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author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 |
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committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /arch/um/kernel/helper.c | |
download | linux-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.tar.gz linux-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.tar.bz2 linux-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.zip |
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'arch/um/kernel/helper.c')
-rw-r--r-- | arch/um/kernel/helper.c | 173 |
1 files changed, 173 insertions, 0 deletions
diff --git a/arch/um/kernel/helper.c b/arch/um/kernel/helper.c new file mode 100644 index 000000000000..13b1f5c2f7ee --- /dev/null +++ b/arch/um/kernel/helper.c @@ -0,0 +1,173 @@ +/* + * Copyright (C) 2002 Jeff Dike (jdike@karaya.com) + * Licensed under the GPL + */ + +#include <stdio.h> +#include <stdlib.h> +#include <unistd.h> +#include <errno.h> +#include <sched.h> +#include <sys/signal.h> +#include <sys/wait.h> +#include "user.h" +#include "kern_util.h" +#include "user_util.h" +#include "os.h" + +struct helper_data { + void (*pre_exec)(void*); + void *pre_data; + char **argv; + int fd; +}; + +/* Debugging aid, changed only from gdb */ +int helper_pause = 0; + +static void helper_hup(int sig) +{ +} + +static int helper_child(void *arg) +{ + struct helper_data *data = arg; + char **argv = data->argv; + int errval; + + if(helper_pause){ + signal(SIGHUP, helper_hup); + pause(); + } + if(data->pre_exec != NULL) + (*data->pre_exec)(data->pre_data); + execvp(argv[0], argv); + errval = errno; + printk("execvp of '%s' failed - errno = %d\n", argv[0], errno); + os_write_file(data->fd, &errval, sizeof(errval)); + os_kill_process(os_getpid(), 0); + return(0); +} + +/* Returns either the pid of the child process we run or -E* on failure. + * XXX The alloc_stack here breaks if this is called in the tracing thread */ +int run_helper(void (*pre_exec)(void *), void *pre_data, char **argv, + unsigned long *stack_out) +{ + struct helper_data data; + unsigned long stack, sp; + int pid, fds[2], ret, n; + + if((stack_out != NULL) && (*stack_out != 0)) + stack = *stack_out; + else stack = alloc_stack(0, um_in_interrupt()); + if(stack == 0) + return(-ENOMEM); + + ret = os_pipe(fds, 1, 0); + if(ret < 0){ + printk("run_helper : pipe failed, ret = %d\n", -ret); + goto out_free; + } + + ret = os_set_exec_close(fds[1], 1); + if(ret < 0){ + printk("run_helper : setting FD_CLOEXEC failed, ret = %d\n", + -ret); + goto out_close; + } + + sp = stack + page_size() - sizeof(void *); + data.pre_exec = pre_exec; + data.pre_data = pre_data; + data.argv = argv; + data.fd = fds[1]; + pid = clone(helper_child, (void *) sp, CLONE_VM | SIGCHLD, &data); + if(pid < 0){ + printk("run_helper : clone failed, errno = %d\n", errno); + ret = -errno; + goto out_close; + } + + os_close_file(fds[1]); + fds[1] = -1; + + /*Read the errno value from the child.*/ + n = os_read_file(fds[0], &ret, sizeof(ret)); + if(n < 0){ + printk("run_helper : read on pipe failed, ret = %d\n", -n); + ret = n; + os_kill_process(pid, 1); + } + else if(n != 0){ + CATCH_EINTR(n = waitpid(pid, NULL, 0)); + ret = -errno; + } else { + ret = pid; + } + +out_close: + if (fds[1] != -1) + os_close_file(fds[1]); + os_close_file(fds[0]); +out_free: + if(stack_out == NULL) + free_stack(stack, 0); + else *stack_out = stack; + return(ret); +} + +int run_helper_thread(int (*proc)(void *), void *arg, unsigned int flags, + unsigned long *stack_out, int stack_order) +{ + unsigned long stack, sp; + int pid, status; + + stack = alloc_stack(stack_order, um_in_interrupt()); + if(stack == 0) return(-ENOMEM); + + sp = stack + (page_size() << stack_order) - sizeof(void *); + pid = clone(proc, (void *) sp, flags | SIGCHLD, arg); + if(pid < 0){ + printk("run_helper_thread : clone failed, errno = %d\n", + errno); + return(-errno); + } + if(stack_out == NULL){ + CATCH_EINTR(pid = waitpid(pid, &status, 0)); + if(pid < 0){ + printk("run_helper_thread - wait failed, errno = %d\n", + errno); + pid = -errno; + } + if(!WIFEXITED(status) || (WEXITSTATUS(status) != 0)) + printk("run_helper_thread - thread returned status " + "0x%x\n", status); + free_stack(stack, stack_order); + } + else *stack_out = stack; + return(pid); +} + +int helper_wait(int pid, int block) +{ + int ret; + + CATCH_EINTR(ret = waitpid(pid, NULL, WNOHANG)); + if(ret < 0){ + printk("helper_wait : waitpid failed, errno = %d\n", errno); + return(-errno); + } + return(ret); +} + +/* + * Overrides for Emacs so that we follow Linus's tabbing style. + * Emacs will notice this stuff at the end of the file and automatically + * adjust the settings for this buffer only. This must remain at the end + * of the file. + * --------------------------------------------------------------------------- + * Local variables: + * c-file-style: "linux" + * End: + */ |