From: Mark Seaborn <mrs@mythic-beasts.com>
Date: Wed, 22 Apr 2009 21:38:36 +0000 (+0100)
Subject: Don't use regparm(3) for functions in ld.so called from libdl.so
X-Git-Tag: nacl-dynlink-0.1~8
X-Git-Url: https://repo.or.cz/w/glibc/nacl-glibc.git/commitdiff_plain/93e9ad06cc80b14f5ab8007105867926f040215e

Don't use regparm(3) for functions in ld.so called from libdl.so
because %ecx is clobbered when calling functions through PLT entries.

This fixes dlopen().

There are a couple of functions that are called from assembly code
and so still need to be defined with regparm.
---

diff --git a/config.h.in b/config.h.in
index b5abb10187..38ed751399 100644
--- a/config.h.in
+++ b/config.h.in
@@ -144,7 +144,7 @@
 /* Defined to some form of __attribute__ ((...)) if the compiler supports
    a different, more efficient calling convention.  */
 #if defined USE_REGPARMS && !defined PROF && !defined __BOUNDED_POINTERS__
-# define internal_function __attribute__ ((regparm (3), stdcall))
+/* # define internal_function __attribute__ ((regparm (3), stdcall)) */
 #endif
 
 /* Linux specific: minimum supported kernel version.  */
diff --git a/elf/dl-init.c b/elf/dl-init.c
index e7b67570fd..d70ee88fb3 100644
--- a/elf/dl-init.c
+++ b/elf/dl-init.c
@@ -89,6 +89,7 @@ call_init (struct link_map *l, int argc, char **argv, char **env)
 
 void
 internal_function
+__attribute__ ((regparm (3), stdcall))
 _dl_init (struct link_map *main_map, int argc, char **argv, char **env)
 {
   ElfW(Dyn) *preinit_array = main_map->l_info[DT_PREINIT_ARRAY];
diff --git a/elf/rtld.c b/elf/rtld.c
index 46bece7fa3..cb70ee4374 100644
--- a/elf/rtld.c
+++ b/elf/rtld.c
@@ -353,6 +353,7 @@ _dl_start_final (void *arg, struct dl_start_final_info *info)
 }
 
 static ElfW(Addr) __attribute_used__ internal_function
+__attribute__ ((regparm (3), stdcall))
 _dl_start (void *arg)
 {
 #ifdef DONT_USE_BOOTSTRAP_MAP
diff --git a/sysdeps/generic/ldsodefs.h b/sysdeps/generic/ldsodefs.h
index 4d857404a3..528d6e89de 100644
--- a/sysdeps/generic/ldsodefs.h
+++ b/sysdeps/generic/ldsodefs.h
@@ -916,7 +916,8 @@ extern int _dl_check_map_versions (struct link_map *map, int verbose,
 /* Initialize the object in SCOPE by calling the constructors with
    ARGC, ARGV, and ENV as the parameters.  */
 extern void _dl_init (struct link_map *main_map, int argc, char **argv,
-		      char **env) internal_function attribute_hidden;
+		      char **env) internal_function attribute_hidden
+                      __attribute__ ((regparm (3), stdcall));
 
 /* Call the finalizer functions of all shared objects whose
    initializer functions have completed.  */