diff options
Diffstat (limited to 'src/env/__libc_start_main.c')
| -rw-r--r-- | src/env/__libc_start_main.c | 25 |
1 files changed, 23 insertions, 2 deletions
diff --git a/src/env/__libc_start_main.c b/src/env/__libc_start_main.c index 58da9e83..c5b277bd 100644 --- a/src/env/__libc_start_main.c +++ b/src/env/__libc_start_main.c @@ -17,6 +17,9 @@ weak_alias(dummy1, __init_ssp); #define AUX_CNT 38 +#ifdef __GNUC__ +__attribute__((__noinline__)) +#endif void __init_libc(char **envp, char *pn) { size_t i, *auxv, aux[AUX_CNT] = { 0 }; @@ -25,7 +28,7 @@ void __init_libc(char **envp, char *pn) libc.auxv = auxv = (void *)(envp+i+1); for (i=0; auxv[i]; i+=2) if (auxv[i]<AUX_CNT) aux[auxv[i]] = auxv[i+1]; __hwcap = aux[AT_HWCAP]; - __sysinfo = aux[AT_SYSINFO]; + if (aux[AT_SYSINFO]) __sysinfo = aux[AT_SYSINFO]; libc.page_size = aux[AT_PAGESZ]; if (!pn) pn = (void*)aux[AT_EXECFN]; @@ -63,11 +66,29 @@ static void libc_start_init(void) weak_alias(libc_start_init, __libc_start_init); -int __libc_start_main(int (*main)(int,char **,char **), int argc, char **argv) +typedef int lsm2_fn(int (*)(int,char **,char **), int, char **); +static lsm2_fn libc_start_main_stage2; + +int __libc_start_main(int (*main)(int,char **,char **), int argc, char **argv, + void (*init_dummy)(), void(*fini_dummy)(), void(*ldso_dummy)()) { char **envp = argv+argc+1; + /* External linkage, and explicit noinline attribute if available, + * are used to prevent the stack frame used during init from + * persisting for the entire process lifetime. */ __init_libc(envp, argv[0]); + + /* Barrier against hoisting application code or anything using ssp + * or thread pointer prior to its initialization above. */ + lsm2_fn *stage2 = libc_start_main_stage2; + __asm__ ( "" : "+r"(stage2) : : "memory" ); + return stage2(main, argc, argv); +} + +static int libc_start_main_stage2(int (*main)(int,char **,char **), int argc, char **argv) +{ + char **envp = argv+argc+1; __libc_start_init(); /* Pass control to the application */ |