If libc_hidden_builtin_{def,proto} isn't properly set for *_chk routines,
there are unwanted PLT entries in libc.so.
There is a special case with __asprintf_chk:
If ldbl_* macros are used for asprintf, ABI gets broken on s390x,
if it isn't, ppc64le isn't building due to multiple asm redirections.
This is due to the inclusion of bits/stdio-lbdl.h for ppc64le whereas it
isn't for s390x. This header creates redirections, which are not
compatible with the ones generated using libc_hidden_def.
Yet, we can't use libc_hidden_ldbl_proto on s390x since it will not
create a simple strong alias (e.g. as done on x86_64), but a versioned
alias, leading to ABI breakage.
This results in errors on s390x:
/usr/bin/ld: glibc/iconv/../libio/bits/stdio2.h:137: undefined reference
to `__asprintf_chk'
Original __asprintf_chk symbols:
00000000001395b0 T __asprintf_chk
0000000000177e90 T __nldbl___asprintf_chk
__asprintf_chk symbols with ldbl_* macros:
000000000012d590 t ___asprintf_chk
000000000012d590 t __asprintf_chk@@GLIBC_2.4
000000000012d590 t __GI___asprintf_chk
000000000012d590 t __GL____asprintf_chk___asprintf_chk
0000000000172240 T __nldbl___asprintf_chk
__asprintf_chk symbols with the patch:
000000000012d590 t ___asprintf_chk
000000000012d590 T __asprintf_chk
000000000012d590 t __GI___asprintf_chk
0000000000172240 T __nldbl___asprintf_chk
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
/* Write formatted output from FORMAT to a string which is
allocated with malloc and stored in *STRING_PTR. */
int
-__asprintf_chk (char **result_ptr, int flag, const char *format, ...)
+___asprintf_chk (char **result_ptr, int flag, const char *format, ...)
{
/* For flag > 0 (i.e. __USE_FORTIFY_LEVEL > 1) request that %n
can only come from read-only format strings. */
return ret;
}
+#if defined __LDBL_COMPAT || __LDOUBLE_REDIRECTS_TO_FLOAT128_ABI == 1
+/* This is needed since <bits/stdio-lbdl.h> is included in this case, leading to
+ * multiple asm redirection of the same symbol
+ */
+ldbl_hidden_def (___asprintf_chk, __asprintf_chk)
+ldbl_strong_alias (___asprintf_chk, __asprintf_chk)
+#else
+/* On some systems introduction of ldbl_* macros lead to ABI breakage due to the
+ * long_double_symbol aliasing, e.g. on s390x:
+ * /usr/bin/ld: glibc/iconv/../libio/bits/stdio2.h:137: undefined reference to
+ * `__asprintf_chk'
+ * Due to __asprintf_chk@@GLIBC_2.4 alias replacing __asprintf_chk.
+ */
+strong_alias (___asprintf_chk, __asprintf_chk)
+libc_hidden_def (__asprintf_chk)
+#endif
fp->_flags |= old_error;
return result;
}
+libc_hidden_builtin_def (__fgets_unlocked_chk)
return ret;
}
+ldbl_hidden_def (___fprintf_chk, __fprintf_chk)
ldbl_strong_alias (___fprintf_chk, __fprintf_chk)
return ret;
}
+ldbl_hidden_def (___sprintf_chk, __sprintf_chk)
ldbl_strong_alias (___sprintf_chk, __sprintf_chk)
libc_hidden_proto (__open_memstream)
libc_hidden_proto (__libc_fatal)
rtld_hidden_proto (__libc_fatal)
-libc_hidden_proto (__vsprintf_chk)
+
+libc_hidden_proto (__fgets_unlocked_chk)
+
+#if defined __LDBL_COMPAT || __LDOUBLE_REDIRECTS_TO_FLOAT128_ABI == 1
+libc_hidden_ldbl_proto (__asprintf_chk)
+#else
+libc_hidden_proto (__asprintf_chk)
+#endif
+
+libc_hidden_ldbl_proto (__fprintf_chk)
+libc_hidden_ldbl_proto (__sprintf_chk)
+libc_hidden_ldbl_proto (__vsprintf_chk)
extern FILE * __fmemopen (void *buf, size_t len, const char *mode);
libc_hidden_proto (__fmemopen)
return done;
}
+hidden_def (___ieee128___asprintf_chk)
strong_alias (___ieee128___asprintf_chk, __asprintf_chkieee128)
return done;
}
+hidden_def (___ieee128___fprintf_chk)
strong_alias (___ieee128___fprintf_chk, __fprintf_chkieee128)
return done;
}
+hidden_def (___ieee128___sprintf_chk)
strong_alias (___ieee128___sprintf_chk, __sprintf_chkieee128)
return __vsprintf_internal (string, slen, format, ap, mode);
}
+hidden_def (___ieee128___vsprintf_chk)
strong_alias (___ieee128___vsprintf_chk, __vsprintf_chkieee128)