Skip to content

[compiler-rt][sanitizer_common] copy_file_range syscall interception. #125816

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
merged 1 commit into from
Feb 27, 2025
Merged
Show file tree
Hide file tree
Changes from all commits
Commits
File filter

Filter by extension

Filter by extension

Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
22 changes: 22 additions & 0 deletions compiler-rt/lib/sanitizer_common/sanitizer_common_syscalls.inc
Original file line number Diff line number Diff line change
Expand Up @@ -3205,6 +3205,28 @@ POST_SYSCALL(futex)
COMMON_SYSCALL_BLOCKING_END();
}

PRE_SYSCALL(copy_file_range)
(int fdin, __sanitizer___kernel_off_t *offin, int fdout,
__sanitizer___kernel_off_t *offout, SIZE_T size, unsigned int flags) {
if (offin != nullptr) {
PRE_READ(offin, sizeof(*offin));
}
if (offout != nullptr) {
PRE_READ(offout, sizeof(*offout));
}
}

POST_SYSCALL(copy_file_range)
(SSIZE_T, int fdin, __sanitizer___kernel_off_t *offin, int fdout,
__sanitizer___kernel_off_t *offout, SIZE_T size, unsigned int flags) {
if (offin != nullptr) {
POST_WRITE(offin, sizeof(*offin));
}
if (offout != nullptr) {
POST_WRITE(offout, sizeof(*offout));
}
}

} // extern "C"

# undef PRE_SYSCALL
Expand Down
Original file line number Diff line number Diff line change
@@ -0,0 +1,42 @@
// RUN: %clangxx -O0 %s -o %t

// REQUIRES: glibc

#ifndef _GNU_SOURCE
# define _GNU_SOURCE
#endif
#include <assert.h>
#include <fcntl.h>
#include <stdlib.h>
#include <sys/syscall.h>
#include <unistd.h>

#if !defined(__GLIBC_PREREQ)
# define __GLIBC_PREREQ(a, b) 0
#endif

#if !__GLIBC_PREREQ(2, 27)
# define copy_file_range(a, b, c, d, e) \
(ssize_t) syscall(__NR_copy_file_range, a, b, c, d, e)
#endif

int main(void) {
int fdin = open("/proc/self/maps", O_RDONLY);
assert(fdin > 0);
char tmp[] = "/tmp/map.XXXXXX";
int fdout = mkstemp(tmp);
assert(fdout > 0);
off_t offin = -1, offout = 0;
ssize_t cpy = copy_file_range(fdin, &offin, fdout, &offout, 8, 0);
assert(cpy < 0);
offin = 0;
offout = 16;
cpy = copy_file_range(fdin, &offin, fdout, &offout, 8, 0);
assert(cpy < 0);
offout = 0;
cpy = copy_file_range(fdin, &offin, fdout, &offout, 8, 0);
assert(cpy == 8);
close(fdout);
close(fdin);
return 0;
}