diff options
| -rw-r--r-- | arch/um/kernel/process.c | 48 |
1 files changed, 19 insertions, 29 deletions
diff --git a/arch/um/kernel/process.c b/arch/um/kernel/process.c index 793c77c6ef9..1b5ef3e96c7 100644 --- a/arch/um/kernel/process.c +++ b/arch/um/kernel/process.c @@ -130,7 +130,7 @@ int start_fork_tramp(void *thread_arg, unsigned long temp_stack, return(arg.pid); } -static int ptrace_child(void *arg) +static int ptrace_child(void) { int ret; int pid = os_getpid(), ppid = getppid(); @@ -159,20 +159,16 @@ static int ptrace_child(void *arg) _exit(ret); } -static int start_ptraced_child(void **stack_out) +static int start_ptraced_child(void) { - void *stack; - unsigned long sp; int pid, n, status; - stack = mmap(NULL, PAGE_SIZE, PROT_READ | PROT_WRITE | PROT_EXEC, - MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); - if(stack == MAP_FAILED) - panic("check_ptrace : mmap failed, errno = %d", errno); - sp = (unsigned long) stack + PAGE_SIZE - sizeof(void *); - pid = clone(ptrace_child, (void *) sp, SIGCHLD, NULL); + pid = fork(); + if(pid == 0) + ptrace_child(); + if(pid < 0) - panic("check_ptrace : clone failed, errno = %d", errno); + panic("check_ptrace : fork failed, errno = %d", errno); CATCH_EINTR(n = waitpid(pid, &status, WUNTRACED)); if(n < 0) panic("check_ptrace : wait failed, errno = %d", errno); @@ -180,7 +176,6 @@ static int start_ptraced_child(void **stack_out) panic("check_ptrace : expected SIGSTOP, got status = %d", status); - *stack_out = stack; return(pid); } @@ -188,12 +183,12 @@ static int start_ptraced_child(void **stack_out) * just avoid using sysemu, not panic, but only if SYSEMU features are broken. * So only for SYSEMU features we test mustpanic, while normal host features * must work anyway!*/ -static int stop_ptraced_child(int pid, void *stack, int exitcode, int mustpanic) +static int stop_ptraced_child(int pid, int exitcode, int mustexit) { int status, n, ret = 0; if(ptrace(PTRACE_CONT, pid, 0, 0) < 0) - panic("check_ptrace : ptrace failed, errno = %d", errno); + panic("stop_ptraced_child : ptrace failed, errno = %d", errno); CATCH_EINTR(n = waitpid(pid, &status, 0)); if(!WIFEXITED(status) || (WEXITSTATUS(status) != exitcode)) { int exit_with = WEXITSTATUS(status); @@ -204,15 +199,13 @@ static int stop_ptraced_child(int pid, void *stack, int exitcode, int mustpanic) printk("check_ptrace : child exited with exitcode %d, while " "expecting %d; status 0x%x", exit_with, exitcode, status); - if (mustpanic) + if (mustexit) panic("\n"); else printk("\n"); ret = -1; } - if(munmap(stack, PAGE_SIZE) < 0) - panic("check_ptrace : munmap failed, errno = %d", errno); return ret; } @@ -234,12 +227,11 @@ __uml_setup("nosysemu", nosysemu_cmd_param, static void __init check_sysemu(void) { - void *stack; int pid, syscall, n, status, count=0; printk("Checking syscall emulation patch for ptrace..."); sysemu_supported = 0; - pid = start_ptraced_child(&stack); + pid = start_ptraced_child(); if(ptrace(PTRACE_SYSEMU, pid, 0, 0) < 0) goto fail; @@ -257,7 +249,7 @@ static void __init check_sysemu(void) panic("check_sysemu : failed to modify system " "call return, errno = %d", errno); - if (stop_ptraced_child(pid, stack, 0, 0) < 0) + if (stop_ptraced_child(pid, 0, 0) < 0) goto fail_stopped; sysemu_supported = 1; @@ -265,7 +257,7 @@ static void __init check_sysemu(void) set_using_sysemu(!force_sysemu_disabled); printk("Checking advanced syscall emulation patch for ptrace..."); - pid = start_ptraced_child(&stack); + pid = start_ptraced_child(); while(1){ count++; if(ptrace(PTRACE_SYSEMU_SINGLESTEP, pid, 0, 0) < 0) @@ -290,7 +282,7 @@ static void __init check_sysemu(void) break; } } - if (stop_ptraced_child(pid, stack, 0, 0) < 0) + if (stop_ptraced_child(pid, 0, 0) < 0) goto fail_stopped; sysemu_supported = 2; @@ -301,18 +293,17 @@ static void __init check_sysemu(void) return; fail: - stop_ptraced_child(pid, stack, 1, 0); + stop_ptraced_child(pid, 1, 0); fail_stopped: printk("missing\n"); } void __init check_ptrace(void) { - void *stack; int pid, syscall, n, status; printk("Checking that ptrace can change system call numbers..."); - pid = start_ptraced_child(&stack); + pid = start_ptraced_child(); if (ptrace(PTRACE_OLDSETOPTIONS, pid, 0, (void *)PTRACE_O_TRACESYSGOOD) < 0) panic("check_ptrace: PTRACE_SETOPTIONS failed, errno = %d", errno); @@ -339,7 +330,7 @@ void __init check_ptrace(void) break; } } - stop_ptraced_child(pid, stack, 0, 1); + stop_ptraced_child(pid, 0, 1); printk("OK\n"); check_sysemu(); } @@ -371,11 +362,10 @@ void forward_pending_sigio(int target) static inline int check_skas3_ptrace_support(void) { struct ptrace_faultinfo fi; - void *stack; int pid, n, ret = 1; printf("Checking for the skas3 patch in the host..."); - pid = start_ptraced_child(&stack); + pid = start_ptraced_child(); n = ptrace(PTRACE_FAULTINFO, pid, 0, &fi); if (n < 0) { @@ -390,7 +380,7 @@ static inline int check_skas3_ptrace_support(void) } init_registers(pid); - stop_ptraced_child(pid, stack, 1, 1); + stop_ptraced_child(pid, 1, 1); return(ret); } |