[hurd,commited] hurd: keep only required PLTs in ld.so
Samuel Thibault
samuel.thibault@ens-lyon.org
Wed Nov 11 01:36:49 GMT 2020
We need NO_RTLD_HIDDEN because of the need for PLT calls in ld.so.
See Roland's comment in
https://sourceware.org/bugzilla/show_bug.cgi?id=15605
"in the Hurd it's crucial that calls like __mmap be the libc ones
instead of the rtld-local ones after the bootstrap phase, when the
dynamic linker is being used for dlopen and the like."
We used to just avoid all hidden use in the rtld ; this commit switches to
keeping only those that should use PLT calls, i.e. essentially those defined in
sysdeps/mach/hurd/dl-sysdep.c:
__assert_fail
__assert_perror_fail
__*stat64
_exit
This fixes a few startup issues, notably the call to __tunable_get_val that is
made before PLTs are set up.
---
elf/dl-minimal.c | 4 ++++
include/dirent.h | 2 +-
include/libc-internal.h | 2 +-
include/libc-symbols.h | 2 +-
include/setjmp.h | 2 +-
include/signal.h | 2 +-
include/stdlib.h | 2 +-
include/string.h | 2 +-
include/sys/utsname.h | 2 +-
include/unistd.h | 2 ++
sysdeps/generic/_itoa.h | 2 +-
sysdeps/i386/dl-tlsdesc.S | 4 ----
sysdeps/mach/hurd/_exit.c | 2 ++
sysdeps/mach/hurd/dl-sysdep.c | 4 ++--
sysdeps/mach/hurd/i386/ld.abilist | 1 -
sysdeps/mach/hurd/i386/localplt.data | 15 +--------------
sysdeps/x86_64/dl-tlsdesc.S | 4 ----
17 files changed, 20 insertions(+), 34 deletions(-)
diff --git a/elf/dl-minimal.c b/elf/dl-minimal.c
index b37abfaff9..1168ac786e 100644
--- a/elf/dl-minimal.c
+++ b/elf/dl-minimal.c
@@ -292,7 +292,9 @@ Inconsistency detected by ld.so: %s: %u: %s%sAssertion `%s' failed!\n",
assertion);
}
+# ifndef NO_RTLD_HIDDEN
rtld_hidden_weak (__assert_fail)
+# endif
void weak_function
__assert_perror_fail (int errnum,
@@ -306,7 +308,9 @@ Inconsistency detected by ld.so: %s: %u: %s%sUnexpected error: %s.\n",
__strerror_r (errnum, errbuf, sizeof errbuf));
}
+# ifndef NO_RTLD_HIDDEN
rtld_hidden_weak (__assert_perror_fail)
+# endif
#endif
#undef _itoa
diff --git a/include/dirent.h b/include/dirent.h
index 8325a19e5f..f1d7e8359c 100644
--- a/include/dirent.h
+++ b/include/dirent.h
@@ -81,7 +81,7 @@ extern int __scandir64_tail (DIR *dp,
libc_hidden_proto (__rewinddir)
extern __typeof (scandirat) __scandirat;
-# if IS_IN (rtld) && !defined NO_RTLD_HIDDEN
+# if IS_IN (rtld)
extern __typeof (__rewinddir) __rewinddir attribute_hidden;
# endif
# endif
diff --git a/include/libc-internal.h b/include/libc-internal.h
index 729db7918e..915613c030 100644
--- a/include/libc-internal.h
+++ b/include/libc-internal.h
@@ -43,7 +43,7 @@ extern void __libc_thread_freeres (void);
/* Define and initialize `__progname' et. al. */
extern void __init_misc (int, char **, char **) attribute_hidden;
-# if IS_IN (rtld) && !defined NO_RTLD_HIDDEN
+# if IS_IN (rtld)
extern __typeof (__profile_frequency) __profile_frequency attribute_hidden;
# endif
diff --git a/include/libc-symbols.h b/include/libc-symbols.h
index 60153bb50d..b8103b98bb 100644
--- a/include/libc-symbols.h
+++ b/include/libc-symbols.h
@@ -643,7 +643,7 @@ for linking")
# define libc_hidden_data_ver(local, name)
#endif
-#if IS_IN (rtld) && !defined NO_RTLD_HIDDEN
+#if IS_IN (rtld)
# define rtld_hidden_proto(name, attrs...) hidden_proto (name, ##attrs)
# define rtld_hidden_tls_proto(name, attrs...) hidden_tls_proto (name, ##attrs)
# define rtld_hidden_def(name) hidden_def (name)
diff --git a/include/setjmp.h b/include/setjmp.h
index e13017edd2..0a8e4d2eaf 100644
--- a/include/setjmp.h
+++ b/include/setjmp.h
@@ -27,7 +27,7 @@ extern void __libc_longjmp (sigjmp_buf env, int val)
libc_hidden_proto (_setjmp)
libc_hidden_proto (__sigsetjmp)
-# if IS_IN (rtld) && !defined NO_RTLD_HIDDEN
+# if IS_IN (rtld)
extern __typeof (__sigsetjmp) __sigsetjmp attribute_hidden;
# endif
diff --git a/include/signal.h b/include/signal.h
index 544d701bce..2a278697c1 100644
--- a/include/signal.h
+++ b/include/signal.h
@@ -67,7 +67,7 @@ extern int __xpg_sigpause (int sig);
/* Allocate real-time signal with highest/lowest available priority. */
extern int __libc_allocate_rtsig (int __high);
-# if IS_IN (rtld) && !defined NO_RTLD_HIDDEN
+# if IS_IN (rtld)
extern __typeof (__sigaction) __sigaction attribute_hidden;
extern __typeof (__libc_sigaction) __libc_sigaction attribute_hidden;
# endif
diff --git a/include/stdlib.h b/include/stdlib.h
index ffcefd7b85..cdbdbf310d 100644
--- a/include/stdlib.h
+++ b/include/stdlib.h
@@ -310,7 +310,7 @@ struct abort_msg_s
extern struct abort_msg_s *__abort_msg;
libc_hidden_proto (__abort_msg)
-# if IS_IN (rtld) && !defined NO_RTLD_HIDDEN
+# if IS_IN (rtld)
extern __typeof (unsetenv) unsetenv attribute_hidden;
extern __typeof (__strtoul_internal) __strtoul_internal attribute_hidden;
# endif
diff --git a/include/string.h b/include/string.h
index f4ce138622..7d344d77d4 100644
--- a/include/string.h
+++ b/include/string.h
@@ -150,7 +150,7 @@ libc_hidden_builtin_proto (strspn)
libc_hidden_builtin_proto (strstr)
libc_hidden_builtin_proto (ffs)
-#if IS_IN (rtld) && !defined NO_RTLD_HIDDEN
+#if IS_IN (rtld)
extern __typeof (__stpcpy) __stpcpy attribute_hidden;
extern __typeof (__strdup) __strdup attribute_hidden;
extern __typeof (__strerror_r) __strerror_r attribute_hidden;
diff --git a/include/sys/utsname.h b/include/sys/utsname.h
index 9ed5fa2565..14f4247dd4 100644
--- a/include/sys/utsname.h
+++ b/include/sys/utsname.h
@@ -7,7 +7,7 @@ extern int __uname (struct utsname *__name);
libc_hidden_proto (uname)
libc_hidden_proto (__uname)
-# if IS_IN (rtld) && !defined NO_RTLD_HIDDEN
+# if IS_IN (rtld)
extern __typeof (__uname) __uname attribute_hidden;
# endif
#endif
diff --git a/include/unistd.h b/include/unistd.h
index f48da2c7a3..54becbc9eb 100644
--- a/include/unistd.h
+++ b/include/unistd.h
@@ -4,7 +4,9 @@
# ifndef _ISOMAC
libc_hidden_proto (_exit, __noreturn__)
+# ifndef NO_RTLD_HIDDEN
rtld_hidden_proto (_exit, __noreturn__)
+# endif
libc_hidden_proto (alarm)
extern size_t __confstr (int name, char *buf, size_t len);
libc_hidden_proto (__confstr)
diff --git a/sysdeps/generic/_itoa.h b/sysdeps/generic/_itoa.h
index 790f88a6d5..ef4de3af1b 100644
--- a/sysdeps/generic/_itoa.h
+++ b/sysdeps/generic/_itoa.h
@@ -46,7 +46,7 @@ extern char *_itoa (unsigned long long int value, char *buflim,
extern const char _itoa_upper_digits[];
extern const char _itoa_lower_digits[];
-#if IS_IN (libc) || (IS_IN (rtld) && !defined NO_RTLD_HIDDEN)
+#if IS_IN (libc) || IS_IN (rtld)
hidden_proto (_itoa_upper_digits)
hidden_proto (_itoa_lower_digits)
#endif
diff --git a/sysdeps/i386/dl-tlsdesc.S b/sysdeps/i386/dl-tlsdesc.S
index 32383e3bad..6d57739515 100644
--- a/sysdeps/i386/dl-tlsdesc.S
+++ b/sysdeps/i386/dl-tlsdesc.S
@@ -129,11 +129,7 @@ _dl_tlsdesc_dynamic:
.p2align 4,,7
.Lslow:
cfi_adjust_cfa_offset (28)
-#ifdef NO_RTLD_HIDDEN
- call JUMPTARGET (___tls_get_addr)
-#else
call HIDDEN_JUMPTARGET (___tls_get_addr)
-#endif
jmp .Lret
cfi_endproc
.size _dl_tlsdesc_dynamic, .-_dl_tlsdesc_dynamic
diff --git a/sysdeps/mach/hurd/_exit.c b/sysdeps/mach/hurd/_exit.c
index 46db06db63..f04c5d2acf 100644
--- a/sysdeps/mach/hurd/_exit.c
+++ b/sysdeps/mach/hurd/_exit.c
@@ -51,5 +51,7 @@ _exit (int status)
_hurd_exit (W_EXITCODE (status, 0));
}
libc_hidden_def (_exit)
+#ifndef NO_RTLD_HIDDEN
rtld_hidden_def (_exit)
+#endif
weak_alias (_exit, _Exit)
diff --git a/sysdeps/mach/hurd/dl-sysdep.c b/sysdeps/mach/hurd/dl-sysdep.c
index 5c0bb3124d..6b32d41c76 100644
--- a/sysdeps/mach/hurd/dl-sysdep.c
+++ b/sysdeps/mach/hurd/dl-sysdep.c
@@ -641,7 +641,8 @@ __sbrk (intptr_t increment)
return (void *) addr;
}
-check_no_hidden(__strtoul_internal);
+/* This is only used by hurdlookup for the /dev/fd/nnn magic.
+ * We avoid pulling the whole libc implementation, and we can keep this hidden. */
unsigned long int weak_function
__strtoul_internal (const char *nptr, char **endptr, int base, int group)
{
@@ -698,7 +699,6 @@ abort (void)
/* We need this alias to satisfy references from libc_pic.a objects
that were affected by the libc_hidden_proto declaration for abort. */
strong_alias (abort, __GI_abort)
-strong_alias (abort, __GI___chk_fail)
strong_alias (abort, __GI___fortify_fail)
strong_alias (abort, __GI___assert_fail)
strong_alias (abort, __GI___assert_perror_fail)
diff --git a/sysdeps/mach/hurd/i386/ld.abilist b/sysdeps/mach/hurd/i386/ld.abilist
index 2e9bf2811f..0eaea9f66d 100644
--- a/sysdeps/mach/hurd/i386/ld.abilist
+++ b/sysdeps/mach/hurd/i386/ld.abilist
@@ -9,7 +9,6 @@ GLIBC_2.2.6 __open64 F
GLIBC_2.2.6 __pread64 F
GLIBC_2.2.6 __read F
GLIBC_2.2.6 __sbrk F
-GLIBC_2.2.6 __strtoul_internal F
GLIBC_2.2.6 __write F
GLIBC_2.2.6 __writev F
GLIBC_2.2.6 __xstat64 F
diff --git a/sysdeps/mach/hurd/i386/localplt.data b/sysdeps/mach/hurd/i386/localplt.data
index b199e14e7f..abd8f31fac 100644
--- a/sysdeps/mach/hurd/i386/localplt.data
+++ b/sysdeps/mach/hurd/i386/localplt.data
@@ -37,24 +37,11 @@ ld.so: __access_noerrno
ld.so: __getpid
ld.so: __getcwd
ld.so: __sbrk
-ld.so: __strtoul_internal
-#ld.so: _exit
+ld.so: _exit ?
ld.so: abort
ld.so: _hurd_intr_rpc_mach_msg
ld.so: __errno_location
-# rtld_hidden is currently disabled to avoid having to special-case the
-# functions above which do need a PLT. These are thus currently expected.
-ld.so: _dl_allocate_tls
-ld.so: _dl_allocate_tls_init
-ld.so: _dl_exception_create
-ld.so: _dl_exception_create_format
-ld.so: _dl_exception_free
-ld.so: _dl_fatal_printf
-ld.so: _dl_find_dso_for_object
ld.so: _dl_init_first
-ld.so: _dl_mcount
-ld.so: ___tls_get_addr
-ld.so: __tunable_get_val
#
# These should ideally be avoided, but is currently difficult
libc.so: siglongjmp ?
diff --git a/sysdeps/x86_64/dl-tlsdesc.S b/sysdeps/x86_64/dl-tlsdesc.S
index 512a704fac..2535c88946 100644
--- a/sysdeps/x86_64/dl-tlsdesc.S
+++ b/sysdeps/x86_64/dl-tlsdesc.S
@@ -131,11 +131,7 @@ _dl_tlsdesc_dynamic:
movq %r10, 40(%rsp)
movq %r11, 48(%rsp)
/* %rdi already points to the tlsinfo data structure. */
-#ifdef NO_RTLD_HIDDEN
- call JUMPTARGET (__tls_get_addr)
-#else
call HIDDEN_JUMPTARGET (__tls_get_addr)
-#endif
movq 8(%rsp), %rdx
movq 16(%rsp), %rcx
movq 24(%rsp), %r8
--
2.28.0
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