diff options
| author | Daniel Palmer <daniel@thingy.jp> | 2026-08-28 19:32:04 +0900 |
|---|---|---|
| committer | Thomas Weißschuh <linux@weissschuh.net> | 2026-08-31 06:19:24 +0200 |
| commit | c0da8b53603ad84f622b2c5f6c1a69f7d4b4b8bc (patch) | |
| tree | 29284760fe7ed616aba20b9317f5272ef5a92a69 /tools/include | |
| parent | 4c00540add56942d621a941481cf9d0fb7dcec0e (diff) | |
| download | linux-next-c0da8b53603ad84f622b2c5f6c1a69f7d4b4b8bc.tar.gz linux-next-c0da8b53603ad84f622b2c5f6c1a69f7d4b4b8bc.zip | |
tools/nolibc: Add sendfile()
This is useful because it allows copying data up to 2GB from one
fd to another without a buffer in userspace and with a single syscall.
For 32bit kernels we use the sendfile64 syscall to allow for 64bit
offsets to work.
Signed-off-by: Daniel Palmer <daniel@thingy.jp>
Link: https://patch.msgid.link/20260828103205.384589-2-daniel@thingy.jp
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Diffstat (limited to 'tools/include')
| -rw-r--r-- | tools/include/nolibc/Makefile | 1 | ||||
| -rw-r--r-- | tools/include/nolibc/nolibc.h | 1 | ||||
| -rw-r--r-- | tools/include/nolibc/sys/sendfile.h | 41 |
3 files changed, 43 insertions, 0 deletions
diff --git a/tools/include/nolibc/Makefile b/tools/include/nolibc/Makefile index c4a0879e4140..0880be0f6ef5 100644 --- a/tools/include/nolibc/Makefile +++ b/tools/include/nolibc/Makefile @@ -75,6 +75,7 @@ all_files := \ sys/reboot.h \ sys/resource.h \ sys/select.h \ + sys/sendfile.h \ sys/stat.h \ sys/syscall.h \ sys/sysmacros.h \ diff --git a/tools/include/nolibc/nolibc.h b/tools/include/nolibc/nolibc.h index faa94f247281..352a207bbedc 100644 --- a/tools/include/nolibc/nolibc.h +++ b/tools/include/nolibc/nolibc.h @@ -106,6 +106,7 @@ #include "sys/reboot.h" #include "sys/resource.h" #include "sys/select.h" +#include "sys/sendfile.h" #include "sys/stat.h" #include "sys/syscall.h" #include "sys/sysmacros.h" diff --git a/tools/include/nolibc/sys/sendfile.h b/tools/include/nolibc/sys/sendfile.h new file mode 100644 index 000000000000..ac7d85847718 --- /dev/null +++ b/tools/include/nolibc/sys/sendfile.h @@ -0,0 +1,41 @@ +/* SPDX-License-Identifier: LGPL-2.1 OR MIT */ +/* + * sendfile for NOLIBC + * Copyright (C) 2026 Daniel Palmer <daniel@thingy.jp> + */ + +/* make sure to include all global symbols */ +#include "../nolibc.h" + +#ifndef _NOLIBC_SYS_SENDFILE_H +#define _NOLIBC_SYS_SENDFILE_H + +#include "../sys.h" +#include <linux/unistd.h> + +/* + * ssize_t sendfile(int out_fd, int in_fd, off_t *offset, size_t count); + */ + +static __attribute__((unused)) +ssize_t _sys_sendfile(int out_fd, int in_fd, off_t *offset, size_t count) +{ + __nolibc_static_assert(sizeof(*offset) == sizeof(__kernel_loff_t)); + +#ifdef __NR_sendfile64 + /* 32-bit applications use sendfile64 so offset is treated as a __kernel_loff_t */ + return __nolibc_syscall4(__NR_sendfile64, out_fd, in_fd, offset, count); +#else + __nolibc_static_assert(sizeof(*offset) == sizeof(__kernel_off_t)); + + return __nolibc_syscall4(__NR_sendfile, out_fd, in_fd, offset, count); +#endif +} + +static __attribute__((unused)) +ssize_t sendfile(int out_fd, int in_fd, off_t *offset, size_t count) +{ + return __sysret(_sys_sendfile(out_fd, in_fd, offset, count)); +} + +#endif /* _NOLIBC_SYS_SENDFILE_H */ |