diff options
Diffstat (limited to 'exec')
| -rw-r--r-- | exec/exec.c | 60 |
1 files changed, 33 insertions, 27 deletions
diff --git a/exec/exec.c b/exec/exec.c index e267c70d..607faeea 100644 --- a/exec/exec.c +++ b/exec/exec.c @@ -108,6 +108,37 @@ check_section (bfd *bfd, asection *sec, void *userdata) #endif +/* Zero the specified region but don't crash the server if it faults. */ + +static error_t +safe_bzero (void *ptr, size_t size) +{ + jmp_buf env; + void fault (int signo) { longjmp (env, 1); } + thread_t thisthread = hurd_thread_self (); + volatile error_t error; + sighandler_t preempt (thread_t thread, int signo, + long int sigcode, int sigerror) + { + if (thread == thisthread) + { + error = sigerror ?: EIO; + return &fault; + } + return SIG_DFL; + } + struct hurd_signal_preempt preempter; + hurd_preempt_signals (&preempter, SIGSEGV, + (long int) ptr, (long int) (ptr + size), + &preempt); + error = 0; + if (! setjmp (env)) + bzero (ptr, size); + hurd_unpreempt_signals (&preempter, SIGSEGV); + return error; +} + + /* Load or allocate a section. */ static void load_section (void *section, struct execdata *u) @@ -392,33 +423,8 @@ load_section (void *section, struct execdata *u) vm_deallocate (u->task, mapstart, memsz); return; } - { - /* Zero the appropriate portion of our copy of the page. All - this rigamorole is in case the memory backing this page is - bogus and we fault in bzero; we want to return the fault's - error code to the user, rather than crash the server. */ - jmp_buf env; - void fault (int signo) { longjmp (env, 1); } - thread_t thisthread = hurd_thread_self (); - sighandler_t preempt (thread_t thread, int signo, - long int sigcode, int sigerror) - { - if (thread == thisthread) - { - u->error = sigerror ?: EIO; - return &fault; - } - return SIG_DFL; - } - struct hurd_signal_preempt preempter; - hurd_preempt_signals (&preempter, SIGSEGV, - ourpage, ourpage + vm_page_size, - &preempt); - if (! setjmp (env)) - bzero ((void *) (ourpage + (addr - overlap_page)), - size - (addr - overlap_page)); - hurd_unpreempt_signals (&preempter, SIGSEGV); - } + u->error = safe_bzero ((void *) (ourpage + (addr - overlap_page)), + size - (addr - overlap_page)); if (! u->error && !(vm_prot & VM_PROT_WRITE)) u->error = vm_protect (u->task, overlap_page, size, 0, VM_PROT_WRITE); |