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author | kib <kib@FreeBSD.org> | 2011-01-08 17:13:43 +0000 |
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committer | kib <kib@FreeBSD.org> | 2011-01-08 17:13:43 +0000 |
commit | 6e23841922a5006f49524e7833864f5505466fa0 (patch) | |
tree | 2bd624efb926ca1e72001fb3dbd4e1c9b451136e | |
parent | 5cec74bed917b7e7fe4e854d8ee69bbc3a117817 (diff) | |
download | FreeBSD-src-6e23841922a5006f49524e7833864f5505466fa0.zip FreeBSD-src-6e23841922a5006f49524e7833864f5505466fa0.tar.gz |
Implement __pthread_map_stacks_exec() callback for libc, to change the
stack protection to allow execution for single-threaded processes.
-rw-r--r-- | lib/libc/gen/Symbol.map | 2 | ||||
-rw-r--r-- | lib/libc/gen/dlfcn.c | 10 | ||||
-rw-r--r-- | lib/libc/gen/elf_utils.c | 27 |
3 files changed, 39 insertions, 0 deletions
diff --git a/lib/libc/gen/Symbol.map b/lib/libc/gen/Symbol.map index f9abab5..32cf92c 100644 --- a/lib/libc/gen/Symbol.map +++ b/lib/libc/gen/Symbol.map @@ -453,6 +453,7 @@ FBSDprivate_1.0 { _rtld_atfork_pre; _rtld_atfork_post; _rtld_error; /* for private use */ + _rtld_get_stack_prot; _rtld_thread_init; /* for private use */ __elf_phdr_match_addr; _err; @@ -499,4 +500,5 @@ FBSDprivate_1.0 { _libc_sem_getvalue_compat; __elf_aux_vector; + __pthread_map_stacks_exec; }; diff --git a/lib/libc/gen/dlfcn.c b/lib/libc/gen/dlfcn.c index 930ebc1..b109cc9 100644 --- a/lib/libc/gen/dlfcn.c +++ b/lib/libc/gen/dlfcn.c @@ -30,6 +30,7 @@ __FBSDID("$FreeBSD$"); /* * Linkage to services provided by the dynamic linker. */ +#include <sys/mman.h> #include <dlfcn.h> #include <link.h> #include <stddef.h> @@ -165,3 +166,12 @@ _rtld_addr_phdr(const void *addr, struct dl_phdr_info *phdr_info) return (0); } + +#pragma weak _rtld_get_stack_prot +int +_rtld_get_stack_prot(void) +{ + + return (PROT_EXEC | PROT_READ | PROT_WRITE); +} + diff --git a/lib/libc/gen/elf_utils.c b/lib/libc/gen/elf_utils.c index 9ee5f41..7bd7511 100644 --- a/lib/libc/gen/elf_utils.c +++ b/lib/libc/gen/elf_utils.c @@ -26,7 +26,12 @@ * $FreeBSD$ */ +#include <sys/types.h> +#include <sys/mman.h> +#include <sys/resource.h> +#include <sys/sysctl.h> #include <link.h> +#include <stddef.h> int __elf_phdr_match_addr(struct dl_phdr_info *phdr_info, void *addr) @@ -45,3 +50,25 @@ __elf_phdr_match_addr(struct dl_phdr_info *phdr_info, void *addr) } return (i != phdr_info->dlpi_phnum); } + +#pragma weak __pthread_map_stacks_exec +void +__pthread_map_stacks_exec(void) +{ + int mib[2]; + struct rlimit rlim; + u_long usrstack; + size_t len; + + mib[0] = CTL_KERN; + mib[1] = KERN_USRSTACK; + len = sizeof(usrstack); + if (sysctl(mib, sizeof(mib) / sizeof(mib[0]), &usrstack, &len, NULL, 0) + == -1) + return; + if (getrlimit(RLIMIT_STACK, &rlim) == -1) + return; + mprotect((void *)(uintptr_t)(usrstack - rlim.rlim_cur), + rlim.rlim_cur, _rtld_get_stack_prot()); +} + |