diff options
Diffstat (limited to 'gdb/gdbserver/linux-low.c')
| -rw-r--r-- | gdb/gdbserver/linux-low.c | 211 |
1 files changed, 185 insertions, 26 deletions
diff --git a/gdb/gdbserver/linux-low.c b/gdb/gdbserver/linux-low.c index 55c187c1bd5..a3d6a54d9cf 100644 --- a/gdb/gdbserver/linux-low.c +++ b/gdb/gdbserver/linux-low.c @@ -1,5 +1,5 @@ /* Low level interface to ptrace, for the remote server for GDB. - Copyright 1995, 1996, 1998, 1999, 2000, 2001, 2002 + Copyright 1995, 1996, 1998, 1999, 2000, 2001, 2002, 2003, 2004 Free Software Foundation, Inc. This file is part of GDB. @@ -34,6 +34,7 @@ #include <string.h> #include <stdlib.h> #include <unistd.h> +#include <errno.h> /* ``all_threads'' is keyed by the LWP ID - it should be the thread ID instead, however. This requires changing the ID in place when we go from !using_threads @@ -52,7 +53,7 @@ int using_threads; static void linux_resume_one_process (struct inferior_list_entry *entry, int step, int signal); -static void linux_resume (int step, int signal); +static void linux_resume (struct thread_resume *resume_info); static void stop_all_processes (void); static int linux_wait_for_event (struct thread_info *child); @@ -69,8 +70,6 @@ struct pending_signals static int use_regsets_p = 1; #endif -extern int errno; - int debug_threads = 0; #define pid_of(proc) ((proc)->head.id) @@ -316,6 +315,7 @@ check_removed_breakpoint (struct process_info *event_child) (*the_low_target.set_pc) (stop_pc); /* We consumed the pending SIGTRAP. */ + event_child->pending_is_breakpoint = 0; event_child->status_pending_p = 0; event_child->status_pending = 0; @@ -596,7 +596,7 @@ linux_wait_for_event (struct thread_info *child) /* If we were single-stepping, we definitely want to report the SIGTRAP. The single-step operation has completed, so also - clear the stepping flag; in general this does not matter, + clear the stepping flag; in general this does not matter, because the SIGTRAP will be reported to the client, which will give us a new action for this thread, but clear it for consistency anyway. It's safe to clear the stepping flag @@ -652,10 +652,16 @@ retry: /* No stepping, no signal - unless one is pending already, of course. */ if (child == NULL) - linux_resume (0, 0); + { + struct thread_resume resume_info; + resume_info.thread = -1; + resume_info.step = resume_info.sig = resume_info.leave_stopped = 0; + linux_resume (&resume_info); + } } enable_async_io (); + unblock_async_io (); w = linux_wait_for_event (child); stop_all_processes (); disable_async_io (); @@ -835,7 +841,7 @@ linux_resume_one_process (struct inferior_list_entry *entry, check_removed_breakpoint (process); - if (debug_threads && the_low_target.get_pc != NULL) + if (debug_threads && the_low_target.get_pc != NULL) { fprintf (stderr, " "); (long) (*the_low_target.get_pc) (); @@ -868,33 +874,154 @@ linux_resume_one_process (struct inferior_list_entry *entry, perror_with_name ("ptrace"); } -/* This function is called once per process other than the first - one. The first process we are told the signal to continue - with, and whether to step or continue; for all others, any - existing signals will be marked in status_pending_p to be - reported momentarily, and we preserve the stepping flag. */ +static struct thread_resume *resume_ptr; + +/* This function is called once per thread. We look up the thread + in RESUME_PTR, and mark the thread with a pointer to the appropriate + resume request. + + This algorithm is O(threads * resume elements), but resume elements + is small (and will remain small at least until GDB supports thread + suspension). */ static void -linux_continue_one_process (struct inferior_list_entry *entry) +linux_set_resume_request (struct inferior_list_entry *entry) { struct process_info *process; + struct thread_info *thread; + int ndx; - process = (struct process_info *) entry; - linux_resume_one_process (entry, process->stepping, 0); + thread = (struct thread_info *) entry; + process = get_thread_process (thread); + + ndx = 0; + while (resume_ptr[ndx].thread != -1 && resume_ptr[ndx].thread != entry->id) + ndx++; + + process->resume = &resume_ptr[ndx]; } +/* This function is called once per thread. We check the thread's resume + request, which will tell us whether to resume, step, or leave the thread + stopped; and what signal, if any, it should be sent. For threads which + we aren't explicitly told otherwise, we preserve the stepping flag; this + is used for stepping over gdbserver-placed breakpoints. */ + static void -linux_resume (int step, int signal) +linux_continue_one_thread (struct inferior_list_entry *entry) { struct process_info *process; + struct thread_info *thread; + int step; + + thread = (struct thread_info *) entry; + process = get_thread_process (thread); + + if (process->resume->leave_stopped) + return; + + if (process->resume->thread == -1) + step = process->stepping || process->resume->step; + else + step = process->resume->step; + + linux_resume_one_process (&process->head, step, process->resume->sig); + + process->resume = NULL; +} + +/* This function is called once per thread. We check the thread's resume + request, which will tell us whether to resume, step, or leave the thread + stopped; and what signal, if any, it should be sent. We queue any needed + signals, since we won't actually resume. We already have a pending event + to report, so we don't need to preserve any step requests; they should + be re-issued if necessary. */ + +static void +linux_queue_one_thread (struct inferior_list_entry *entry) +{ + struct process_info *process; + struct thread_info *thread; + + thread = (struct thread_info *) entry; + process = get_thread_process (thread); + + if (process->resume->leave_stopped) + return; + + /* If we have a new signal, enqueue the signal. */ + if (process->resume->sig != 0) + { + struct pending_signals *p_sig; + p_sig = malloc (sizeof (*p_sig)); + p_sig->prev = process->pending_signals; + p_sig->signal = process->resume->sig; + process->pending_signals = p_sig; + } + + process->resume = NULL; +} + +/* Set DUMMY if this process has an interesting status pending. */ +static int +resume_status_pending_p (struct inferior_list_entry *entry, void *flag_p) +{ + struct process_info *process = (struct process_info *) entry; + + /* Processes which will not be resumed are not interesting, because + we might not wait for them next time through linux_wait. */ + if (process->resume->leave_stopped) + return 0; - process = get_thread_process (current_inferior); + /* If this thread has a removed breakpoint, we won't have any + events to report later, so check now. check_removed_breakpoint + may clear status_pending_p. We avoid calling check_removed_breakpoint + for any thread that we are not otherwise going to resume - this + lets us preserve stopped status when two threads hit a breakpoint. + GDB removes the breakpoint to single-step a particular thread + past it, then re-inserts it and resumes all threads. We want + to report the second thread without resuming it in the interim. */ + if (process->status_pending_p) + check_removed_breakpoint (process); + + if (process->status_pending_p) + * (int *) flag_p = 1; + + return 0; +} + +static void +linux_resume (struct thread_resume *resume_info) +{ + int pending_flag; + + /* Yes, the use of a global here is rather ugly. */ + resume_ptr = resume_info; - /* If the current process has a status pending, this signal will - be enqueued and sent later. */ - linux_resume_one_process (&process->head, step, signal); + for_each_inferior (&all_threads, linux_set_resume_request); - if (cont_thread == 0 || cont_thread == -1) - for_each_inferior (&all_processes, linux_continue_one_process); + /* If there is a thread which would otherwise be resumed, which + has a pending status, then don't resume any threads - we can just + report the pending status. Make sure to queue any signals + that would otherwise be sent. */ + pending_flag = 0; + find_inferior (&all_processes, resume_status_pending_p, &pending_flag); + + if (debug_threads) + { + if (pending_flag) + fprintf (stderr, "Not resuming, pending status\n"); + else + fprintf (stderr, "Resuming, no pending status\n"); + } + + if (pending_flag) + for_each_inferior (&all_threads, linux_queue_one_thread); + else + { + block_async_io (); + enable_async_io (); + for_each_inferior (&all_threads, linux_continue_one_thread); + } } #ifdef HAVE_LINUX_USRREGS @@ -1153,28 +1280,33 @@ linux_store_registers (int regno) /* Copy LEN bytes from inferior's memory starting at MEMADDR to debugger memory starting at MYADDR. */ -static void +static int linux_read_memory (CORE_ADDR memaddr, char *myaddr, int len) { register int i; /* Round starting address down to longword boundary. */ register CORE_ADDR addr = memaddr & -(CORE_ADDR) sizeof (PTRACE_XFER_TYPE); /* Round ending address up; get number of longwords that makes. */ - register int count - = (((memaddr + len) - addr) + sizeof (PTRACE_XFER_TYPE) - 1) + register int count + = (((memaddr + len) - addr) + sizeof (PTRACE_XFER_TYPE) - 1) / sizeof (PTRACE_XFER_TYPE); /* Allocate buffer of that many longwords. */ - register PTRACE_XFER_TYPE *buffer + register PTRACE_XFER_TYPE *buffer = (PTRACE_XFER_TYPE *) alloca (count * sizeof (PTRACE_XFER_TYPE)); /* Read all the longwords */ for (i = 0; i < count; i++, addr += sizeof (PTRACE_XFER_TYPE)) { + errno = 0; buffer[i] = ptrace (PTRACE_PEEKTEXT, inferior_pid, (PTRACE_ARG3_TYPE) addr, 0); + if (errno) + return errno; } /* Copy appropriate bytes out of the buffer. */ memcpy (myaddr, (char *) buffer + (memaddr & (sizeof (PTRACE_XFER_TYPE) - 1)), len); + + return 0; } /* Copy LEN bytes of data from debugger memory at MYADDR @@ -1258,6 +1390,32 @@ linux_send_signal (int signum) kill (signal_pid, signum); } +/* Copy LEN bytes from inferior's auxiliary vector starting at OFFSET + to debugger memory starting at MYADDR. */ + +static int +linux_read_auxv (CORE_ADDR offset, char *myaddr, unsigned int len) +{ + char filename[PATH_MAX]; + int fd, n; + + snprintf (filename, sizeof filename, "/proc/%d/auxv", inferior_pid); + + fd = open (filename, O_RDONLY); + if (fd < 0) + return -1; + + if (offset != (CORE_ADDR) 0 + && lseek (fd, (off_t) offset, SEEK_SET) != (off_t) offset) + n = -1; + else + n = read (fd, myaddr, len); + + close (fd); + + return n; +} + static struct target_ops linux_target_ops = { linux_create_inferior, @@ -1273,6 +1431,7 @@ static struct target_ops linux_target_ops = { linux_write_memory, linux_look_up_symbols, linux_send_signal, + linux_read_auxv, }; static void |