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Re: PATCH: invalid IFUNC DW_AT_linkage_name: memmove strstr time
On Wed, Aug 8, 2012 at 4:16 PM, Roland McGrath <roland@hack.frob.com> wrote:
>> diff --git a/sysdeps/i386/i686/multiarch/strstr-c.c b/sysdeps/i386/i686/multiarch/strstr-c.c
>> index 1fcb00e..cbb2d8c 100644
>> --- a/sysdeps/i386/i686/multiarch/strstr-c.c
>> +++ b/sysdeps/i386/i686/multiarch/strstr-c.c
>> @@ -5,11 +5,17 @@
>> #undef libc_hidden_builtin_def
>> #define libc_hidden_builtin_def(name) \
>> __hidden_ver1 (__strstr_ia32, __GI_strstr, __strstr_ia32);
>> +#undef strstr
>> +#define strstr __redirect_strstr
>
> What are these lines doing? I guess they are to avoid seeing the normal
> <string.h> declaration of strstr so the compiler doesn't complain about the
> type mismatch when it's defined by strong_alias. Since it's a subtle
> weirdness, it requires a comment. Since they aren't directly related to
> the libc_hidden_builtin_def bit, separate from that with a blank line.
>
>> -libc_ifunc (strstr, HAS_SSE4_2 ? __strstr_sse42 : __strstr_ia32);
>> +libc_ifunc (__libc_strstr, HAS_SSE4_2 ? __strstr_sse42 : __strstr_ia32);
>
> No trailing ; after libc_ifunc (it was wrong here before).
>
>> +#undef strstr
>> +strong_alias (__libc_strstr, strstr);
>
> No trailing ; after strong_alias.
>
>> +# undef time
>> +# define time __redirect_time
>> +# include <time.h>
>
> Again, needs comment.
>
>> +# include <dl-vdso.h>
>
> Why is this needed?
>
>> @@ -28,22 +28,28 @@
>> # undef libc_hidden_builtin_def
>> # define libc_hidden_builtin_def(name) \
>> __hidden_ver1 (__memmove_sse2, __GI_memmove, __memmove_sse2);
>> +# undef memmove
>> +# define memmove __redirect_memmove
>
> Blank line, comment.
>
>> -extern __typeof (memmove) __memmove_sse2 attribute_hidden;
>> -extern __typeof (memmove) __memmove_ssse3 attribute_hidden;
>> -extern __typeof (memmove) __memmove_ssse3_back attribute_hidden;
>> +extern void *__memmove_sse2 (void *, const void *, size_t) attribute_hidden;
>> +extern __typeof (__memmove_sse2) __memmove_ssse3 attribute_hidden;
>> +extern __typeof (__memmove_sse2) __memmove_ssse3_back attribute_hidden;
>
> It should still use __typeof throughout.
> You can just refer to __redirect_memmove now.
>
>> +extern __typeof (__memmove_sse2) __libc_memmove;
>
> And here.
>
>> +strong_alias (__libc_memmove, memmove);
>
> No trailing ;.
>
>> @@ -5,11 +5,17 @@
>> # undef libc_hidden_builtin_def
>> # define libc_hidden_builtin_def(name) \
>> __hidden_ver1 (__strstr_sse2, __GI_strstr, __strstr_sse2);
>> +# undef strstr
>> +# define strstr __redirect_strstr
>
> Blank line, comment.
>
>> #endif
>>
>> #include "string/strstr.c"
>>
>> extern char *__strstr_sse42 (const char *, const char *) attribute_hidden;
>> extern __typeof (__strstr_sse2) __strstr_sse2 attribute_hidden;
>> +extern __typeof (__strstr_sse2) __libc_strstr;
>
> Change these to all use __typeof (__redirect_strstr).
>
>> -libc_ifunc (strstr, HAS_SSE4_2 ? __strstr_sse42 : __strstr_sse2);
>> +libc_ifunc (__libc_strstr, HAS_SSE4_2 ? __strstr_sse42 : __strstr_sse2);
>> +
>> +#undef strstr
>> +strong_alias (__libc_strstr, strstr);
>
> No trailing ; on libc_ifunc and strong_alias.
Here is the updated patch. OK to install?
Thanks.
--
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..d1922df 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 compiler won't complain the type mismatch
+ from 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..c9b34bd 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 compiler won't complain the type mismatch
+ from 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 time_t __GI_time (time_t *);
+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..93e8399 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 compiler won't complain the type mismatch
+ from 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..fd3d324 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 compiler won't complain the type mismatch
+ from 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)