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| author | Florian Weimer <fweimer@redhat.com> | 2020-12-16 15:09:52 +0100 |
|---|---|---|
| committer | Florian Weimer <fweimer@redhat.com> | 2020-12-16 15:13:40 +0100 |
| commit | e7570f4131a6af9405af7b4fd1c31de807e7cf68 (patch) | |
| tree | 0f11050a7a1b768fb0d683dc60412bc2a101c3a5 /elf | |
| parent | 9459fe9da0f981f77ba931790f82e43ac552b73c (diff) | |
| download | glibc-e7570f4131a6af9405af7b4fd1c31de807e7cf68.tar glibc-e7570f4131a6af9405af7b4fd1c31de807e7cf68.tar.gz glibc-e7570f4131a6af9405af7b4fd1c31de807e7cf68.tar.bz2 glibc-e7570f4131a6af9405af7b4fd1c31de807e7cf68.zip | |
Replace __libc_multiple_libcs with __libc_initial flag
Change sbrk to fail for !__libc_initial (in the generic
implementation). As a result, sbrk is (relatively) safe to use
for the __libc_initial case (from the main libc). It is therefore
no longer necessary to avoid using it in that case (or updating the
brk cache), and the __libc_initial flag does not need to be updated
as part of dlmopen or static dlopen.
As before, direct brk system calls on Linux may lead to memory
corruption.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Diffstat (limited to 'elf')
| -rw-r--r-- | elf/dl-open.c | 6 | ||||
| -rw-r--r-- | elf/dl-sysdep.c | 2 | ||||
| -rw-r--r-- | elf/libc_early_init.c | 9 |
3 files changed, 9 insertions, 8 deletions
diff --git a/elf/dl-open.c b/elf/dl-open.c index 8769e47051..6710ea04cd 100644 --- a/elf/dl-open.c +++ b/elf/dl-open.c @@ -787,12 +787,6 @@ dl_open_worker (void *a) if (mode & RTLD_GLOBAL) add_to_global_update (new); -#ifndef SHARED - /* We must be the static _dl_open in libc.a. A static program that - has loaded a dynamic object now has competition. */ - __libc_multiple_libcs = 1; -#endif - /* Let the user know about the opencount. */ if (__glibc_unlikely (GLRO(dl_debug_mask) & DL_DEBUG_FILES)) _dl_debug_printf ("opening file=%s [%lu]; direct_opencount=%u\n\n", diff --git a/elf/dl-sysdep.c b/elf/dl-sysdep.c index 854570821c..6cc4a76560 100644 --- a/elf/dl-sysdep.c +++ b/elf/dl-sysdep.c @@ -58,8 +58,6 @@ ElfW(Addr) _dl_base_addr; #endif int __libc_enable_secure attribute_relro = 0; rtld_hidden_data_def (__libc_enable_secure) -int __libc_multiple_libcs = 0; /* Defining this here avoids the inclusion - of init-first. */ /* This variable contains the lowest stack address ever used. */ void *__libc_stack_end attribute_relro = NULL; rtld_hidden_data_def(__libc_stack_end) diff --git a/elf/libc_early_init.c b/elf/libc_early_init.c index 725ab2f811..28c6adca10 100644 --- a/elf/libc_early_init.c +++ b/elf/libc_early_init.c @@ -18,8 +18,13 @@ #include <ctype.h> #include <libc-early-init.h> +#include <libc-internal.h> #include <sys/single_threaded.h> +#ifdef SHARED +_Bool __libc_initial; +#endif + void __libc_early_init (_Bool initial) { @@ -28,4 +33,8 @@ __libc_early_init (_Bool initial) /* Only the outer namespace is marked as single-threaded. */ __libc_single_threaded = initial; + +#ifdef SHARED + __libc_initial = initial; +#endif } |