commit 36fcdfbbc5463e55581fec67141df3493fb81f7e Author: Florian Weimer Date: Fri Jan 24 08:04:23 2025 +0100 Revert "stdlib: Support malloc-managed environ arrays for compatibility" This reverts commit b62759db04b8ed7f829c06f1d7c3b8fb70616493. Reason for revert: Incompatible with “env -i” and coreutils (bug 32588). Reviewed-by: H.J. Lu Conflicts: stdlib/Makefile (different test list) diff --git a/csu/init-first.c b/csu/init-first.c index b1ee92332f478429..316fed22706b1870 100644 --- a/csu/init-first.c +++ b/csu/init-first.c @@ -61,7 +61,6 @@ _init_first (int argc, char **argv, char **envp) __libc_argc = argc; __libc_argv = argv; __environ = envp; - __environ_startup = envp; #ifndef SHARED /* First the initialization which normally would be done by the diff --git a/csu/libc-start.c b/csu/libc-start.c index 4f1801c4af35a012..a2fc2f6f9665a48f 100644 --- a/csu/libc-start.c +++ b/csu/libc-start.c @@ -244,7 +244,6 @@ LIBC_START_MAIN (int (*main) (int, char **, char ** MAIN_AUXVEC_DECL), char **ev = &argv[argc + 1]; __environ = ev; - __environ_startup = ev; /* Store the lowest stack address. This is done in ld.so if this is the code for the DSO. */ diff --git a/include/unistd.h b/include/unistd.h index 781dbabde0aad494..5824485629793ccb 100644 --- a/include/unistd.h +++ b/include/unistd.h @@ -182,9 +182,6 @@ libc_hidden_proto (__sbrk) extern int __libc_enable_secure attribute_relro; rtld_hidden_proto (__libc_enable_secure) -/* Original value of __environ. Initialized by _init_first (dynamic) - or __libc_start_main (static). */ -extern char **__environ_startup attribute_hidden; /* Various internal function. */ extern void __libc_check_standard_fds (void) attribute_hidden; diff --git a/posix/environ.c b/posix/environ.c index 2430b47d8eee148c..a0ed0d80eab207f8 100644 --- a/posix/environ.c +++ b/posix/environ.c @@ -10,5 +10,3 @@ weak_alias (__environ, environ) /* The SVR4 ABI says `_environ' will be the name to use in case the user overrides the weak alias `environ'. */ weak_alias (__environ, _environ) - -char **__environ_startup; diff --git a/stdlib/Makefile b/stdlib/Makefile index 3f98e55763c75758..4cbf47d215353681 100644 --- a/stdlib/Makefile +++ b/stdlib/Makefile @@ -126,7 +126,6 @@ tests := \ tst-setcontext7 \ tst-setcontext8 \ tst-setcontext9 \ - tst-setenv-malloc \ tst-strfmon_l \ tst-strfrom \ tst-strfrom-locale \ diff --git a/stdlib/setenv.c b/stdlib/setenv.c index e02114103fc5957c..e3833bc514870bf4 100644 --- a/stdlib/setenv.c +++ b/stdlib/setenv.c @@ -191,52 +191,52 @@ __add_to_environ (const char *name, const char *value, const char *combined, ep[1] = NULL; else { - /* We cannot use __environ as is and need a larger allocation. */ - - if (start_environ == __environ_startup - || __environ_is_from_array_list (start_environ)) - { - /* Allocate a new array, managed in the list. */ - struct environ_array *target_array - = __environ_new_array (required_size); - if (target_array == NULL) - { - UNLOCK; - return -1; - } - result_environ = &target_array->array[0]; - - /* Copy over the __environ array contents. This code - handles the case start_environ == ep == NULL, too. */ - size_t i; - for (i = 0; start_environ + i < ep; ++i) - /* Regular store because unless there has been direct - manipulation of the environment, target_array is still - a private copy. */ - result_environ[i] = atomic_load_relaxed (start_environ + i); - } + /* We cannot use __environ as is and need to copy over the + __environ contents into an array managed via + __environ_array_list. */ + + struct environ_array *target_array; + if (__environ_array_list != NULL + && required_size <= __environ_array_list->allocated) + /* Existing array has enough room. Contents is copied below. */ + target_array = __environ_array_list; else { - /* Otherwise the application installed its own pointer. - Historically, this pointer was managed using realloc. - Continue doing so. This disables multi-threading - support. */ - result_environ = __libc_reallocarray (start_environ, - required_size, - sizeof (*result_environ)); - if (result_environ == NULL) + /* Allocate a new array. */ + target_array = __environ_new_array (required_size); + if (target_array == NULL) { UNLOCK; return -1; } } + /* Copy over the __environ array contents. This forward + copy slides backwards part of the array if __environ + points into target_array->array. This happens if an + application makes an assignment like: + + environ = &environ[1]; + + The forward copy avoids clobbering values that still + needing copying. This code handles the case + start_environ == ep == NULL, too. */ + size_t i; + for (i = 0; start_environ + i < ep; ++i) + /* Regular store because unless there has been direct + manipulation of the environment, target_array is still + a private copy. */ + target_array->array[i] = atomic_load_relaxed (start_environ + i); + /* This is the new place where we should add the element. */ - ep = result_environ + (required_size - 2); + ep = target_array->array + i; /* Add the null terminator in case there was a pointer there previously. */ ep[1] = NULL; + + /* And __environ should be repointed to our array. */ + result_environ = &target_array->array[0]; } } diff --git a/stdlib/tst-setenv-malloc.c b/stdlib/tst-setenv-malloc.c deleted file mode 100644 index 18a9d36842e67aa5..0000000000000000 --- a/stdlib/tst-setenv-malloc.c +++ /dev/null @@ -1,64 +0,0 @@ -/* Test using setenv with a malloc-allocated environ variable. - Copyright (C) 2025 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 - . */ - -/* This test is not in the scope for POSIX or any other standard, but - some applications assume that environ is a heap-allocated pointer - after a call to setenv on an empty environment. */ - -#include -#include -#include -#include - -static const char *original_path; -static char **save_environ; - -static void -rewrite_environ (void) -{ - save_environ = environ; - environ = xmalloc (sizeof (*environ)); - *environ = NULL; - TEST_COMPARE (setenv ("A", "1", 1), 0); - TEST_COMPARE (setenv ("B", "2", 1), 0); - TEST_VERIFY (environ != save_environ); - TEST_COMPARE_STRING (environ[0], "A=1"); - TEST_COMPARE_STRING (environ[1], "B=2"); - TEST_COMPARE_STRING (environ[2], NULL); - TEST_COMPARE_STRING (getenv ("PATH"), NULL); - free (environ); - environ = save_environ; - TEST_COMPARE_STRING (getenv ("PATH"), original_path); -} - -static int -do_test (void) -{ - original_path = getenv ("PATH"); - rewrite_environ (); - - /* Test again after reallocated the environment due to an initial - setenv call. */ - TEST_COMPARE (setenv ("TST_SETENV_MALLOC", "1", 1), 0); - TEST_VERIFY (environ != save_environ); - rewrite_environ (); - - return 0; -} - -#include