an array, the start of the second array member is not cache line aligned. This increases the number of the required cache lines which needs to be read when handling e.g. CLOCK_MONOTONIC_RAW, because the data spawns an extra cache line if the previous data does not end at a cache line boundary. Therefore make struct vdso_time_data cacheline aligned. Signed-off-by: Anna-Maria Behnsen Signed-off-by: Nam Cao Signed-off-by: Thomas Weißschuh Signed-off-by: Thomas Gleixner Link: https://lore.kernel.org/all/20250303-vdso-clock-v1-3-c1b5c69a166f@linutronix.de

vdso: Introduce vdso/cache.h

2025-03-08T13:37:39Z

The vDSO implementation can only include headers from the vdso/ namespace. To enable the usage of ____cacheline_aligned from the vDSO, move it and its dependencies into a new header vdso/cache.h. Keep compatibility by including vdso/cache.h from linux/cache.h. Signed-off-by: Thomas Weißschuh Signed-off-by: Thomas Gleixner Link: https://lore.kernel.org/all/20250303-vdso-clock-v1-1-c1b5c69a166f@linutronix.de

vdso: Remove remnants of architecture-specific time storage

2025-02-21T08:54:03Z

All users of the time releated parts of the vDSO are now using the generic storage implementation. Remove the therefore unnecessary compatibility accessor functions and symbols. Co-developed-by: Nam Cao Signed-off-by: Nam Cao Signed-off-by: Thomas Weißschuh Signed-off-by: Thomas Gleixner Link: https://lore.kernel.org/all/20250204-vdso-store-rng-v3-18-13a4669dfc8c@linutronix.de

vdso: Remove remnants of architecture-specific random state storage

2025-02-21T08:54:03Z

All users of the random vDSO are using the generic storage implementation. Remove the now unnecessary compatibility accessor functions and symbols. Co-developed-by: Nam Cao Signed-off-by: Nam Cao Signed-off-by: Thomas Weißschuh Signed-off-by: Thomas Gleixner Link: https://lore.kernel.org/all/20250204-vdso-store-rng-v3-17-13a4669dfc8c@linutronix.de

vdso: Add generic architecture-specific data storage

2025-02-21T08:54:01Z

Some architectures need to expose architecture-specific data to the vDSO. Enable the generic vDSO storage mechanism to both store and map this data. Some architectures require more than a single page, like LoongArch, so prepare for that usecase, too. Signed-off-by: Thomas Weißschuh Signed-off-by: Thomas Gleixner Link: https://lore.kernel.org/all/20250204-vdso-store-rng-v3-7-13a4669dfc8c@linutronix.de