<chromium> Do not directly override libc symbols from the library.

Instead we export _override symbols and add the symbol
renaming directly into the QtWebEngineProcess source.

Reviewed-by: Andras Becsi <[email protected]>
Change-Id: I15049609dd77be6de2a2398f25a37fff1b6f5519
Reviewed-by: Zeno Albisser <[email protected]>

Author: zenoalbisser

chromium/content/zygote/zygote_main_linux.cc

@@ -181,8 +181,6 @@ static void InitLibcLocaltimeFunctions() {
 // references to localtime() will resolve to this function. Notice that we need
 // to set visibility attribute to "default" to export the symbol, as it is set
 // to "hidden" by default in chrome per build/common.gypi.
-__attribute__ ((__visibility__("default")))
-struct tm* localtime_override(const time_t* timep) __asm__ ("localtime");
 
 __attribute__ ((__visibility__("default")))
 struct tm* localtime_override(const time_t* timep) {
@@ -199,10 +197,6 @@ struct tm* localtime_override(const time_t* timep) {
   }
 }
 
-// Use same trick to override localtime64(), localtime_r() and localtime64_r().
-__attribute__ ((__visibility__("default")))
-struct tm* localtime64_override(const time_t* timep) __asm__ ("localtime64");
-
 __attribute__ ((__visibility__("default")))
 struct tm* localtime64_override(const time_t* timep) {
   if (g_am_zygote_or_renderer) {
@@ -218,10 +212,6 @@ struct tm* localtime64_override(const time_t* timep) {
   }
 }
 
-__attribute__ ((__visibility__("default")))
-struct tm* localtime_r_override(const time_t* timep,
-                                struct tm* result) __asm__ ("localtime_r");
-
 __attribute__ ((__visibility__("default")))
 struct tm* localtime_r_override(const time_t* timep, struct tm* result) {
   if (g_am_zygote_or_renderer) {
@@ -234,10 +224,6 @@ struct tm* localtime_r_override(const time_t* timep, struct tm* result) {
   }
 }
 
-__attribute__ ((__visibility__("default")))
-struct tm* localtime64_r_override(const time_t* timep,
-                                  struct tm* result) __asm__ ("localtime64_r");
-
 __attribute__ ((__visibility__("default")))
 struct tm* localtime64_r_override(const time_t* timep, struct tm* result) {
   if (g_am_zygote_or_renderer) {

chromium/sandbox/linux/services/libc_urandom_override.cc

@@ -121,8 +121,6 @@ static void InitLibcFileIOFunctions() {
 // the code below defines fopen_override() function with asm name
 // "fopen", so that all references to fopen() will resolve to this
 // function.
-__attribute__ ((__visibility__("default")))
-FILE* fopen_override(const char* path, const char* mode)  __asm__ ("fopen");
 
 __attribute__ ((__visibility__("default")))
 FILE* fopen_override(const char* path, const char* mode) {
@@ -141,7 +139,7 @@ FILE* fopen_override(const char* path, const char* mode) {
 }
 
 __attribute__ ((__visibility__("default")))
-FILE* fopen64(const char* path, const char* mode) {
+FILE* fopen64_override(const char* path, const char* mode) {
   if (g_override_urandom && strcmp(path, kUrandomDevPath) == 0) {
     int fd = HANDLE_EINTR(dup(base::GetUrandomFD()));
     if (fd < 0) {
@@ -161,11 +159,6 @@ FILE* fopen64(const char* path, const char* mode) {
 
 #if HAVE_XSTAT
 
-__attribute__ ((__visibility__("default")))
-int xstat_override(int version,
-                   const char *path,
-                   struct stat *buf)  __asm__ ("__xstat");
-
 __attribute__ ((__visibility__("default")))
 int xstat_override(int version, const char *path, struct stat *buf) {
   if (g_override_urandom && strcmp(path, kUrandomDevPath) == 0) {
@@ -178,11 +171,6 @@ int xstat_override(int version, const char *path, struct stat *buf) {
   }
 }
 
-__attribute__ ((__visibility__("default")))
-int xstat64_override(int version,
-                     const char *path,
-                     struct stat64 *buf)  __asm__ ("__xstat64");
-
 __attribute__ ((__visibility__("default")))
 int xstat64_override(int version, const char *path, struct stat64 *buf) {
   if (g_override_urandom && strcmp(path, kUrandomDevPath) == 0) {
@@ -197,10 +185,6 @@ int xstat64_override(int version, const char *path, struct stat64 *buf) {
 
 #else
 
-__attribute__ ((__visibility__("default")))
-int stat_override(const char *path,
-                  struct stat *buf)  __asm__ ("stat");
-
 __attribute__ ((__visibility__("default")))
 int stat_override(const char *path, struct stat *buf) {
   if (g_override_urandom && strcmp(path, kUrandomDevPath) == 0) {
@@ -213,10 +197,6 @@ int stat_override(const char *path, struct stat *buf) {
   }
 }
 
-__attribute__ ((__visibility__("default")))
-int stat64_override(const char *path,
-                    struct stat64 *buf)  __asm__ ("stat64");
-
 __attribute__ ((__visibility__("default")))
 int stat64_override(const char *path, struct stat64 *buf) {
   if (g_override_urandom && strcmp(path, kUrandomDevPath) == 0) {