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

[David CARLIER via llvm-commits]

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

>From 65131bfcc1f5d4ab6e356e316ba291ad4abf66d5 Mon Sep 17 00:00:00 2001
From: David Carlier <devnexen at gmail.com>
Date: Wed, 5 Feb 2025 07:40:34 +0000
Subject: [PATCH] [compiler-rt][sanitizer_common] copy_file_range syscall
 interception.

---
 .../sanitizer_common_syscalls.inc             | 22 ++++++++++
 .../TestCases/Linux/copy_file_range.c         | 41 +++++++++++++++++++
 2 files changed, 63 insertions(+)
 create mode 100644 compiler-rt/test/sanitizer_common/TestCases/Linux/copy_file_range.c

diff --git a/compiler-rt/lib/sanitizer_common/sanitizer_common_syscalls.inc b/compiler-rt/lib/sanitizer_common/sanitizer_common_syscalls.inc
index 29fe4721ba40dc9..521fc116f288869 100644
--- a/compiler-rt/lib/sanitizer_common/sanitizer_common_syscalls.inc
+++ b/compiler-rt/lib/sanitizer_common/sanitizer_common_syscalls.inc
@@ -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
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 000000000000000..3fa309022e0c8bd
--- /dev/null
+++ b/compiler-rt/test/sanitizer_common/TestCases/Linux/copy_file_range.c
@@ -0,0 +1,41 @@
+// 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;
+}