platform_bionic/libc/arch-arm/syscalls/___fsetxattr.S
Nick Kralevich 2825f10b7f libc: Add O_PATH support for fgetxattr / fsetxattr
Support O_PATH file descriptors when handling fgetxattr and fsetxattr.
This avoids requiring file read access to pull extended attributes.

This is needed to support O_PATH file descriptors when calling
SELinux's fgetfilecon() call. In particular, this allows the querying
and setting of SELinux file context by using something like the following
code:

  int dirfd = open("/path/to/dir", O_DIRECTORY);
  int fd = openat(dirfd, "file", O_PATH | O_NOFOLLOW);
  char *context;
  fgetfilecon(fd, &context);

This change was motivated by a comment in
https://android-review.googlesource.com/#/c/152680/1/toys/posix/ls.c

Change-Id: Ic0cdf9f9dd0e35a63b44a4c4a08400020041eddf
2015-06-01 15:51:56 -07:00

23 lines
562 B
ArmAsm

/* Generated by gensyscalls.py. Do not edit. */
#include <private/bionic_asm.h>
ENTRY(___fsetxattr)
mov ip, sp
stmfd sp!, {r4, r5, r6, r7}
.cfi_def_cfa_offset 16
.cfi_rel_offset r4, 0
.cfi_rel_offset r5, 4
.cfi_rel_offset r6, 8
.cfi_rel_offset r7, 12
ldmfd ip, {r4, r5, r6}
ldr r7, =__NR_fsetxattr
swi #0
ldmfd sp!, {r4, r5, r6, r7}
.cfi_def_cfa_offset 0
cmn r0, #(MAX_ERRNO + 1)
bxls lr
neg r0, r0
b __set_errno_internal
END(___fsetxattr)
.hidden ___fsetxattr