diff options
Diffstat (limited to 'gdb/gdbserver')
| -rw-r--r-- | gdb/gdbserver/ChangeLog | 13 | ||||
| -rw-r--r-- | gdb/gdbserver/linux-low.c | 62 | ||||
| -rw-r--r-- | gdb/gdbserver/linux-low.h | 10 |
3 files changed, 76 insertions, 9 deletions
diff --git a/gdb/gdbserver/ChangeLog b/gdb/gdbserver/ChangeLog index 27af34e..f2e39fd 100644 --- a/gdb/gdbserver/ChangeLog +++ b/gdb/gdbserver/ChangeLog @@ -1,3 +1,16 @@ +2010-03-14 Pedro Alves <pedro@codesourcery.com> + + * linux-low.h (struct lwp_info): New fields + `stopped_by_watchpoint' and `stopped_data_address'. + * linux-low.c (linux_wait_for_lwp): Check for watchpoint triggers + here, and cache them in the lwp object. + (wait_for_sigstop): Check stopped_by_watchpoint lwp field + directly. + (linux_resume_one_lwp): Clear the lwp's stopped_by_watchpoint + field. + (linux_stopped_by_watchpoint): Rewrite. + (linux_stopped_data_address): Rewrite. + 2010-03-06 Simo Melenius <simo.melenius@iki.fi> * linux-low.c (linux_wait_for_lwp): Fetch the regcache after diff --git a/gdb/gdbserver/linux-low.c b/gdb/gdbserver/linux-low.c index 6499ca7..31ee6e9 100644 --- a/gdb/gdbserver/linux-low.c +++ b/gdb/gdbserver/linux-low.c @@ -1062,6 +1062,51 @@ retry: new_inferior = 0; } + /* Fetch the possibly triggered data watchpoint info and store it in + CHILD. + + On some archs, like x86, that use debug registers to set + watchpoints, it's possible that the way to know which watched + address trapped, is to check the register that is used to select + which address to watch. Problem is, between setting the + watchpoint and reading back which data address trapped, the user + may change the set of watchpoints, and, as a consequence, GDB + changes the debug registers in the inferior. To avoid reading + back a stale stopped-data-address when that happens, we cache in + LP the fact that a watchpoint trapped, and the corresponding data + address, as soon as we see CHILD stop with a SIGTRAP. If GDB + changes the debug registers meanwhile, we have the cached data we + can rely on. */ + + if (WIFSTOPPED (*wstatp) && WSTOPSIG (*wstatp) == SIGTRAP) + { + if (the_low_target.stopped_by_watchpoint == NULL) + { + child->stopped_by_watchpoint = 0; + } + else + { + struct thread_info *saved_inferior; + + saved_inferior = current_inferior; + current_inferior = get_lwp_thread (child); + + child->stopped_by_watchpoint + = the_low_target.stopped_by_watchpoint (); + + if (child->stopped_by_watchpoint) + { + if (the_low_target.stopped_data_address != NULL) + child->stopped_data_address + = the_low_target.stopped_data_address (); + else + child->stopped_data_address = 0; + } + + current_inferior = saved_inferior; + } + } + if (debug_threads && WIFSTOPPED (*wstatp) && the_low_target.get_pc != NULL) @@ -1724,7 +1769,7 @@ wait_for_sigstop (struct inferior_list_entry *entry) signal. */ if (WSTOPSIG (wstat) == SIGTRAP && lwp->stepping - && !linux_stopped_by_watchpoint ()) + && !lwp->stopped_by_watchpoint) { if (debug_threads) fprintf (stderr, " single-step SIGTRAP ignored\n"); @@ -1878,6 +1923,7 @@ linux_resume_one_lwp (struct lwp_info *lwp, get_lwp_thread (lwp)); errno = 0; lwp->stopped = 0; + lwp->stopped_by_watchpoint = 0; lwp->stepping = step; ptrace (step ? PTRACE_SINGLESTEP : PTRACE_CONT, lwpid_of (lwp), 0, /* Coerce to a uintptr_t first to avoid potential gcc warning @@ -2817,19 +2863,17 @@ linux_remove_point (char type, CORE_ADDR addr, int len) static int linux_stopped_by_watchpoint (void) { - if (the_low_target.stopped_by_watchpoint != NULL) - return the_low_target.stopped_by_watchpoint (); - else - return 0; + struct lwp_info *lwp = get_thread_lwp (current_inferior); + + return lwp->stopped_by_watchpoint; } static CORE_ADDR linux_stopped_data_address (void) { - if (the_low_target.stopped_data_address != NULL) - return the_low_target.stopped_data_address (); - else - return 0; + struct lwp_info *lwp = get_thread_lwp (current_inferior); + + return lwp->stopped_data_address; } #if defined(__UCLIBC__) && defined(HAS_NOMMU) diff --git a/gdb/gdbserver/linux-low.h b/gdb/gdbserver/linux-low.h index 82ad00c..82f29d8 100644 --- a/gdb/gdbserver/linux-low.h +++ b/gdb/gdbserver/linux-low.h @@ -161,6 +161,16 @@ struct lwp_info int pending_is_breakpoint; CORE_ADDR pending_stop_pc; + /* STOPPED_BY_WATCHPOINT is non-zero if this LWP stopped with a data + watchpoint trap. */ + int stopped_by_watchpoint; + + /* On architectures where it is possible to know the data address of + a triggered watchpoint, STOPPED_DATA_ADDRESS is non-zero, and + contains such data address. Only valid if STOPPED_BY_WATCHPOINT + is true. */ + CORE_ADDR stopped_data_address; + /* If this is non-zero, it is a breakpoint to be reinserted at our next stop (SIGTRAP stops only). */ CORE_ADDR bp_reinsert; |