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Re: PATCH: invalid IFUNC DW_AT_linkage_name: memmove strstr time


On Thu, Aug 9, 2012 at 2:05 PM, Roland McGrath <roland@hack.frob.com> wrote:
>> +/* Redefine strstr so that compiler won't complain the type mismatch
>> +   from strong_alias below.  */
>
> "Redefine strstr so that the compiler won't complain about the type
> mismatch with the IFUNC selector in strong_alias, below."
>
>> +/* Redefine time so that compiler won't complain the type mismatch
>> +   from strong_alias below.  */
>
> Similar fix.
>
>> -void *time_ifunc (void) __asm__ ("time");
>> +/* Avoid DWARF definition DIE on ifunc symbol so that GDB can handle
>> +   ifunc symbol properly.  */
>> +extern time_t __GI_time (time_t *);
>> +void *time_ifunc (void) __asm__ ("__GI_time");
>
> Can you make this __libc_time and let the __GI_* magic name
> come from libc_hidden_def as normal?

I don't think it is possible since we have changed time with

/* Redefine time so that the compiler won't complain about the type
   mismatch with the IFUNC selector in strong_alias, below.  */
#undef time
#define time __redirect_time


>> +/* Redefine memmove so that compiler won't complain the type mismatch
>> +   from strong_alias below.  */
>
> Needs similar grammar fixes as above.
>
>> +/* Redefine strstr so that compiler won't complain the type mismatch
>> +   from strong_alias below.  */
>
> Likewise.
>

Fixed.  OK to install?


-- 
H.J.
---
	[BZ #14166]
	* sysdeps/i386/i686/multiarch/strstr-c.c (strstr): Redefined
	to __redirect_strstr.
	(__strstr_sse42): Use typeof __redirect_strstr.
	(__strstr_ia32): Likewise.
	(__libc_strstr): New prototype.
	(strstr): Renamed to ...
	(__libc_strstr): This.
	(strstr): New strong alias of __libc_strstr.
	* sysdeps/x86_64/multiarch/strstr-c.c: Likewise.
	* sysdeps/unix/sysv/linux/x86_64/time.c (time): Redefined to
	__redirect_time.
	Include <time.h>.
	(__GI_time): New prototype.
	(time_ifunc): Replace time with __GI_time.
	(time): New strong alias of __GI_time.
	(__GI_time): Remove strong alias.
	* sysdeps/x86_64/multiarch/memmove.c: Don't include <string.h>.
	Include <stddef.h>.
	(memmove): Redefined to __redirect_memmove.
	(__memmove_sse2): Use typeof __redirect_memmove.
	(__memmove_ssse3): Likewise.
	(__memmove_ssse3_back): Likewise.
	(__libc_memmove): New prototype.
	(memmove): Renamed to ...
	(__libc_memmove): This.
	(memmove): New strong alias of __libc_memmove.

diff --git a/sysdeps/i386/i686/multiarch/strstr-c.c
b/sysdeps/i386/i686/multiarch/strstr-c.c
index 1fcb00e..17c75c5 100644
--- a/sysdeps/i386/i686/multiarch/strstr-c.c
+++ b/sysdeps/i386/i686/multiarch/strstr-c.c
@@ -7,9 +7,20 @@
   __hidden_ver1 (__strstr_ia32, __GI_strstr, __strstr_ia32);
 #endif

+/* Redefine strstr so that the compiler won't complain about the type
+   mismatch with the IFUNC selector in strong_alias, below.  */
+#undef strstr
+#define strstr __redirect_strstr
+
 #include "string/strstr.c"

-extern char *__strstr_sse42 (const char *, const char *) attribute_hidden;
-extern __typeof (__strstr_ia32) __strstr_ia32 attribute_hidden;
+extern __typeof (__redirect_strstr) __strstr_sse42 attribute_hidden;
+extern __typeof (__redirect_strstr) __strstr_ia32 attribute_hidden;
+
+/* Avoid DWARF definition DIE on ifunc symbol so that GDB can handle
+   ifunc symbol properly.  */
+extern __typeof (__redirect_strstr) __libc_strstr;
+libc_ifunc (__libc_strstr, HAS_SSE4_2 ? __strstr_sse42 : __strstr_ia32)

-libc_ifunc (strstr, HAS_SSE4_2 ? __strstr_sse42 : __strstr_ia32);
+#undef strstr
+strong_alias (__libc_strstr, strstr)
diff --git a/sysdeps/unix/sysv/linux/x86_64/time.c
b/sysdeps/unix/sysv/linux/x86_64/time.c
index 0e05ddd..f79efcb 100644
--- a/sysdeps/unix/sysv/linux/x86_64/time.c
+++ b/sysdeps/unix/sysv/linux/x86_64/time.c
@@ -16,11 +16,20 @@
    <http://www.gnu.org/licenses/>.  */

 #ifdef SHARED
+/* Redefine time so that the compiler won't complain about the type
+   mismatch with the IFUNC selector in strong_alias, below.  */
+#undef time
+#define time __redirect_time
+#include <time.h>
+
 #include <dl-vdso.h>

 #define VSYSCALL_ADDR_vtime	0xffffffffff600400

-void *time_ifunc (void) __asm__ ("time");
+/* Avoid DWARF definition DIE on ifunc symbol so that GDB can handle
+   ifunc symbol properly.  */
+extern __typeof (__redirect_time) __GI_time;
+void *time_ifunc (void) __asm__ ("__GI_time");

 void *
 time_ifunc (void)
@@ -30,7 +39,10 @@ time_ifunc (void)
   /* If the vDSO is not available we fall back on the old vsyscall.  */
   return _dl_vdso_vsym ("__vdso_time", &linux26) ?: (void *)
VSYSCALL_ADDR_vtime;
 }
-__asm (".type time, %gnu_indirect_function");
+__asm (".type __GI_time, %gnu_indirect_function");
+
+#undef time
+strong_alias (__GI_time, time)

 #else

@@ -45,5 +57,3 @@ time (time_t *t)
 }

 #endif
-
-strong_alias (time, __GI_time)
diff --git a/sysdeps/x86_64/multiarch/memmove.c
b/sysdeps/x86_64/multiarch/memmove.c
index ca16263..6e91025 100644
--- a/sysdeps/x86_64/multiarch/memmove.c
+++ b/sysdeps/x86_64/multiarch/memmove.c
@@ -17,7 +17,7 @@
    License along with the GNU C Library; if not, see
    <http://www.gnu.org/licenses/>.  */

-#include <string.h>
+#include <stddef.h>

 #ifndef NOT_IN_libc
 #include <shlib-compat.h>
@@ -29,20 +29,31 @@
 # define libc_hidden_builtin_def(name) \
   __hidden_ver1 (__memmove_sse2, __GI_memmove, __memmove_sse2);
 #endif
-#endif

-extern __typeof (memmove) __memmove_sse2 attribute_hidden;
-extern __typeof (memmove) __memmove_ssse3 attribute_hidden;
-extern __typeof (memmove) __memmove_ssse3_back attribute_hidden;
+/* Redefine memmove so that the compiler won't complain about the type
+   mismatch with the IFUNC selector in strong_alias, below.  */
+#undef memmove
+#define memmove __redirect_memmove
+#endif

 #include "string/memmove.c"

 #ifndef NOT_IN_libc
-libc_ifunc (memmove,
+extern __typeof (__redirect_memmove) __memmove_sse2 attribute_hidden;
+extern __typeof (__redirect_memmove) __memmove_ssse3 attribute_hidden;
+extern __typeof (__redirect_memmove) __memmove_ssse3_back attribute_hidden;
+
+/* Avoid DWARF definition DIE on ifunc symbol so that GDB can handle
+   ifunc symbol properly.  */
+extern __typeof (__redirect_memmove) __libc_memmove;
+libc_ifunc (__libc_memmove,
 	    HAS_SSSE3
 	    ? (HAS_FAST_COPY_BACKWARD
 	       ? __memmove_ssse3_back : __memmove_ssse3)
-	    : __memmove_sse2);
+	    : __memmove_sse2)
+
+#undef memmove
+strong_alias (__libc_memmove, memmove)

 #if SHLIB_COMPAT (libc, GLIBC_2_2_5, GLIBC_2_14)
 compat_symbol (libc, memmove, memcpy, GLIBC_2_2_5);
diff --git a/sysdeps/x86_64/multiarch/strstr-c.c
b/sysdeps/x86_64/multiarch/strstr-c.c
index b8ed316..795789e 100644
--- a/sysdeps/x86_64/multiarch/strstr-c.c
+++ b/sysdeps/x86_64/multiarch/strstr-c.c
@@ -7,9 +7,20 @@
   __hidden_ver1 (__strstr_sse2, __GI_strstr, __strstr_sse2);
 #endif

+/* Redefine strstr so that the compiler won't complain about the type
+   mismatch with the IFUNC selector in strong_alias, below.  */
+#undef strstr
+#define strstr __redirect_strstr
+
 #include "string/strstr.c"

-extern char *__strstr_sse42 (const char *, const char *) attribute_hidden;
-extern __typeof (__strstr_sse2) __strstr_sse2 attribute_hidden;
+extern __typeof (__redirect_strstr) __strstr_sse42 attribute_hidden;
+extern __typeof (__redirect_strstr) __strstr_sse2 attribute_hidden;
+
+/* Avoid DWARF definition DIE on ifunc symbol so that GDB can handle
+   ifunc symbol properly.  */
+extern __typeof (__redirect_strstr) __libc_strstr;
+libc_ifunc (__libc_strstr, HAS_SSE4_2 ? __strstr_sse42 : __strstr_sse2)

-libc_ifunc (strstr, HAS_SSE4_2 ? __strstr_sse42 : __strstr_sse2);
+#undef strstr
+strong_alias (__libc_strstr, strstr)


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