From add6e71e4ca7a280b51e7e0e29784f5382e449a0 Mon Sep 17 00:00:00 2001 From: Marijn Suijten Date: Wed, 3 Nov 2021 17:40:19 +0100 Subject: [PATCH] pulsecore/shm: Remove shm_marker struct packing for pa_atomic_t fields Taking addresses of fields in a packed struct are not guaranteed to be aligned, resulting in warnings such as: ../src/pulsecore/shm.c: In function 'sharedmem_create': ../src/pulsecore/shm.c:198:25: error: taking address of packed member of 'struct shm_marker' may result in an unaligned pointer value [-Werror=address-of-packed-member] 198 | pa_atomic_store(&marker->pid, (int) getpid()); | ^~~~~~~~~~~~ The struct already has its fields and types laid out in such a way that the desired packing (without padding) is guaranteed - enforce this with a `static_assert` to get rid of the unaligned pointer warning. Part-of: --- src/pulsecore/shm.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/src/pulsecore/shm.c b/src/pulsecore/shm.c index 0742cb88c..e464f6bce 100644 --- a/src/pulsecore/shm.c +++ b/src/pulsecore/shm.c @@ -91,7 +91,10 @@ struct shm_marker { uint64_t _reserved2; uint64_t _reserved3; uint64_t _reserved4; -} PA_GCC_PACKED; +}; + +// Ensure struct is appropriately packed +static_assert(sizeof(struct shm_marker) == 8 * 5, "`struct shm_marker` is not tightly packed"); static inline size_t shm_marker_size(pa_mem_type_t type) { if (type == PA_MEM_TYPE_SHARED_POSIX)