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

[via llvm-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-compiler-rt-sanitizer

Author: David CARLIER (devnexen)

<details>
<summary>Changes</summary>



---
Full diff: https://github.com/llvm/llvm-project/pull/125816.diff


2 Files Affected:

- (modified) compiler-rt/lib/sanitizer_common/sanitizer_common_syscalls.inc (+20) 
- (added) compiler-rt/test/sanitizer_common/TestCases/Linux/copy_file_range.c (+40) 


``````````diff
diff --git a/compiler-rt/lib/sanitizer_common/sanitizer_common_syscalls.inc b/compiler-rt/lib/sanitizer_common/sanitizer_common_syscalls.inc
index 29fe4721ba40dc..b68b3c2ba86fea 100644
--- a/compiler-rt/lib/sanitizer_common/sanitizer_common_syscalls.inc
+++ b/compiler-rt/lib/sanitizer_common/sanitizer_common_syscalls.inc
@@ -3205,6 +3205,26 @@ 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
diff --git a/compiler-rt/test/sanitizer_common/TestCases/Linux/copy_file_range.c b/compiler-rt/test/sanitizer_common/TestCases/Linux/copy_file_range.c
new file mode 100644
index 00000000000000..a53e6773cf2892
--- /dev/null
+++ b/compiler-rt/test/sanitizer_common/TestCases/Linux/copy_file_range.c
@@ -0,0 +1,40 @@
+// 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 <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;
+}

``````````

</details>


https://github.com/llvm/llvm-project/pull/125816