diff options
Diffstat (limited to 'arch/um/kernel/tt/ptproxy/proxy.c')
| -rw-r--r-- | arch/um/kernel/tt/ptproxy/proxy.c | 377 |
1 files changed, 377 insertions, 0 deletions
diff --git a/arch/um/kernel/tt/ptproxy/proxy.c b/arch/um/kernel/tt/ptproxy/proxy.c new file mode 100644 index 000000000000..58800c50b10e --- /dev/null +++ b/arch/um/kernel/tt/ptproxy/proxy.c @@ -0,0 +1,377 @@ +/********************************************************************** +proxy.c + +Copyright (C) 1999 Lars Brinkhoff. See the file COPYING for licensing +terms and conditions. + +Jeff Dike (jdike@karaya.com) : Modified for integration into uml +**********************************************************************/ + +/* XXX This file shouldn't refer to CONFIG_* */ + +#include <errno.h> +#include <stdio.h> +#include <stdlib.h> +#include <unistd.h> +#include <signal.h> +#include <string.h> +#include <termios.h> +#include <sys/wait.h> +#include <sys/types.h> +#include <sys/ioctl.h> +#include <asm/unistd.h> +#include "ptrace_user.h" + +#include "ptproxy.h" +#include "sysdep.h" +#include "wait.h" + +#include "user_util.h" +#include "user.h" +#include "os.h" +#include "tempfile.h" + +static int debugger_wait(debugger_state *debugger, int *status, int options, + int (*syscall)(debugger_state *debugger, pid_t child), + int (*normal_return)(debugger_state *debugger, + pid_t unused), + int (*wait_return)(debugger_state *debugger, + pid_t unused)) +{ + if(debugger->real_wait){ + debugger->handle_trace = normal_return; + syscall_continue(debugger->pid); + debugger->real_wait = 0; + return(1); + } + debugger->wait_status_ptr = status; + debugger->wait_options = options; + if((debugger->debugee != NULL) && debugger->debugee->event){ + syscall_continue(debugger->pid); + wait_for_stop(debugger->pid, SIGTRAP, PTRACE_SYSCALL, + NULL); + (*wait_return)(debugger, -1); + return(0); + } + else if(debugger->wait_options & WNOHANG){ + syscall_cancel(debugger->pid, 0); + debugger->handle_trace = syscall; + return(0); + } + else { + syscall_pause(debugger->pid); + debugger->handle_trace = wait_return; + debugger->waiting = 1; + } + return(1); +} + +/* + * Handle debugger trap, i.e. syscall. + */ + +int debugger_syscall(debugger_state *debugger, pid_t child) +{ + long arg1, arg2, arg3, arg4, arg5, result; + int syscall, ret = 0; + + syscall = get_syscall(debugger->pid, &arg1, &arg2, &arg3, &arg4, + &arg5); + + switch(syscall){ + case __NR_execve: + /* execve never returns */ + debugger->handle_trace = debugger_syscall; + break; + + case __NR_ptrace: + if(debugger->debugee->pid != 0) arg2 = debugger->debugee->pid; + if(!debugger->debugee->in_context) + child = debugger->debugee->pid; + result = proxy_ptrace(debugger, arg1, arg2, arg3, arg4, child, + &ret); + syscall_cancel(debugger->pid, result); + debugger->handle_trace = debugger_syscall; + return(ret); + +#ifdef __NR_waitpid + case __NR_waitpid: +#endif + case __NR_wait4: + if(!debugger_wait(debugger, (int *) arg2, arg3, + debugger_syscall, debugger_normal_return, + proxy_wait_return)) + return(0); + break; + + case __NR_kill: + if(!debugger->debugee->in_context) + child = debugger->debugee->pid; + if(arg1 == debugger->debugee->pid){ + result = kill(child, arg2); + syscall_cancel(debugger->pid, result); + debugger->handle_trace = debugger_syscall; + return(0); + } + else debugger->handle_trace = debugger_normal_return; + break; + + default: + debugger->handle_trace = debugger_normal_return; + } + + syscall_continue(debugger->pid); + return(0); +} + +/* Used by the tracing thread */ +static debugger_state parent; +static int parent_syscall(debugger_state *debugger, int pid); + +int init_parent_proxy(int pid) +{ + parent = ((debugger_state) { .pid = pid, + .wait_options = 0, + .wait_status_ptr = NULL, + .waiting = 0, + .real_wait = 0, + .expecting_child = 0, + .handle_trace = parent_syscall, + .debugee = NULL } ); + return(0); +} + +int parent_normal_return(debugger_state *debugger, pid_t unused) +{ + debugger->handle_trace = parent_syscall; + syscall_continue(debugger->pid); + return(0); +} + +static int parent_syscall(debugger_state *debugger, int pid) +{ + long arg1, arg2, arg3, arg4, arg5; + int syscall; + + syscall = get_syscall(pid, &arg1, &arg2, &arg3, &arg4, &arg5); + + if((syscall == __NR_wait4) +#ifdef __NR_waitpid + || (syscall == __NR_waitpid) +#endif + ){ + debugger_wait(&parent, (int *) arg2, arg3, parent_syscall, + parent_normal_return, parent_wait_return); + } + else ptrace(PTRACE_SYSCALL, pid, 0, 0); + return(0); +} + +int debugger_normal_return(debugger_state *debugger, pid_t unused) +{ + debugger->handle_trace = debugger_syscall; + syscall_continue(debugger->pid); + return(0); +} + +void debugger_cancelled_return(debugger_state *debugger, int result) +{ + debugger->handle_trace = debugger_syscall; + syscall_set_result(debugger->pid, result); + syscall_continue(debugger->pid); +} + +/* Used by the tracing thread */ +static debugger_state debugger; +static debugee_state debugee; + +void init_proxy (pid_t debugger_pid, int stopped, int status) +{ + debugger.pid = debugger_pid; + debugger.handle_trace = debugger_syscall; + debugger.debugee = &debugee; + debugger.waiting = 0; + debugger.real_wait = 0; + debugger.expecting_child = 0; + + debugee.pid = 0; + debugee.traced = 0; + debugee.stopped = stopped; + debugee.event = 0; + debugee.zombie = 0; + debugee.died = 0; + debugee.wait_status = status; + debugee.in_context = 1; +} + +int debugger_proxy(int status, int pid) +{ + int ret = 0, sig; + + if(WIFSTOPPED(status)){ + sig = WSTOPSIG(status); + if (sig == SIGTRAP) + ret = (*debugger.handle_trace)(&debugger, pid); + + else if(sig == SIGCHLD){ + if(debugger.expecting_child){ + ptrace(PTRACE_SYSCALL, debugger.pid, 0, sig); + debugger.expecting_child = 0; + } + else if(debugger.waiting) + real_wait_return(&debugger); + else { + ptrace(PTRACE_SYSCALL, debugger.pid, 0, sig); + debugger.real_wait = 1; + } + } + else ptrace(PTRACE_SYSCALL, debugger.pid, 0, sig); + } + else if(WIFEXITED(status)){ + tracer_panic("debugger (pid %d) exited with status %d", + debugger.pid, WEXITSTATUS(status)); + } + else if(WIFSIGNALED(status)){ + tracer_panic("debugger (pid %d) exited with signal %d", + debugger.pid, WTERMSIG(status)); + } + else { + tracer_panic("proxy got unknown status (0x%x) on debugger " + "(pid %d)", status, debugger.pid); + } + return(ret); +} + +void child_proxy(pid_t pid, int status) +{ + debugee.event = 1; + debugee.wait_status = status; + + if(WIFSTOPPED(status)){ + debugee.stopped = 1; + debugger.expecting_child = 1; + kill(debugger.pid, SIGCHLD); + } + else if(WIFEXITED(status) || WIFSIGNALED(status)){ + debugee.zombie = 1; + debugger.expecting_child = 1; + kill(debugger.pid, SIGCHLD); + } + else panic("proxy got unknown status (0x%x) on child (pid %d)", + status, pid); +} + +void debugger_parent_signal(int status, int pid) +{ + int sig; + + if(WIFSTOPPED(status)){ + sig = WSTOPSIG(status); + if(sig == SIGTRAP) (*parent.handle_trace)(&parent, pid); + else ptrace(PTRACE_SYSCALL, pid, 0, sig); + } +} + +void fake_child_exit(void) +{ + int status, pid; + + child_proxy(1, W_EXITCODE(0, 0)); + while(debugger.waiting == 1){ + CATCH_EINTR(pid = waitpid(debugger.pid, &status, WUNTRACED)); + if(pid != debugger.pid){ + printk("fake_child_exit - waitpid failed, " + "errno = %d\n", errno); + return; + } + debugger_proxy(status, debugger.pid); + } + CATCH_EINTR(pid = waitpid(debugger.pid, &status, WUNTRACED)); + if(pid != debugger.pid){ + printk("fake_child_exit - waitpid failed, " + "errno = %d\n", errno); + return; + } + if(ptrace(PTRACE_DETACH, debugger.pid, 0, SIGCONT) < 0) + printk("fake_child_exit - PTRACE_DETACH failed, errno = %d\n", + errno); +} + +char gdb_init_string[] = +"att 1 \n\ +b panic \n\ +b stop \n\ +handle SIGWINCH nostop noprint pass \n\ +"; + +int start_debugger(char *prog, int startup, int stop, int *fd_out) +{ + int slave, child; + + slave = open_gdb_chan(); + child = fork(); + if(child == 0){ + char *tempname = NULL; + int fd; + + if(setsid() < 0) perror("setsid"); + if((dup2(slave, 0) < 0) || (dup2(slave, 1) < 0) || + (dup2(slave, 2) < 0)){ + printk("start_debugger : dup2 failed, errno = %d\n", + errno); + exit(1); + } + if(ioctl(0, TIOCSCTTY, 0) < 0){ + printk("start_debugger : TIOCSCTTY failed, " + "errno = %d\n", errno); + exit(1); + } + if(tcsetpgrp (1, os_getpid()) < 0){ + printk("start_debugger : tcsetpgrp failed, " + "errno = %d\n", errno); +#ifdef notdef + exit(1); +#endif + } + fd = make_tempfile("/tmp/gdb_init-XXXXXX", &tempname, 0); + if(fd < 0){ + printk("start_debugger : make_tempfile failed," + "err = %d\n", -fd); + exit(1); + } + os_write_file(fd, gdb_init_string, sizeof(gdb_init_string) - 1); + if(startup){ + if(stop){ + os_write_file(fd, "b start_kernel\n", + strlen("b start_kernel\n")); + } + os_write_file(fd, "c\n", strlen("c\n")); + } + if(ptrace(PTRACE_TRACEME, 0, 0, 0) < 0){ + printk("start_debugger : PTRACE_TRACEME failed, " + "errno = %d\n", errno); + exit(1); + } + execlp("gdb", "gdb", "--command", tempname, prog, NULL); + printk("start_debugger : exec of gdb failed, errno = %d\n", + errno); + } + if(child < 0){ + printk("start_debugger : fork for gdb failed, errno = %d\n", + errno); + return(-1); + } + *fd_out = slave; + return(child); +} + +/* + * 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: + */ |