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Re: [PATCH] ld.so: Introduce struct dl_exception
- From: Florian Weimer <fweimer at redhat dot com>
- To: libc-alpha at sourceware dot org
- Date: Thu, 10 Aug 2017 13:56:34 +0200
- Subject: Re: [PATCH] ld.so: Introduce struct dl_exception
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- References: <20170619152936.C6D63402AEC2B@oldenburg.str.redhat.com>
On 06/19/2017 05:29 PM, Florian Weimer wrote:> This commit separates allocating and raising exceptions. This> simplifies catching and re-raising them because it is no longer> necessary to make a temporary, on-stack copy of the exception message.Ping?I rebased the attached patch to current master.I plan to remove the old handler functions in a subsequent patch. Thispatch only removes the alloca-based string manipulation, but leaves someuses of the legacy interfaces in place.Thanks,Florian
ld.so: Introduce struct dl_exceptionThis commit separates allocating and raising exceptions. Thissimplifies catching and re-raising them because it is no longernecessary to make a temporary, on-stack copy of the exception message.2017-08-10 Florian Weimer <fweimer@redhat.com>Introduce ld.so exceptions.* sysdeps/generic/ldsodefs.h (struct dl_exception): Define.(_dl_exception_create, _dl_exception_create_format)(_dl_exception_free, _dl_signal_exception, _dl_signal_cexception)(_dl_catch_exception): Declare.(_dl_catch_error): Update comment.* elf/dl-error-skeleton.c (struct catch): Replace objname,errstring, malloced members with exception member.(_dl_out_of_memory): Remove.(fatal_error): New function, extracted from _dl_signal_error.(_dl_signal_exception, _dl_signal_cexception): New functions.(_dl_signal_error): Call _dl_exception_create to allocate anexception object.(_dl_catch_exception): New function, based on _dl_catch_error.(_dl_catch_error): Implement using _dl_catch_exception.* elf/dl-exception.c: New file.* elf/Makefile (dl-routines): Add dl-exception.(elide-routines.os): Likewise.* elf/Version (ld/GLIBC_PRIVATE): Add _dl_exception_create,_dl_exception_create_format, _dl_exception_free.* elf/dl-deps.c (_dl_map_object_deps): Use _dl_catch_exception and_dl_signal_exception.* elf/dl-lookup.c (make_string): Remove.(_dl_lookup_symbol_x): Use _dl_exception_create_format,_dl_signal_cexception, _dl_exception_free.* elf/dl-open.c (_dl_open): Use _dl_catch_exception and_dl_signal_exception.* elf/dl-sym.c (do_sym): Likewise.* elf/dl-version.c (make_string): Remove.(match_symbol): Use _dl_exception_create_format,_dl_signal_cexception, _dl_exception_free.(_dl_check_map_versions): Likewise.* sysdeps/generic/localplt.data (ld.so): Add _dl_signal_exception,_dl_catch_exception.* sysdeps/unix/sysv/linux/aarch64/localplt.data (ld.so): Likewise.* sysdeps/unix/sysv/linux/alpha/localplt.data (ld.so): Likewise.* sysdeps/unix/sysv/linux/arm/localplt.data (ld.so): Likewise.* sysdeps/unix/sysv/linux/hppa/localplt.data (ld.so): Likewise.* sysdeps/unix/sysv/linux/i386/localplt.data (ld.so): Likewise.* sysdeps/unix/sysv/linux/ia64/localplt.data (ld.so): Likewise.* sysdeps/unix/sysv/linux/m68k/localplt.data (ld.so): Likewise.* sysdeps/unix/sysv/linux/microblaze/localplt.data (ld.so):Likewise.* sysdeps/unix/sysv/linux/nios2/localplt.data (ld.so): Likewise.* sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/localplt.data(ld.so): Likewise.* sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/localplt.data(ld.so): Likewise.* sysdeps/unix/sysv/linux/powerpc/powerpc64/localplt.data (ld.so):Likewise.* sysdeps/unix/sysv/linux/s390/localplt.data (ld.so): Likewise.* sysdeps/unix/sysv/linux/sh/localplt.data (ld.so): Likewise.* sysdeps/unix/sysv/linux/sparc/sparc32/localplt.data (ld.so):Likewise.* sysdeps/unix/sysv/linux/sparc/sparc64/localplt.data (ld.so):Likewise.* sysdeps/x86_64/localplt.data (ld.so): Likewise.diff --git a/elf/Makefile b/elf/Makefileindex b54ebf8a98..d314a5fa7e 100644--- a/elf/Makefile+++ b/elf/Makefile@@ -31,7 +31,8 @@ routines= $(all-dl-routines) dl-support dl-iteratephdr \ dl-routines= $(addprefix dl-,load lookup object reloc deps hwcaps \ runtime init fini debug misc \ version profile tls origin scope \- execstack caller open close trampoline)+ execstack caller open close trampoline \+ exception) ifeq (yes,$(use-ldconfig)) dl-routines += dl-cache endif@@ -51,7 +52,7 @@ endif all-dl-routines = $(dl-routines) $(sysdep-dl-routines) # But they are absent from the shared libc, because that code is in ld.so. elide-routines.os = $(all-dl-routines) dl-support enbl-secure dl-origin \- dl-sysdep+ dl-sysdep dl-exception shared-only-routines += dl-caller # ld.so uses those routines, plus some special stuff for being the programdiff --git a/elf/Versions b/elf/Versionsindex e65f2fac20..79ffaf73d2 100644--- a/elf/Versions+++ b/elf/Versions@@ -28,6 +28,7 @@ libc { __libc_dlclose; __libc_dlopen_mode; __libc_dlsym; # Internal error handling support. Interposes the functions in ld.so.+ _dl_signal_exception; _dl_catch_exception; _dl_signal_error; _dl_catch_error; } }@@ -68,7 +69,11 @@ ld { # Pointer protection. __pointer_chk_guard; + # Internal error handling support.+ _dl_exception_create; _dl_exception_create_format; _dl_exception_free;+ # Internal error handling support. Interposed by libc.so.+ _dl_signal_exception; _dl_catch_exception; _dl_signal_error; _dl_catch_error; # Set value of a tunable.diff --git a/elf/dl-deps.c b/elf/dl-deps.cindex 1b8bac6593..7c82d42be9 100644--- a/elf/dl-deps.c+++ b/elf/dl-deps.c@@ -165,8 +165,7 @@ _dl_map_object_deps (struct link_map *map, const char *name; int errno_saved; int errno_reason;- const char *errstring;- const char *objname;+ struct dl_exception exception; /* No loaded object so far. */ nlist = 0;@@ -200,7 +199,6 @@ _dl_map_object_deps (struct link_map *map, alloca means we cannot use recursive function calls. */ errno_saved = errno; errno_reason = 0;- errstring = NULL; errno = 0; name = NULL; for (runp = known; runp; )@@ -250,17 +248,9 @@ _dl_map_object_deps (struct link_map *map, /* Store the tag in the argument structure. */ args.name = name; -bool malloced;-int err = _dl_catch_error (&objname, &errstring, &malloced,- openaux, &args);-if (__glibc_unlikely (errstring != NULL))+int err = _dl_catch_exception (&exception, openaux, &args);+if (__glibc_unlikely (exception.errstring != NULL)) {- char *new_errstring = strdupa (errstring);- objname = strdupa (objname);- if (malloced)- free ((char *) errstring);- errstring = new_errstring;- if (err) errno_reason = err; else@@ -313,31 +303,18 @@ _dl_map_object_deps (struct link_map *map, /* We must be prepared that the addressed shared object is not available. For filter objects the dependency must be available. */-bool malloced;-int err = _dl_catch_error (&objname, &errstring, &malloced,-openaux, &args);--if (__glibc_unlikely (errstring != NULL))+int err = _dl_catch_exception (&exception, openaux, &args);+if (__glibc_unlikely (exception.errstring != NULL)) { if (d->d_tag == DT_AUXILIARY) { /* We are not interested in the error message. */-assert (errstring != NULL);-if (malloced)- free ((char *) errstring);-+_dl_exception_free (&exception); /* Simply ignore this error and continue the work. */ continue; } else {--char *new_errstring = strdupa (errstring);-objname = strdupa (objname);-if (malloced)- free ((char *) errstring);-errstring = new_errstring;- if (err) errno_reason = err; else@@ -683,6 +660,6 @@ Filters not supported with LD_TRACE_PRELINKING")); _dl_scope_free (old_l_initfini); if (errno_reason)- _dl_signal_error (errno_reason == -1 ? 0 : errno_reason, objname,- NULL, errstring);+ _dl_signal_exception (errno_reason == -1 ? 0 : errno_reason,+ &exception, NULL); }diff --git a/elf/dl-error-skeleton.c b/elf/dl-error-skeleton.cindex 8e5888d4bd..8de6c87abf 100644--- a/elf/dl-error-skeleton.c+++ b/elf/dl-error-skeleton.c@@ -39,10 +39,7 @@ _dl_signal_error. */ struct catch {- const char **objname;/* Object/File name. */- const char **errstring;/* Error detail filled in here. */- bool *malloced;/* Nonzero if the string is malloced- by the libc malloc. */+ struct dl_exception *exception; /* The exception data is stored there. */ volatile int *errcode;/* Return value of _dl_signal_error. */ jmp_buf env;/* longjmp here on error. */ };@@ -60,11 +57,6 @@ static __thread struct catch *catch_hook attribute_tls_model_ie; static struct catch *catch_hook; #endif -/* This message we return as a last resort. We define the string in a- variable since we have to avoid freeing it and so have to enable- a pointer comparison. See below and in dlfcn/dlerror.c. */-static const char _dl_out_of_memory[] = "out of memory";- #if DL_ERROR_BOOTSTRAP /* This points to a function which is called when an continuable error is received. Unlike the handling of `catch' this function may return.@@ -76,6 +68,41 @@ static const char _dl_out_of_memory[] = "out of memory"; static receiver_fct receiver; #endif /* DL_ERROR_BOOTSTRAP */ +/* Lossage while resolving the program's own symbols is always fatal. */+static void+__attribute__ ((noreturn))+fatal_error (int errcode, const char *objname, const char *occasion,+ const char *errstring)+{+ char buffer[1024];+ _dl_fatal_printf ("%s: %s: %s%s%s%s%s\n",+ RTLD_PROGNAME,+ occasion ?: N_("error while loading shared libraries"),+ objname, *objname ? ": " : "",+ errstring, errcode ? ": " : "",+ (errcode+ ? __strerror_r (errcode, buffer, sizeof buffer)+ : ""));+}++void+_dl_signal_exception (int errcode, struct dl_exception *exception,+ const char *occasion)+{+ struct catch *lcatch = catch_hook;+ if (lcatch != NULL)+ {+ *lcatch->exception = *exception;+ *lcatch->errcode = errcode;++ /* We do not restore the signal mask because none was saved. */+ __longjmp (lcatch->env[0].__jmpbuf, 1);+ }+ else+ fatal_error (errcode, exception->objname, occasion, exception->errstring);+}+libc_hidden_def (_dl_signal_exception)+ void internal_function _dl_signal_error (int errcode, const char *objname, const char *occation,@@ -86,66 +113,43 @@ _dl_signal_error (int errcode, const char *objname, const char *occation, if (! errstring) errstring = N_("DYNAMIC LINKER BUG!!!"); - if (objname == NULL)- objname = ""; if (lcatch != NULL) {- /* We are inside _dl_catch_error. Return to it. We have to- duplicate the error string since it might be allocated on the- stack. The object name is always a string constant. */- size_t len_objname = strlen (objname) + 1;- size_t len_errstring = strlen (errstring) + 1;-- char *errstring_copy = malloc (len_objname + len_errstring);- if (errstring_copy != NULL)-{- /* Make a copy of the object file name and the error string. */- *lcatch->objname = memcpy (__mempcpy (errstring_copy,-errstring, len_errstring),- objname, len_objname);- *lcatch->errstring = errstring_copy;-- /* If the main executable is relocated it means the libc's malloc- is used. */- bool malloced = true;-#ifdef SHARED- malloced = (GL(dl_ns)[LM_ID_BASE]._ns_loaded != NULL- && (GL(dl_ns)[LM_ID_BASE]._ns_loaded->l_relocated != 0));-#endif- *lcatch->malloced = malloced;-}- else-{- /* This is better than nothing. */- *lcatch->objname = "";- *lcatch->errstring = _dl_out_of_memory;- *lcatch->malloced = false;-}-+ _dl_exception_create (lcatch->exception, objname, errstring); *lcatch->errcode = errcode; /* We do not restore the signal mask because none was saved. */ __longjmp (lcatch->env[0].__jmpbuf, 1); } else- {- /* Lossage while resolving the program's own symbols is always fatal. */- char buffer[1024];- _dl_fatal_printf ("%s: %s: %s%s%s%s%s\n",-RTLD_PROGNAME,-occation ?: N_("error while loading shared libraries"),-objname, *objname ? ": " : "",-errstring, errcode ? ": " : "",-(errcode- ? __strerror_r (errcode, buffer, sizeof buffer)- : ""));- }+ fatal_error (errcode, objname, occation, errstring); } libc_hidden_def (_dl_signal_error) #if DL_ERROR_BOOTSTRAP void+_dl_signal_cexception (int errcode, struct dl_exception *exception,+ const char *occasion)+{+ if (__builtin_expect (GLRO(dl_debug_mask)+& ~(DL_DEBUG_STATISTICS|DL_DEBUG_PRELINK), 0))+ _dl_debug_printf ("%s: error: %s: %s (%s)\n",+ exception->objname, occasion,+ exception->errstring, receiver ? "continued" : "fatal");++ if (receiver)+ {+ /* We are inside _dl_receive_error. Call the user supplied+ handler and resume the work. The receiver will still be+ installed. */+ (*receiver) (errcode, exception->objname, exception->errstring);+ }+ else+ _dl_signal_exception (errcode, exception, occasion);+}++void internal_function _dl_signal_cerror (int errcode, const char *objname, const char *occation, const char *errstring)@@ -167,11 +171,9 @@ _dl_signal_cerror (int errcode, const char *objname, const char *occation, } #endif /* DL_ERROR_BOOTSTRAP */ - int-internal_function-_dl_catch_error (const char **objname, const char **errstring,- bool *mallocedp, void (*operate) (void *), void *args)+_dl_catch_exception (struct dl_exception *exception,+ void (*operate) (void *), void *args) { /* We need not handle `receiver' since setting a `catch' is handled before it. */@@ -184,9 +186,7 @@ _dl_catch_error (const char **objname, const char **errstring, struct catch c; /* Don't use an initializer since we don't need to clear C.env. */- c.objname = objname;- c.errstring = errstring;- c.malloced = mallocedp;+ c.exception = exception; c.errcode = &errcode; struct catch *const old = catch_hook;@@ -197,17 +197,30 @@ _dl_catch_error (const char **objname, const char **errstring, { (*operate) (args); catch_hook = old;- *objname = NULL;- *errstring = NULL;- *mallocedp = false;+ *exception = (struct dl_exception) { NULL }; return 0; } - /* We get here only if we longjmp'd out of OPERATE. _dl_signal_error has- already stored values into *OBJNAME, *ERRSTRING, and *MALLOCEDP. */+ /* We get here only if we longjmp'd out of OPERATE.+ _dl_signal_exception has already stored values into+ *EXCEPTION. */ catch_hook = old; return errcode; }+libc_hidden_def (_dl_catch_exception)++int+internal_function+_dl_catch_error (const char **objname, const char **errstring,+ bool *mallocedp, void (*operate) (void *), void *args)+{+ struct dl_exception exception;+ int errorcode = _dl_catch_exception (&exception, operate, args);+ *objname = exception.objname;+ *errstring = exception.errstring;+ *mallocedp = exception.message_buffer == exception.errstring;+ return errorcode;+} libc_hidden_def (_dl_catch_error) #if DL_ERROR_BOOTSTRAPdiff --git a/elf/dl-exception.c b/elf/dl-exception.cnew file mode 100644index 0000000000..b4d0ca7578--- /dev/null+++ b/elf/dl-exception.c@@ -0,0 +1,202 @@+/* ld.so error exception allocation and deallocation.+ Copyright (C) 1995-2017 Free Software Foundation, Inc.+ This file is part of the GNU C Library.++ The GNU C Library is free software; you can redistribute it and/or+ modify it under the terms of the GNU Lesser General Public+ License as published by the Free Software Foundation; either+ version 2.1 of the License, or (at your option) any later version.++ The GNU C Library is distributed in the hope that it will be useful,+ but WITHOUT ANY WARRANTY; without even the implied warranty of+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU+ Lesser General Public License for more details.++ You should have received a copy of the GNU Lesser General Public+ License along with the GNU C Library; if not, see+ <http://www.gnu.org/licenses/>. */++#include <ldsodefs.h>+#include <limits.h>+#include <stdarg.h>+#include <stdbool.h>+#include <stdint.h>+#include <string.h>+#include <unistd.h>++/* This message we return as a last resort. We define the string in a+ variable since we have to avoid freeing it and so have to enable+ a pointer comparison. See below and in dlfcn/dlerror.c. */+static const char _dl_out_of_memory[] = "out of memory";++/* Dummy allocation object used if allocating the message buffer+ fails. */+static void+oom_exception (struct dl_exception *exception)+{+ exception->objname = "";+ exception->errstring = _dl_out_of_memory;+ exception->message_buffer = NULL;+}++static void+__attribute__ ((noreturn))+length_mismatch (void)+{+ _dl_fatal_printf ("Fatal error: "+ "length accounting in _dl_exception_create_format\n");+}++/* Adjust the message buffer to indicate whether it is possible to+ free it. EXCEPTION->errstring must be a potentially deallocatable+ pointer. */+static void+adjust_message_buffer (struct dl_exception *exception)+{+ /* If the main executable is relocated it means the libc's malloc+ is used. */+ bool malloced = true;+#ifdef SHARED+ malloced = (GL(dl_ns)[LM_ID_BASE]._ns_loaded != NULL+ && (GL(dl_ns)[LM_ID_BASE]._ns_loaded->l_relocated != 0));+#endif+ if (malloced)+ exception->message_buffer = (char *) exception->errstring;+ else+ exception->message_buffer = NULL;+}++void+_dl_exception_create (struct dl_exception *exception, const char *objname,+ const char *errstring)+{+ if (objname == NULL)+ objname = "";+ size_t len_objname = strlen (objname) + 1;+ size_t len_errstring = strlen (errstring) + 1;+ char *errstring_copy = malloc (len_objname + len_errstring);+ if (errstring_copy != NULL)+ {+ /* Make a copy of the object file name and the error string. */+ exception->objname = memcpy (__mempcpy (errstring_copy,+ errstring, len_errstring),+ objname, len_objname);+ exception->errstring = errstring_copy;+ adjust_message_buffer (exception);+ }+ else+ oom_exception (exception);+}+rtld_hidden_def (_dl_exception_create)++void+_dl_exception_create_format (struct dl_exception *exception, const char *objname,+ const char *fmt, ...)+{+ if (objname == NULL)+ objname = "";+ size_t len_objname = strlen (objname) + 1;+ /* Compute the length of the result. Include room for two NUL+ bytes. */+ size_t length = len_objname + 1;+ {+ va_list ap;+ va_start (ap, fmt);+ for (const char *p = fmt; *p != '\0'; ++p)+ if (*p == '%')+ {+ ++p;+ switch (*p)+ {+ case 's':+ length += strlen (va_arg (ap, const char *));+ break;+ default:+ /* Assumed to be '%'. */+ ++length;+ break;+ }+ }+ else+ ++length;+ va_end (ap);+ }++ if (length > PTRDIFF_MAX)+ {+ oom_exception (exception);+ return;+ }+ char *errstring = malloc (length);+ if (errstring == NULL)+ {+ oom_exception (exception);+ return;+ }+ exception->errstring = errstring;+ adjust_message_buffer (exception);++ /* Copy the error message to errstring. */+ {+ /* Next byte to be written in errstring. */+ char *wptr = errstring;+ /* End of the allocated string. */+ char *const end = errstring + length;++ va_list ap;+ va_start (ap, fmt);++ for (const char *p = fmt; *p != '\0'; ++p)+ if (*p == '%')+ {+ ++p;+ switch (*p)+ {+ case 's':+ {+ const char *ptr = va_arg (ap, const char *);+ size_t len_ptr = strlen (ptr);+ if (len_ptr > end - wptr)+ length_mismatch ();+ wptr = __mempcpy (wptr, ptr, len_ptr);+ }+ break;+ case '%':+ if (wptr == end)+ length_mismatch ();+ *wptr = '%';+ ++wptr;+ break;+ default:+ _dl_fatal_printf ("Fatal error:"+ " invalid format in exception string\n");+ }+ }+ else+ {+ if (wptr == end)+ length_mismatch ();+ *wptr = *p;+ ++wptr;+ }++ if (wptr == end)+ length_mismatch ();+ *wptr = '\0';+ ++wptr;+ if (len_objname != end - wptr)+ length_mismatch ();+ exception->objname = memcpy (wptr, objname, len_objname);+ }+}+rtld_hidden_def (_dl_exception_create_format)++void+_dl_exception_free (struct dl_exception *exception)+{+ free (exception->message_buffer);+ exception->objname = NULL;+ exception->errstring = NULL;+ exception->message_buffer = NULL;+}+rtld_hidden_def (_dl_exception_free)diff --git a/elf/dl-lookup.c b/elf/dl-lookup.cindex 3d2369dbf2..645dc3ebb4 100644--- a/elf/dl-lookup.c+++ b/elf/dl-lookup.c@@ -47,23 +47,6 @@ struct sym_val }; -#define make_string(string, rest...) \- ({ \- const char *all[] = { string, ## rest }; \- size_t len, cnt; \- char *result, *cp; \- \- len = 1; \- for (cnt = 0; cnt < sizeof (all) / sizeof (all[0]); ++cnt) \- len += strlen (all[cnt]); \- \- cp = result = alloca (len); \- for (cnt = 0; cnt < sizeof (all) / sizeof (all[0]); ++cnt) \- cp = __stpcpy (cp, all[cnt]); \- \- result; \- })- /* Statistics function. */ #ifdef SHARED # define bump_num_relocations() ++GL(dl_num_relocations)@@ -843,17 +826,16 @@ _dl_lookup_symbol_x (const char *undef_name, struct link_map *undef_map, for unversioned lookups. */ assert (version != NULL); const char *reference_name = undef_map ? undef_map->l_name : "";-+ struct dl_exception exception; /* XXX We cannot translate the message. */- _dl_signal_cerror (0, DSO_FILENAME (reference_name),- N_("relocation error"),- make_string ("symbol ", undef_name, ", version ",- version->name,- " not defined in file ",- version->filename,- " with link time reference",- res == -2- ? " (no version symbols)" : ""));+ _dl_exception_create_format+ (&exception, DSO_FILENAME (reference_name),+ "symbol %s version %s not defined in file %s"+ " with link time reference%s",+ undef_name, version->name, version->filename,+ res == -2 ? " (no version symbols)" : "");+ _dl_signal_cexception (0, &exception, N_("relocation error"));+ _dl_exception_free (&exception); *ref = NULL; return 0; }@@ -869,12 +851,14 @@ _dl_lookup_symbol_x (const char *undef_name, struct link_map *undef_map, const char *versionstr = version ? ", version " : ""; const char *versionname = (version && version->name ? version->name : "");-+ struct dl_exception exception; /* XXX We cannot translate the message. */- _dl_signal_cerror (0, DSO_FILENAME (reference_name),- N_("symbol lookup error"),- make_string ("undefined symbol: ", undef_name,- versionstr, versionname));+ _dl_exception_create_format+ (&exception, DSO_FILENAME (reference_name),+ "undefined symbol: %s%s%s",+ undef_name, versionstr, versionname);+ _dl_signal_cexception (0, &exception, N_("symbol lookup error"));+ _dl_exception_free (&exception); } *ref = NULL; return 0;diff --git a/elf/dl-open.c b/elf/dl-open.cindex cec54db413..91a1d1a4f8 100644--- a/elf/dl-open.c+++ b/elf/dl-open.c@@ -643,11 +643,8 @@ no more namespaces available for dlmopen()")); args.argv = argv; args.env = env; - const char *objname;- const char *errstring;- bool malloced;- int errcode = _dl_catch_error (&objname, &errstring, &malloced,- dl_open_worker, &args);+ struct dl_exception exception;+ int errcode = _dl_catch_exception (&exception, dl_open_worker, &args); #if defined USE_LDCONFIG && !defined MAP_COPY /* We must unmap the cache file. */@@ -655,7 +652,7 @@ no more namespaces available for dlmopen()")); #endif /* See if an error occurred during loading. */- if (__glibc_unlikely (errstring != NULL))+ if (__glibc_unlikely (exception.errstring != NULL)) { /* Remove the object from memory. It may be in an inconsistent state if relocation failed, for example. */@@ -679,28 +676,8 @@ no more namespaces available for dlmopen()")); /* Release the lock. */ __rtld_lock_unlock_recursive (GL(dl_load_lock)); - /* Make a local copy of the error string so that we can release the- memory allocated for it. */- size_t len_errstring = strlen (errstring) + 1;- char *local_errstring;- if (objname == errstring + len_errstring)-{- size_t total_len = len_errstring + strlen (objname) + 1;- local_errstring = alloca (total_len);- memcpy (local_errstring, errstring, total_len);- objname = local_errstring + len_errstring;-}- else-{- local_errstring = alloca (len_errstring);- memcpy (local_errstring, errstring, len_errstring);-}-- if (malloced)-free ((char *) errstring);- /* Reraise the error. */- _dl_signal_error (errcode, objname, NULL, local_errstring);+ _dl_signal_exception (errcode, &exception, NULL); } assert (_dl_debug_initialize (0, args.nsid)->r_state == RT_CONSISTENT);diff --git a/elf/dl-sym.c b/elf/dl-sym.cindex 7cd6e97643..fb54a91858 100644--- a/elf/dl-sym.c+++ b/elf/dl-sym.c@@ -119,26 +119,11 @@ do_sym (void *handle, const char *name, void *who, args.refp = &ref; THREAD_GSCOPE_SET_FLAG ();-- const char *objname;- const char *errstring = NULL;- bool malloced;- int err = _dl_catch_error (&objname, &errstring, &malloced,- call_dl_lookup, &args);-+ struct dl_exception exception;+ int err = _dl_catch_exception (&exception, call_dl_lookup, &args); THREAD_GSCOPE_RESET_FLAG ();-- if (__glibc_unlikely (errstring != NULL))- {- /* The lookup was unsuccessful. Rethrow the error. */- char *errstring_dup = strdupa (errstring);- char *objname_dup = strdupa (objname);- if (malloced)-free ((char *) errstring);-- _dl_signal_error (err, objname_dup, NULL, errstring_dup);- /* NOTREACHED */- }+ if (__glibc_unlikely (exception.errstring != NULL))+ _dl_signal_exception (err, &exception, NULL); result = args.map; }diff --git a/elf/dl-version.c b/elf/dl-version.cindex c00078e5e4..c0d76ad42a 100644--- a/elf/dl-version.c+++ b/elf/dl-version.c@@ -27,25 +27,6 @@ #include <assert.h> --#define make_string(string, rest...) \- ({ \- const char *all[] = { string, ## rest }; \- size_t len, cnt; \- char *result, *cp; \- \- len = 1; \- for (cnt = 0; cnt < sizeof (all) / sizeof (all[0]); ++cnt) \- len += strlen (all[cnt]); \- \- cp = result = alloca (len); \- for (cnt = 0; cnt < sizeof (all) / sizeof (all[0]); ++cnt) \- cp = __stpcpy (cp, all[cnt]); \- \- result; \- })-- static inline struct link_map * __attribute ((always_inline)) find_needed (const char *name, struct link_map *map)@@ -78,8 +59,8 @@ match_symbol (const char *name, Lmid_t ns, ElfW(Word) hash, const char *string, ElfW(Addr) def_offset; ElfW(Verdef) *def; /* Initialize to make the compiler happy. */- const char *errstring = NULL; int result = 0;+ struct dl_exception exception; /* Display information about what we are doing while debugging. */ if (__glibc_unlikely (GLRO(dl_debug_mask) & DL_DEBUG_VERSIONS))@@ -96,8 +77,9 @@ checking for version `%s' in file %s [%lu] required by file %s [%lu]\n", if (verbose) { /* XXX We cannot translate the messages. */- errstring = make_string ("\-no version information available (required by ", name, ")");+ _dl_exception_create_format+ (&exception, DSO_FILENAME (map->l_name),+ "no version information available (required by %s)", name); goto call_cerror; } return 0;@@ -116,10 +98,10 @@ no version information available (required by ", name, ")"); char buf[20]; buf[sizeof (buf) - 1] = '\0'; /* XXX We cannot translate the message. */- errstring = make_string ("unsupported version ",- _itoa (def->vd_version,- &buf[sizeof (buf) - 1], 10, 0),- " of Verdef record");+ _dl_exception_create_format+ (&exception, DSO_FILENAME (map->l_name),+ "unsupported version %s of Verdef record",+ _itoa (def->vd_version, &buf[sizeof (buf) - 1], 10, 0)); result = 1; goto call_cerror; }@@ -150,20 +132,22 @@ no version information available (required by ", name, ")"); if (verbose) { /* XXX We cannot translate the message. */- errstring = make_string ("weak version `", string,- "' not found (required by ", name, ")");+ _dl_exception_create_format+ (&exception, DSO_FILENAME (map->l_name),+ "weak version `%s' not found (required by %s)", string, name); goto call_cerror; } return 0; } /* XXX We cannot translate the message. */- errstring = make_string ("version `", string, "' not found (required by ",- name, ")");+ _dl_exception_create_format+ (&exception, DSO_FILENAME (map->l_name),+ "version `%s' not found (required by %s)", string, name); result = 1; call_cerror:- _dl_signal_cerror (0, DSO_FILENAME (map->l_name),- N_("version lookup error"), errstring);+ _dl_signal_cexception (0, &exception, N_("version lookup error"));+ _dl_exception_free (&exception); return result; } @@ -181,8 +165,8 @@ _dl_check_map_versions (struct link_map *map, int verbose, int trace_mode) /* We need to find out which is the highest version index used in a dependecy. */ unsigned int ndx_high = 0;+ struct dl_exception exception; /* Initialize to make the compiler happy. */- const char *errstring = NULL; int errval = 0; /* If we don't have a string table, we must be ok. */@@ -205,13 +189,12 @@ _dl_check_map_versions (struct link_map *map, int verbose, int trace_mode) char buf[20]; buf[sizeof (buf) - 1] = '\0'; /* XXX We cannot translate the message. */- errstring = make_string ("unsupported version ",- _itoa (ent->vn_version,- &buf[sizeof (buf) - 1], 10, 0),- " of Verneed record\n");+ _dl_exception_create_format+ (&exception, DSO_FILENAME (map->l_name),+ "unsupported version %s of Verneed record",+ _itoa (ent->vn_version, &buf[sizeof (buf) - 1], 10, 0)); call_error:- _dl_signal_error (errval, DSO_FILENAME (map->l_name),- NULL, errstring);+ _dl_signal_exception (errval, &exception, NULL); } while (1)@@ -293,7 +276,9 @@ _dl_check_map_versions (struct link_map *map, int verbose, int trace_mode) calloc (ndx_high + 1, sizeof (*map->l_versions)); if (__glibc_unlikely (map->l_versions == NULL)) {- errstring = N_("cannot allocate version reference table");+ _dl_exception_create+ (&exception, DSO_FILENAME (map->l_name),+ N_("cannot allocate version reference table")); errval = ENOMEM; goto call_error; }diff --git a/sysdeps/generic/ldsodefs.h b/sysdeps/generic/ldsodefs.hindex 4508365871..1c0b9cb32e 100644--- a/sysdeps/generic/ldsodefs.h+++ b/sysdeps/generic/ldsodefs.h@@ -732,31 +732,88 @@ _dl_dprintf (int fd, const char *fmt, ...) while (1) -/* This function is called by all the internal dynamic linker functions- when they encounter an error. ERRCODE is either an `errno' code or- zero; OBJECT is the name of the problematical shared object, or null if- it is a general problem; ERRSTRING is a string describing the specific- problem. */+/* An exception raised by the _dl_signal_error function family and+ caught by _dl_catch_error function family. Exceptions themselves+ are copied as part of the raise operation, but the strings are+ not. */+struct dl_exception+{+ const char *objname;+ const char *errstring;++ /* This buffer typically stores both objname and errstring+ above. */+ char *message_buffer;+};++/* Creates a new exception. This calls malloc; if allocation fails,+ dummy values are inserted. OBJECT is the name of the problematical+ shared object, or null if its a general problem. ERRSTRING is a+ string describing the specific problem. */+void _dl_exception_create (struct dl_exception *, const char *object,+ const char *errstring)+ __attribute__ ((nonnull (1, 3)));+rtld_hidden_proto (_dl_exception_create)++/* Like _dl_exception_create, but create errstring from a format+ string FMT. Currently, only "%s" and "%%" are supported as format+ directives. */+void _dl_exception_create_format (struct dl_exception *, const char *objname,+ const char *fmt, ...)+ __attribute__ ((nonnull (1, 3), format (printf, 3, 4)));+rtld_hidden_proto (_dl_exception_create_format)++/* Deallocate the exception, freeing allocated buffers (if+ possible). */+void _dl_exception_free (struct dl_exception *)+ __attribute__ ((nonnull (1)));+rtld_hidden_proto (_dl_exception_free)++/* This function is called by all the internal dynamic linker+ functions when they encounter an error. ERRCODE is either an+ `errno' code or zero; it specifies the return value of+ _dl_catch_error. OCCASION is included in the error message if the+ process is terminated immediately. */+void _dl_signal_exception (int errcode, struct dl_exception *,+ const char *occasion)+ __attribute__ ((__noreturn__));+libc_hidden_proto (_dl_signal_exception)++/* Like _dl_signal_exception, but creates the exception first. */ extern void _dl_signal_error (int errcode, const char *object,- const char *occurred, const char *errstring)+ const char *occasion, const char *errstring) internal_function __attribute__ ((__noreturn__)); libc_hidden_proto (_dl_signal_error) -/* Like _dl_signal_error, but may return when called in the context of- _dl_receive_error. This is only used during ld.so bootstrap. In- static and profiled builds, this is equivalent to- _dl_signal_error. */+/* Like _dl_signal_exception, but may return when called in the+ context of _dl_receive_error. This is only used during ld.so+ bootstrap. In static and profiled builds, this is equivalent to+ _dl_signal_exception. */+#if IS_IN (rtld)+extern void _dl_signal_cexception (int errcode, struct dl_exception *,+ const char *occasion) attribute_hidden;+#else+__attribute__ ((always_inline))+static inline void+_dl_signal_cexception (int errcode, struct dl_exception *exception,+ const char *occasion)+{+ _dl_signal_exception (errcode, exception, occasion);+}+#endif++/* See _dl_signal_cexception above. */ #if IS_IN (rtld) extern void _dl_signal_cerror (int errcode, const char *object,- const char *occation, const char *errstring)+ const char *occasion, const char *errstring) internal_function attribute_hidden; #else __attribute__ ((always_inline)) static inline void _dl_signal_cerror (int errcode, const char *object,- const char *occation, const char *errstring)+ const char *occasion, const char *errstring) {- _dl_signal_error (errcode, object, occation, errstring);+ _dl_signal_error (errcode, object, occasion, errstring); } #endif @@ -768,20 +825,28 @@ extern void _dl_receive_error (receiver_fct fct, void (*operate) (void *), void *args) internal_function attribute_hidden; -/* Call OPERATE, catching errors from `dl_signal_error'. If there is no- error, *ERRSTRING is set to null. If there is an error, *ERRSTRING is- set to a string constructed from the strings passed to _dl_signal_error,- and the error code passed is the return value and *OBJNAME is set to- the object name which experienced the problems. ERRSTRING if nonzero- points to a malloc'ed string which the caller has to free after use.- ARGS is passed as argument to OPERATE. MALLOCEDP is set to true only- if the returned string is allocated using the libc's malloc. */+/* Call OPERATE, catching errors from `_dl_signal_error' and related+ functions. If there is no error, *ERRSTRING is set to null. If+ there is an error, *ERRSTRING is set to a string constructed from+ the strings passed to _dl_signal_error, and the error code passed+ is the return value and *OBJNAME is set to the object name which+ experienced the problems. ERRSTRING if nonzero points to a+ malloc'ed string which the caller has to free after use. ARGS is+ passed as argument to OPERATE. MALLOCEDP is set to true only if+ the returned string is allocated using the libc's malloc. */ extern int _dl_catch_error (const char **objname, const char **errstring, bool *mallocedp, void (*operate) (void *), void *args) internal_function; libc_hidden_proto (_dl_catch_error) +/* Call OPERATE (ARGS). If no error occurs, set *EXCEPTION to zero.+ Otherwise, store a copy of the raised exception in *EXCEPTION,+ which has to be freed by _dl_exception_free. */+int _dl_catch_exception (struct dl_exception *exception,+ void (*operate) (void *), void *args);+libc_hidden_proto (_dl_catch_exception)+ /* Open the shared object NAME and map in its segments. LOADER's DT_RPATH is used in searching for NAME. If the object is already opened, returns its existing map. */diff --git a/sysdeps/generic/localplt.data b/sysdeps/generic/localplt.dataindex 81c741b038..2d5c66ae28 100644--- a/sysdeps/generic/localplt.data+++ b/sysdeps/generic/localplt.data@@ -16,3 +16,5 @@ ld.so: free # The TLS-enabled version of these functions is interposed from libc.so. ld.so: _dl_signal_error ld.so: _dl_catch_error+ld.so: _dl_signal_exception+ld.so: _dl_catch_exceptiondiff --git a/sysdeps/unix/sysv/linux/aarch64/localplt.data b/sysdeps/unix/sysv/linux/aarch64/localplt.dataindex bb18ff9bb2..a60053b914 100644--- a/sysdeps/unix/sysv/linux/aarch64/localplt.data+++ b/sysdeps/unix/sysv/linux/aarch64/localplt.data@@ -18,3 +18,5 @@ ld.so: free # The TLS-enabled version of these functions is interposed from libc.so. ld.so: _dl_signal_error ld.so: _dl_catch_error+ld.so: _dl_signal_exception+ld.so: _dl_catch_exceptiondiff --git a/sysdeps/unix/sysv/linux/alpha/localplt.data b/sysdeps/unix/sysv/linux/alpha/localplt.dataindex 1f0e3b494e..c69eb04ce5 100644--- a/sysdeps/unix/sysv/linux/alpha/localplt.data+++ b/sysdeps/unix/sysv/linux/alpha/localplt.data@@ -35,3 +35,5 @@ ld.so: free + RELA R_ALPHA_GLOB_DAT # The TLS-enabled version of these functions is interposed from libc.so. ld.so: _dl_signal_error + RELA R_ALPHA_GLOB_DAT ld.so: _dl_catch_error + RELA R_ALPHA_GLOB_DAT+ld.so: _dl_signal_exception + RELA R_ALPHA_GLOB_DAT+ld.so: _dl_catch_exception + RELA R_ALPHA_GLOB_DATdiff --git a/sysdeps/unix/sysv/linux/arm/localplt.data b/sysdeps/unix/sysv/linux/arm/localplt.dataindex 19d3299d98..7bd541c28a 100644--- a/sysdeps/unix/sysv/linux/arm/localplt.data+++ b/sysdeps/unix/sysv/linux/arm/localplt.data@@ -17,3 +17,5 @@ ld.so: free # The TLS-enabled version of these functions is interposed from libc.so. ld.so: _dl_signal_error ld.so: _dl_catch_error+ld.so: _dl_signal_exception+ld.so: _dl_catch_exceptiondiff --git a/sysdeps/unix/sysv/linux/hppa/localplt.data b/sysdeps/unix/sysv/linux/hppa/localplt.dataindex db9e24b090..3279c0af05 100644--- a/sysdeps/unix/sysv/linux/hppa/localplt.data+++ b/sysdeps/unix/sysv/linux/hppa/localplt.data@@ -21,3 +21,5 @@ ld.so: free # The TLS-enabled version of these functions is interposed from libc.so. ld.so: _dl_signal_error ld.so: _dl_catch_error+ld.so: _dl_signal_exception+ld.so: _dl_catch_exceptiondiff --git a/sysdeps/unix/sysv/linux/i386/localplt.data b/sysdeps/unix/sysv/linux/i386/localplt.dataindex 8ea4333846..f6f20a5d15 100644--- a/sysdeps/unix/sysv/linux/i386/localplt.data+++ b/sysdeps/unix/sysv/linux/i386/localplt.data@@ -16,3 +16,5 @@ ld.so: free + REL R_386_GLOB_DAT # The TLS-enabled version of these functions is interposed from libc.so. ld.so: _dl_signal_error + REL R_386_GLOB_DAT ld.so: _dl_catch_error + REL R_386_GLOB_DAT+ld.so: _dl_signal_exception + REL R_386_GLOB_DAT+ld.so: _dl_catch_exception + REL R_386_GLOB_DATdiff --git a/sysdeps/unix/sysv/linux/ia64/localplt.data b/sysdeps/unix/sysv/linux/ia64/localplt.dataindex fd2b98c8b6..3820e2a4e6 100644--- a/sysdeps/unix/sysv/linux/ia64/localplt.data+++ b/sysdeps/unix/sysv/linux/ia64/localplt.data@@ -15,3 +15,5 @@ ld.so: free # The TLS-enabled version of these functions is interposed from libc.so. ld.so: _dl_signal_error ld.so: _dl_catch_error+ld.so: _dl_signal_exception+ld.so: _dl_catch_exceptiondiff --git a/sysdeps/unix/sysv/linux/m68k/localplt.data b/sysdeps/unix/sysv/linux/m68k/localplt.dataindex 1a2acfdb93..c70d6ea301 100644--- a/sysdeps/unix/sysv/linux/m68k/localplt.data+++ b/sysdeps/unix/sysv/linux/m68k/localplt.data@@ -15,3 +15,5 @@ ld.so: free # The TLS-enabled version of these functions is interposed from libc.so. ld.so: _dl_signal_error ld.so: _dl_catch_error+ld.so: _dl_signal_exception+ld.so: _dl_catch_exceptiondiff --git a/sysdeps/unix/sysv/linux/microblaze/localplt.data b/sysdeps/unix/sysv/linux/microblaze/localplt.dataindex ca476bedd8..8ca23897df 100644--- a/sysdeps/unix/sysv/linux/microblaze/localplt.data+++ b/sysdeps/unix/sysv/linux/microblaze/localplt.data@@ -16,3 +16,5 @@ ld.so: free # The TLS-enabled version of these functions is interposed from libc.so. ld.so: _dl_signal_error ld.so: _dl_catch_error+ld.so: _dl_signal_exception+ld.so: _dl_catch_exceptiondiff --git a/sysdeps/unix/sysv/linux/nios2/localplt.data b/sysdeps/unix/sysv/linux/nios2/localplt.dataindex b0d6dcae55..4430a5891e 100644--- a/sysdeps/unix/sysv/linux/nios2/localplt.data+++ b/sysdeps/unix/sysv/linux/nios2/localplt.data@@ -36,3 +36,5 @@ ld.so: free # The TLS-enabled version of these functions is interposed from libc.so. ld.so: _dl_signal_error ld.so: _dl_catch_error+ld.so: _dl_signal_exception+ld.so: _dl_catch_exceptiondiff --git a/sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/localplt.data b/sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/localplt.dataindex 50006317c7..e822e0a480 100644--- a/sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/localplt.data+++ b/sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/localplt.data@@ -14,3 +14,5 @@ ld.so: free # The TLS-enabled version of these functions is interposed from libc.so. ld.so: _dl_signal_error ld.so: _dl_catch_error+ld.so: _dl_signal_exception+ld.so: _dl_catch_exceptiondiff --git a/sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/localplt.data b/sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/localplt.dataindex 1c20d2f2b4..fead931d4e 100644--- a/sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/localplt.data+++ b/sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/localplt.data@@ -44,3 +44,5 @@ ld.so: free # The TLS-enabled version of these functions is interposed from libc.so. ld.so: _dl_signal_error ld.so: _dl_catch_error+ld.so: _dl_signal_exception+ld.so: _dl_catch_exceptiondiff --git a/sysdeps/unix/sysv/linux/powerpc/powerpc64/localplt.data b/sysdeps/unix/sysv/linux/powerpc/powerpc64/localplt.dataindex 6f8ed25922..c1209336d2 100644--- a/sysdeps/unix/sysv/linux/powerpc/powerpc64/localplt.data+++ b/sysdeps/unix/sysv/linux/powerpc/powerpc64/localplt.data@@ -13,3 +13,5 @@ ld.so: free # The TLS-enabled version of these functions is interposed from libc.so. ld.so: _dl_signal_error ld.so: _dl_catch_error+ld.so: _dl_signal_exception+ld.so: _dl_catch_exceptiondiff --git a/sysdeps/unix/sysv/linux/s390/localplt.data b/sysdeps/unix/sysv/linux/s390/localplt.dataindex 50006317c7..e822e0a480 100644--- a/sysdeps/unix/sysv/linux/s390/localplt.data+++ b/sysdeps/unix/sysv/linux/s390/localplt.data@@ -14,3 +14,5 @@ ld.so: free # The TLS-enabled version of these functions is interposed from libc.so. ld.so: _dl_signal_error ld.so: _dl_catch_error+ld.so: _dl_signal_exception+ld.so: _dl_catch_exceptiondiff --git a/sysdeps/unix/sysv/linux/sh/localplt.data b/sysdeps/unix/sysv/linux/sh/localplt.dataindex f1f5effc24..2753547d97 100644--- a/sysdeps/unix/sysv/linux/sh/localplt.data+++ b/sysdeps/unix/sysv/linux/sh/localplt.data@@ -19,3 +19,5 @@ ld.so: free # The TLS-enabled version of these functions is interposed from libc.so. ld.so: _dl_signal_error ld.so: _dl_catch_error+ld.so: _dl_signal_exception+ld.so: _dl_catch_exceptiondiff --git a/sysdeps/unix/sysv/linux/sparc/sparc32/localplt.data b/sysdeps/unix/sysv/linux/sparc/sparc32/localplt.dataindex 2f6ff3c3a6..1668f4017e 100644--- a/sysdeps/unix/sysv/linux/sparc/sparc32/localplt.data+++ b/sysdeps/unix/sysv/linux/sparc/sparc32/localplt.data@@ -26,3 +26,5 @@ ld.so: free # The TLS-enabled version of these functions is interposed from libc.so. ld.so: _dl_signal_error ld.so: _dl_catch_error+ld.so: _dl_signal_exception+ld.so: _dl_catch_exceptiondiff --git a/sysdeps/unix/sysv/linux/sparc/sparc64/localplt.data b/sysdeps/unix/sysv/linux/sparc/sparc64/localplt.dataindex 912bd1a16e..b881b9096d 100644--- a/sysdeps/unix/sysv/linux/sparc/sparc64/localplt.data+++ b/sysdeps/unix/sysv/linux/sparc/sparc64/localplt.data@@ -27,3 +27,5 @@ ld.so: free # The TLS-enabled version of these functions is interposed from libc.so. ld.so: _dl_signal_error ld.so: _dl_catch_error+ld.so: _dl_signal_exception+ld.so: _dl_catch_exceptiondiff --git a/sysdeps/x86_64/localplt.data b/sysdeps/x86_64/localplt.dataindex a1840cff31..c27a02b66a 100644--- a/sysdeps/x86_64/localplt.data+++ b/sysdeps/x86_64/localplt.data@@ -18,3 +18,5 @@ ld.so: free + RELA R_X86_64_GLOB_DAT # The TLS-enabled version of these functions is interposed from libc.so. ld.so: _dl_signal_error + RELA R_X86_64_GLOB_DAT ld.so: _dl_catch_error + RELA R_X86_64_GLOB_DAT+ld.so: _dl_signal_exception + RELA R_X86_64_GLOB_DAT+ld.so: _dl_catch_exception + RELA R_X86_64_GLOB_DAT
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