diff options
author | Jeff Dike <jdike@addtoit.com> | 2005-11-07 09:58:51 +0100 |
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committer | Linus Torvalds <torvalds@g5.osdl.org> | 2005-11-07 16:53:31 +0100 |
commit | ff5c6ff54215fe284e515032878111de5d8a5ce1 (patch) | |
tree | ecf5e2eaacc9f45f5227b50d8bfaaf82e15b9647 /arch/um/os-Linux/helper.c | |
parent | [PATCH] uml: separate libc-dependent early initialization (diff) | |
download | linux-ff5c6ff54215fe284e515032878111de5d8a5ce1.tar.xz linux-ff5c6ff54215fe284e515032878111de5d8a5ce1.zip |
[PATCH] uml: separate libc-dependent helper code
The serial UML OS-abstraction layer patch (um/kernel dir).
This moves all systemcalls from helper.c file under os-Linux dir
Signed-off-by: Gennady Sharapov <Gennady.V.Sharapov@intel.com>
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Cc: Paolo Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'arch/um/os-Linux/helper.c')
-rw-r--r-- | arch/um/os-Linux/helper.c | 165 |
1 files changed, 165 insertions, 0 deletions
diff --git a/arch/um/os-Linux/helper.c b/arch/um/os-Linux/helper.c new file mode 100644 index 000000000000..36cc8475bcda --- /dev/null +++ b/arch/um/os-Linux/helper.c @@ -0,0 +1,165 @@ +/* + * 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)); + kill(os_getpid(), SIGKILL); + 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){ + ret = -errno; + printk("run_helper : clone failed, errno = %d\n", errno); + goto out_close; + } + + close(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; + kill(pid, SIGKILL); + CATCH_EINTR(waitpid(pid, NULL, 0)); + } + else if(n != 0){ + CATCH_EINTR(n = waitpid(pid, NULL, 0)); + ret = -errno; + } else { + ret = pid; + } + +out_close: + if (fds[1] != -1) + close(fds[1]); + close(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, err; + + 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){ + err = -errno; + printk("run_helper_thread : clone failed, errno = %d\n", + errno); + return err; + } + if(stack_out == NULL){ + CATCH_EINTR(pid = waitpid(pid, &status, 0)); + if(pid < 0){ + err = -errno; + printk("run_helper_thread - wait failed, errno = %d\n", + errno); + pid = err; + } + 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 ret; + + CATCH_EINTR(ret = waitpid(pid, NULL, WNOHANG)); + if(ret < 0){ + ret = -errno; + printk("helper_wait : waitpid failed, errno = %d\n", errno); + } + return(ret); +} |