add fortified implementations of write/pwrite{,64}
These are just based on the read/pread{,64} implementations with the
function calls and error messages adjusted as appropriate. The only
difference is that the buffer parameters are const.
Change-Id: Ida1597a903807f583f230d74bcedffdb7b24fcf6
diff --git a/libc/include/unistd.h b/libc/include/unistd.h
index 904447c..91ae89e 100644
--- a/libc/include/unistd.h
+++ b/libc/include/unistd.h
@@ -238,11 +238,26 @@
__errordecl(__pread64_count_toobig_error, "pread64 called with count > SSIZE_MAX");
extern ssize_t __pread64_real(int, void*, size_t, off64_t) __RENAME(pread64);
+extern ssize_t __pwrite_chk(int, const void*, size_t, off_t, size_t);
+__errordecl(__pwrite_dest_size_error, "pwrite called with size bigger than destination");
+__errordecl(__pwrite_count_toobig_error, "pwrite called with count > SSIZE_MAX");
+extern ssize_t __pwrite_real(int, const void*, size_t, off_t) __RENAME(pwrite);
+
+extern ssize_t __pwrite64_chk(int, const void*, size_t, off64_t, size_t);
+__errordecl(__pwrite64_dest_size_error, "pwrite64 called with size bigger than destination");
+__errordecl(__pwrite64_count_toobig_error, "pwrite64 called with count > SSIZE_MAX");
+extern ssize_t __pwrite64_real(int, const void*, size_t, off64_t) __RENAME(pwrite64);
+
extern ssize_t __read_chk(int, void*, size_t, size_t);
__errordecl(__read_dest_size_error, "read called with size bigger than destination");
__errordecl(__read_count_toobig_error, "read called with count > SSIZE_MAX");
extern ssize_t __read_real(int, void*, size_t) __RENAME(read);
+extern ssize_t __write_chk(int, const void*, size_t, size_t);
+__errordecl(__write_dest_size_error, "write called with size bigger than destination");
+__errordecl(__write_count_toobig_error, "write called with count > SSIZE_MAX");
+extern ssize_t __write_real(int, const void*, size_t) __RENAME(write);
+
extern ssize_t __readlink_chk(const char*, char*, size_t, size_t);
__errordecl(__readlink_dest_size_error, "readlink called with size bigger than destination");
__errordecl(__readlink_size_toobig_error, "readlink called with size > SSIZE_MAX");
@@ -342,6 +357,62 @@
return __pread64_chk(fd, buf, count, offset, bos);
}
+#if defined(__USE_FILE_OFFSET64)
+#define __PWRITE_PREFIX(x) __pwrite64_ ## x
+#else
+#define __PWRITE_PREFIX(x) __pwrite_ ## x
+#endif
+
+__BIONIC_FORTIFY_INLINE
+ssize_t pwrite(int fd, const void* buf, size_t count, off_t offset) {
+ size_t bos = __bos0(buf);
+
+#if !defined(__clang__)
+ if (__builtin_constant_p(count) && (count > SSIZE_MAX)) {
+ __PWRITE_PREFIX(count_toobig_error)();
+ }
+
+ if (bos == __BIONIC_FORTIFY_UNKNOWN_SIZE) {
+ return __PWRITE_PREFIX(real)(fd, buf, count, offset);
+ }
+
+ if (__builtin_constant_p(count) && (count > bos)) {
+ __PWRITE_PREFIX(dest_size_error)();
+ }
+
+ if (__builtin_constant_p(count) && (count <= bos)) {
+ return __PWRITE_PREFIX(real)(fd, buf, count, offset);
+ }
+#endif
+
+ return __PWRITE_PREFIX(chk)(fd, buf, count, offset, bos);
+}
+
+__BIONIC_FORTIFY_INLINE
+ssize_t pwrite64(int fd, const void* buf, size_t count, off64_t offset) {
+ size_t bos = __bos0(buf);
+
+#if !defined(__clang__)
+ if (__builtin_constant_p(count) && (count > SSIZE_MAX)) {
+ __pwrite64_count_toobig_error();
+ }
+
+ if (bos == __BIONIC_FORTIFY_UNKNOWN_SIZE) {
+ return __pwrite64_real(fd, buf, count, offset);
+ }
+
+ if (__builtin_constant_p(count) && (count > bos)) {
+ __pwrite64_dest_size_error();
+ }
+
+ if (__builtin_constant_p(count) && (count <= bos)) {
+ return __pwrite64_real(fd, buf, count, offset);
+ }
+#endif
+
+ return __pwrite64_chk(fd, buf, count, offset, bos);
+}
+
__BIONIC_FORTIFY_INLINE
ssize_t read(int fd, void* buf, size_t count) {
size_t bos = __bos0(buf);
@@ -368,6 +439,33 @@
}
__BIONIC_FORTIFY_INLINE
+ssize_t write(int fd, const void* buf, size_t count) {
+ size_t bos = __bos0(buf);
+
+#if !defined(__clang__)
+#if 0 /* work around a false positive due to a missed optimization */
+ if (__builtin_constant_p(count) && (count > SSIZE_MAX)) {
+ __write_count_toobig_error();
+ }
+#endif
+
+ if (bos == __BIONIC_FORTIFY_UNKNOWN_SIZE) {
+ return __write_real(fd, buf, count);
+ }
+
+ if (__builtin_constant_p(count) && (count > bos)) {
+ __write_dest_size_error();
+ }
+
+ if (__builtin_constant_p(count) && (count <= bos)) {
+ return __write_real(fd, buf, count);
+ }
+#endif
+
+ return __write_chk(fd, buf, count, bos);
+}
+
+__BIONIC_FORTIFY_INLINE
ssize_t readlink(const char* path, char* buf, size_t size) {
size_t bos = __bos(buf);