From: Ammar Faizi <ammarfaizi2@xxxxxxxxxxx> This is a preparation patch to add aarch64 nolibc support. aarch64 supports three values of page size: 4K, 16K, and 64K which are selected at kernel compilation time. Therefore, we can't hard code the page size for this arch. Utilize open(), read() and close() syscall to find the page size from /proc/self/auxv. For more details about the auxv data structure, check the link below. Link: https://github.com/torvalds/linux/blob/v5.19-rc4/fs/binfmt_elf.c#L260 Signed-off-by: Ammar Faizi <ammarfaizi2@xxxxxxxxxxx> --- src/arch/arm64/lib.h | 44 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 44 insertions(+) create mode 100644 src/arch/arm64/lib.h diff --git a/src/arch/arm64/lib.h b/src/arch/arm64/lib.h new file mode 100644 index 0000000..4dc39a8 --- /dev/null +++ b/src/arch/arm64/lib.h @@ -0,0 +1,44 @@ +/* SPDX-License-Identifier: MIT */ + +#ifndef LIBURING_ARCH_ARM64_LIB_H +#define LIBURING_ARCH_ARM64_LIB_H + +#include <elf.h> +#include <sys/auxv.h> +#include "../../syscall.h" + +static inline long get_page_size(void) +{ + Elf64_Off buf[2]; + long page_size; + int fd; + + fd = __sys_open("/proc/self/auxv", O_RDONLY, 0); + if (fd < 0) + return fd; + + while (1) { + ssize_t ret; + + ret = __sys_read(fd, buf, sizeof(buf)); + if (ret < 0) { + page_size = -errno; + break; + } + + if (ret < sizeof(buf)) { + page_size = -ENOENT; + break; + } + + if (buf[0] == AT_PAGESZ) { + page_size = buf[1]; + break; + } + } + + __sys_close(fd); + return page_size; +} + +#endif /* #ifndef LIBURING_ARCH_ARM64_LIB_H */ -- Ammar Faizi
