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Re: [RFC 1/3] catch syscall -- try 6 -- Source-code modifications
Hi Eli,
On Friday 11 September 2009, Eli Zaretskii wrote:
> I have one more small request:
> > + /* Check if the user provided a syscall name or a number. */
> > + syscall_number = (int) strtol (cur_name, &endptr, 10);
>
> This forces the user to specify the system call numbers in decimal.
> However, sometimes it might be more convenient to use hex. For
> example, I'm planning to add support for this to the DJGPP port, where
> the various software interrupts and their functions are known to
> people by their hex numbers, e.g. Interrupt 0x21 function 0x2a is the
> DOS system call to get the system clock date. Asking the users to
> translate those into decimal would be a nuisance.
>
> So can we use zero instead of 10 for the last argument of this call to
> strtol?
Sure, I should have used zero since the start. Sorry about that, it's fixed
(and tested) now.
> Finally, a minor nit:
> > + while (*arg != '\0')
> > + {
> > + int i, syscall_number;
> > + char *endptr;
> > + char cur_name[128];
> > + struct syscall s;
> > +
> > + /* Skip whitespace. */
> > + while (isspace (*arg))
> > + arg++;
> > +
> > + for (i = 0; arg[i] && !isspace (arg[i]); ++i)
> > + cur_name[i] = arg[i];
> > + cur_name[i] = '\0';
> > + arg += i;
>
> The last loop does not take care not to overrun the 128-character
> limit that cur_name[] imposes on the length of syscall names, and will
> happily smash the stack if GDB is fed a very long string.
Ops, sorry about that too :-)... Thank you for pointing this nit, I've fixed
it too (and tested, of course).
What about the patch now? Ok to check in?
Regards,
--
Sérgio Durigan Júnior
Linux on Power Toolchain - Software Engineer
Linux Technology Center - LTC
IBM Brazil
diff --git a/gdb/amd64-linux-tdep.c b/gdb/amd64-linux-tdep.c
index 791e2c4..f527b7e 100644
--- a/gdb/amd64-linux-tdep.c
+++ b/gdb/amd64-linux-tdep.c
@@ -35,6 +35,10 @@
#include "amd64-tdep.h"
#include "solib-svr4.h"
+#include "xml-syscall.h"
+
+/* The syscall's XML filename for i386. */
+#define XML_SYSCALL_FILENAME_AMD64 "syscalls/amd64-linux.xml"
#include "record.h"
#include "linux-record.h"
@@ -174,6 +178,28 @@ amd64_linux_sigcontext_addr (struct frame_info *this_frame)
}
+static LONGEST
+amd64_linux_get_syscall_number (struct gdbarch *gdbarch,
+ ptid_t ptid)
+{
+ struct regcache *regcache = get_thread_regcache (ptid);
+ enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
+ /* The content of a register. */
+ gdb_byte buf[8];
+ /* The result. */
+ LONGEST ret;
+
+ /* Getting the system call number from the register.
+ When dealing with x86_64 architecture, this information
+ is stored at %rax register. */
+ regcache_cooked_read (regcache, AMD64_LINUX_ORIG_RAX_REGNUM, buf);
+
+ ret = extract_signed_integer (buf, 8, byte_order);
+
+ return ret;
+}
+
+
/* From <asm/sigcontext.h>. */
static int amd64_linux_sc_reg_offset[] =
{
@@ -1168,6 +1194,11 @@ amd64_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
set_gdbarch_register_type (gdbarch, amd64_linux_register_type);
set_gdbarch_register_reggroup_p (gdbarch, amd64_linux_register_reggroup_p);
+ /* Functions for 'catch syscall'. */
+ set_xml_syscall_file_name (XML_SYSCALL_FILENAME_AMD64);
+ set_gdbarch_get_syscall_number (gdbarch,
+ amd64_linux_get_syscall_number);
+
/* Enable TLS support. */
set_gdbarch_fetch_tls_load_module_address (gdbarch,
svr4_fetch_objfile_link_map);
diff --git a/gdb/breakpoint.c b/gdb/breakpoint.c
index 9f50872..811cdfb 100644
--- a/gdb/breakpoint.c
+++ b/gdb/breakpoint.c
@@ -60,6 +60,7 @@
#include "wrapper.h"
#include "valprint.h"
#include "jit.h"
+#include "xml-syscall.h"
/* readline include files */
#include "readline/readline.h"
@@ -204,6 +205,8 @@ static int is_hardware_watchpoint (struct breakpoint *bpt);
static void insert_breakpoint_locations (void);
+static int syscall_catchpoint_p (struct breakpoint *b);
+
static void tracepoints_info (char *, int);
static void delete_trace_command (char *, int);
@@ -4445,6 +4448,7 @@ set_raw_breakpoint_without_location (struct gdbarch *gdbarch,
b->frame_id = null_frame_id;
b->forked_inferior_pid = null_ptid;
b->exec_pathname = NULL;
+ b->syscalls_to_be_caught = NULL;
b->ops = NULL;
b->condition_not_parsed = 0;
@@ -4939,7 +4943,266 @@ static struct breakpoint_ops catch_vfork_breakpoint_ops =
print_mention_catch_vfork
};
-/* Create a new breakpoint of the bp_catchpoint kind and return it.
+/* Implement the "insert" breakpoint_ops method for syscall
+ catchpoints. */
+
+static void
+insert_catch_syscall (struct breakpoint *b)
+{
+ struct inferior *inf = current_inferior ();
+
+ ++inf->total_syscalls_count;
+ if (!b->syscalls_to_be_caught)
+ ++inf->any_syscall_count;
+ else
+ {
+ int i, iter;
+ for (i = 0;
+ VEC_iterate (int, b->syscalls_to_be_caught, i, iter);
+ i++)
+ {
+ int elem;
+ if (iter >= VEC_length (int, inf->syscalls_counts))
+ {
+ int old_size = VEC_length (int, inf->syscalls_counts);
+ uintptr_t vec_addr_offset = old_size * ((uintptr_t) sizeof (int));
+ uintptr_t vec_addr;
+ VEC_safe_grow (int, inf->syscalls_counts, iter + 1);
+ vec_addr = (uintptr_t) VEC_address (int, inf->syscalls_counts) +
+ vec_addr_offset;
+ memset ((void *) vec_addr, 0,
+ (iter + 1 - old_size) * sizeof (int));
+ }
+ elem = VEC_index (int, inf->syscalls_counts, iter);
+ VEC_replace (int, inf->syscalls_counts, iter, ++elem);
+ }
+ }
+
+ target_set_syscall_catchpoint (PIDGET (inferior_ptid),
+ inf->total_syscalls_count != 0,
+ inf->any_syscall_count,
+ VEC_length (int, inf->syscalls_counts),
+ VEC_address (int, inf->syscalls_counts));
+}
+
+/* Implement the "remove" breakpoint_ops method for syscall
+ catchpoints. */
+
+static int
+remove_catch_syscall (struct breakpoint *b)
+{
+ struct inferior *inf = current_inferior ();
+
+ --inf->total_syscalls_count;
+ if (!b->syscalls_to_be_caught)
+ --inf->any_syscall_count;
+ else
+ {
+ int i, iter;
+ for (i = 0;
+ VEC_iterate (int, b->syscalls_to_be_caught, i, iter);
+ i++)
+ {
+ int elem;
+ if (iter >= VEC_length (int, inf->syscalls_counts))
+ /* Shouldn't happen. */
+ continue;
+ elem = VEC_index (int, inf->syscalls_counts, iter);
+ VEC_replace (int, inf->syscalls_counts, iter, --elem);
+ }
+ }
+
+ return target_set_syscall_catchpoint (PIDGET (inferior_ptid),
+ inf->total_syscalls_count != 0,
+ inf->any_syscall_count,
+ VEC_length (int, inf->syscalls_counts),
+ VEC_address (int, inf->syscalls_counts));
+}
+
+/* Implement the "breakpoint_hit" breakpoint_ops method for syscall
+ catchpoints. */
+
+static int
+breakpoint_hit_catch_syscall (struct breakpoint *b)
+{
+ /* We must check if we are catching specific syscalls in this breakpoint.
+ If we are, then we must guarantee that the called syscall is the same
+ syscall we are catching. */
+ int syscall_number = 0;
+
+ if (!inferior_has_called_syscall (inferior_ptid, &syscall_number))
+ return 0;
+
+ /* Now, checking if the syscall is the same. */
+ if (b->syscalls_to_be_caught)
+ {
+ int i, iter;
+ for (i = 0;
+ VEC_iterate (int, b->syscalls_to_be_caught, i, iter);
+ i++)
+ if (syscall_number == iter)
+ break;
+ /* Not the same. */
+ if (!iter)
+ return 0;
+ }
+
+ return 1;
+}
+
+/* Implement the "print_it" breakpoint_ops method for syscall
+ catchpoints. */
+
+static enum print_stop_action
+print_it_catch_syscall (struct breakpoint *b)
+{
+ /* These are needed because we want to know in which state a
+ syscall is. It can be in the TARGET_WAITKIND_SYSCALL_ENTRY
+ or TARGET_WAITKIND_SYSCALL_RETURN, and depending on it we
+ must print "called syscall" or "returned from syscall". */
+ ptid_t ptid;
+ struct target_waitstatus last;
+ struct syscall s;
+ struct cleanup *old_chain;
+ char *syscall_id;
+
+ get_last_target_status (&ptid, &last);
+
+ get_syscall_by_number (last.value.syscall_number, &s);
+
+ annotate_catchpoint (b->number);
+
+ if (s.name == NULL)
+ syscall_id = xstrprintf ("%d", last.value.syscall_number);
+ else
+ syscall_id = xstrprintf ("'%s'", s.name);
+
+ old_chain = make_cleanup (xfree, syscall_id);
+
+ if (last.kind == TARGET_WAITKIND_SYSCALL_ENTRY)
+ printf_filtered (_("\nCatchpoint %d (call to syscall %s), "),
+ b->number, syscall_id);
+ else if (last.kind == TARGET_WAITKIND_SYSCALL_RETURN)
+ printf_filtered (_("\nCatchpoint %d (returned from syscall %s), "),
+ b->number, syscall_id);
+
+ do_cleanups (old_chain);
+
+ return PRINT_SRC_AND_LOC;
+}
+
+/* Implement the "print_one" breakpoint_ops method for syscall
+ catchpoints. */
+
+static void
+print_one_catch_syscall (struct breakpoint *b,
+ struct bp_location **last_loc)
+{
+ struct value_print_options opts;
+
+ get_user_print_options (&opts);
+ /* Field 4, the address, is omitted (which makes the columns
+ not line up too nicely with the headers, but the effect
+ is relatively readable). */
+ if (opts.addressprint)
+ ui_out_field_skip (uiout, "addr");
+ annotate_field (5);
+
+ if (b->syscalls_to_be_caught
+ && VEC_length (int, b->syscalls_to_be_caught) > 1)
+ ui_out_text (uiout, "syscalls \"");
+ else
+ ui_out_text (uiout, "syscall \"");
+
+ if (b->syscalls_to_be_caught)
+ {
+ int i, iter;
+ char *text = xstrprintf ("%s", "");
+ for (i = 0;
+ VEC_iterate (int, b->syscalls_to_be_caught, i, iter);
+ i++)
+ {
+ char *x = text;
+ struct syscall s;
+ get_syscall_by_number (iter, &s);
+
+ if (s.name != NULL)
+ text = xstrprintf ("%s%s, ", text, s.name);
+ else
+ text = xstrprintf ("%s%d, ", text, iter);
+
+ /* We have to xfree the last 'text' (now stored at 'x')
+ because xstrprintf dinamically allocates new space for it
+ on every call. */
+ xfree (x);
+ }
+ /* Remove the last comma. */
+ text[strlen (text) - 2] = '\0';
+ ui_out_field_string (uiout, "what", text);
+ }
+ else
+ ui_out_field_string (uiout, "what", "<any syscall>");
+ ui_out_text (uiout, "\" ");
+}
+
+/* Implement the "print_mention" breakpoint_ops method for syscall
+ catchpoints. */
+
+static void
+print_mention_catch_syscall (struct breakpoint *b)
+{
+ if (b->syscalls_to_be_caught)
+ {
+ int i, iter;
+
+ if (VEC_length (int, b->syscalls_to_be_caught) > 1)
+ printf_filtered (_("Catchpoint %d (syscalls"), b->number);
+ else
+ printf_filtered (_("Catchpoint %d (syscall"), b->number);
+
+ for (i = 0;
+ VEC_iterate (int, b->syscalls_to_be_caught, i, iter);
+ i++)
+ {
+ struct syscall s;
+ get_syscall_by_number (iter, &s);
+
+ if (s.name)
+ printf_filtered (" '%s' [%d]", s.name, s.number);
+ else
+ printf_filtered (" %d", s.number);
+ }
+ printf_filtered (")");
+ }
+ else
+ printf_filtered (_("Catchpoint %d (any syscall)"),
+ b->number);
+}
+
+/* The breakpoint_ops structure to be used in syscall catchpoints. */
+
+static struct breakpoint_ops catch_syscall_breakpoint_ops =
+{
+ insert_catch_syscall,
+ remove_catch_syscall,
+ breakpoint_hit_catch_syscall,
+ print_it_catch_syscall,
+ print_one_catch_syscall,
+ print_mention_catch_syscall
+};
+
+/* Returns non-zero if 'b' is a syscall catchpoint. */
+
+static int
+syscall_catchpoint_p (struct breakpoint *b)
+{
+ return (b->ops == &catch_syscall_breakpoint_ops);
+}
+
+/* Create a new breakpoint of the bp_catchpoint kind and return it,
+ but does NOT mention it nor update the global location list.
+ This is useful if you need to fill more fields in the
+ struct breakpoint before calling mention.
If TEMPFLAG is non-zero, then make the breakpoint temporary.
If COND_STRING is not NULL, then store it in the breakpoint.
@@ -4947,16 +5210,14 @@ static struct breakpoint_ops catch_vfork_breakpoint_ops =
to the catchpoint. */
static struct breakpoint *
-create_catchpoint (struct gdbarch *gdbarch, int tempflag,
- char *cond_string, struct breakpoint_ops *ops)
+create_catchpoint_without_mention (struct gdbarch *gdbarch, int tempflag,
+ char *cond_string,
+ struct breakpoint_ops *ops)
{
struct symtab_and_line sal;
struct breakpoint *b;
init_sal (&sal);
- sal.pc = 0;
- sal.symtab = NULL;
- sal.line = 0;
b = set_raw_breakpoint (gdbarch, sal, bp_catchpoint);
set_breakpoint_count (breakpoint_count + 1);
@@ -4969,6 +5230,23 @@ create_catchpoint (struct gdbarch *gdbarch, int tempflag,
b->disposition = tempflag ? disp_del : disp_donttouch;
b->ops = ops;
+ return b;
+}
+
+/* Create a new breakpoint of the bp_catchpoint kind and return it.
+
+ If TEMPFLAG is non-zero, then make the breakpoint temporary.
+ If COND_STRING is not NULL, then store it in the breakpoint.
+ OPS, if not NULL, is the breakpoint_ops structure associated
+ to the catchpoint. */
+
+static struct breakpoint *
+create_catchpoint (struct gdbarch *gdbarch, int tempflag,
+ char *cond_string, struct breakpoint_ops *ops)
+{
+ struct breakpoint *b =
+ create_catchpoint_without_mention (gdbarch, tempflag, cond_string, ops);
+
mention (b);
update_global_location_list (1);
@@ -5055,6 +5333,22 @@ static struct breakpoint_ops catch_exec_breakpoint_ops =
print_mention_catch_exec
};
+static void
+create_syscall_event_catchpoint (int tempflag, VEC(int) *filter,
+ struct breakpoint_ops *ops)
+{
+ struct gdbarch *gdbarch = get_current_arch ();
+ struct breakpoint *b =
+ create_catchpoint_without_mention (gdbarch, tempflag, NULL, ops);
+
+ b->syscalls_to_be_caught = filter;
+
+ /* Now, we have to mention the breakpoint and update the global
+ location list. */
+ mention (b);
+ update_global_location_list (1);
+}
+
static int
hw_breakpoint_used_count (void)
{
@@ -7150,6 +7444,113 @@ catch_ada_exception_command (char *arg, int from_tty,
from_tty);
}
+/* Cleanup function for a syscall filter list. */
+static void
+clean_up_filters (void *arg)
+{
+ VEC(int) *iter = *(VEC(int) **) arg;
+ VEC_free (int, iter);
+}
+
+/* Splits the argument using space as delimiter. Returns an xmalloc'd
+ filter list, or NULL if no filtering is required. */
+static VEC(int) *
+catch_syscall_split_args (char *arg)
+{
+ VEC(int) *result = NULL;
+ struct cleanup *cleanup = make_cleanup (clean_up_filters, &result);
+
+ while (*arg != '\0')
+ {
+ int i, syscall_number;
+ char *endptr;
+ char cur_name[128];
+ struct syscall s;
+
+ /* Skip whitespace. */
+ while (isspace (*arg))
+ arg++;
+
+ for (i = 0; i < 127 && arg[i] && !isspace (arg[i]); ++i)
+ cur_name[i] = arg[i];
+ cur_name[i] = '\0';
+ arg += i;
+
+ /* Check if the user provided a syscall name or a number. */
+ syscall_number = (int) strtol (cur_name, &endptr, 0);
+ if (*endptr == '\0')
+ {
+ get_syscall_by_number (syscall_number, &s);
+
+ if (s.name == NULL)
+ /* We can issue just a warning, but still create the catchpoint.
+ This is because, even not knowing the syscall name that
+ this number represents, we can still try to catch the syscall
+ number. */
+ warning (_("The number '%d' does not represent a known syscall."),
+ syscall_number);
+ }
+ else
+ {
+ /* We have a name. Let's check if it's valid and convert it
+ to a number. */
+ get_syscall_by_name (cur_name, &s);
+
+ if (s.number == UNKNOWN_SYSCALL)
+ /* Here we have to issue an error instead of a warning, because
+ GDB cannot do anything useful if there's no syscall number to
+ be caught. */
+ error (_("Unknown syscall name '%s'."), cur_name);
+ }
+
+ /* Ok, it's valid. */
+ VEC_safe_push (int, result, s.number);
+ }
+
+ discard_cleanups (cleanup);
+ return result;
+}
+
+/* Implement the "catch syscall" command. */
+
+static void
+catch_syscall_command_1 (char *arg, int from_tty, struct cmd_list_element *command)
+{
+ int tempflag;
+ VEC(int) *filter;
+ struct syscall s;
+ struct gdbarch *gdbarch = get_current_arch ();
+
+ /* Checking if the feature if supported. */
+ if (gdbarch_get_syscall_number_p (gdbarch) == 0)
+ error (_("The feature 'catch syscall' is not supported on \
+this architeture yet."));
+
+ tempflag = get_cmd_context (command) == CATCH_TEMPORARY;
+
+ ep_skip_leading_whitespace (&arg);
+
+ /* We need to do this first "dummy" translation in order
+ to get the syscall XML file loaded or, most important,
+ to display a warning to the user if there's no XML file
+ for his/her architecture. */
+ get_syscall_by_number (0, &s);
+
+ /* The allowed syntax is:
+ catch syscall
+ catch syscall <name | number> [<name | number> ... <name | number>]
+
+ Let's check if there's a syscall name. */
+
+ if (arg != NULL)
+ filter = catch_syscall_split_args (arg);
+ else
+ filter = NULL;
+
+ create_syscall_event_catchpoint (tempflag, filter,
+ &catch_syscall_breakpoint_ops);
+}
+
/* Implement the "catch assert" command. */
static void
@@ -7616,6 +8017,7 @@ delete_breakpoint (struct breakpoint *bpt)
xfree (bpt->source_file);
if (bpt->exec_pathname != NULL)
xfree (bpt->exec_pathname);
+ clean_up_filters (&bpt->syscalls_to_be_caught);
/* Be sure no bpstat's are pointing at it after it's been freed. */
/* FIXME, how can we find all bpstat's?
@@ -8552,6 +8954,60 @@ single_step_breakpoint_inserted_here_p (CORE_ADDR pc)
return 0;
}
+/* Returns 0 if 'bp' is NOT a syscall catchpoint,
+ non-zero otherwise. */
+static int
+is_syscall_catchpoint_enabled (struct breakpoint *bp)
+{
+ if (syscall_catchpoint_p (bp)
+ && bp->enable_state != bp_disabled
+ && bp->enable_state != bp_call_disabled)
+ return 1;
+ else
+ return 0;
+}
+
+int
+catch_syscall_enabled (void)
+{
+ struct inferior *inf = current_inferior ();
+
+ return inf->total_syscalls_count != 0;
+}
+
+int
+catching_syscall_number (int syscall_number)
+{
+ struct breakpoint *bp;
+
+ ALL_BREAKPOINTS (bp)
+ if (is_syscall_catchpoint_enabled (bp))
+ {
+ if (bp->syscalls_to_be_caught)
+ {
+ int i, iter;
+ for (i = 0;
+ VEC_iterate (int, bp->syscalls_to_be_caught, i, iter);
+ i++)
+ if (syscall_number == iter)
+ return 1;
+ }
+ else
+ return 1;
+ }
+
+ return 0;
+}
+
+/* Complete syscall names. Used by "catch syscall". */
+static char **
+catch_syscall_completer (struct cmd_list_element *cmd,
+ char *text, char *word)
+{
+ const char **list = get_syscall_names ();
+ return (list == NULL) ? NULL : complete_on_enum (list, text, word);
+}
+
/* Tracepoint-specific operations. */
/* Set tracepoint count to NUM. */
@@ -8903,6 +9359,8 @@ static void
add_catch_command (char *name, char *docstring,
void (*sfunc) (char *args, int from_tty,
struct cmd_list_element *command),
+ char **(*completer) (struct cmd_list_element *cmd,
+ char *text, char *word),
void *user_data_catch,
void *user_data_tcatch)
{
@@ -8912,11 +9370,13 @@ add_catch_command (char *name, char *docstring,
&catch_cmdlist);
set_cmd_sfunc (command, sfunc);
set_cmd_context (command, user_data_catch);
+ set_cmd_completer (command, completer);
command = add_cmd (name, class_breakpoint, NULL, docstring,
&tcatch_cmdlist);
set_cmd_sfunc (command, sfunc);
set_cmd_context (command, user_data_tcatch);
+ set_cmd_completer (command, completer);
}
void
@@ -9190,36 +9650,53 @@ Set temporary catchpoints to catch events."),
Catch an exception, when caught.\n\
With an argument, catch only exceptions with the given name."),
catch_catch_command,
+ NULL,
CATCH_PERMANENT,
CATCH_TEMPORARY);
add_catch_command ("throw", _("\
Catch an exception, when thrown.\n\
With an argument, catch only exceptions with the given name."),
catch_throw_command,
+ NULL,
CATCH_PERMANENT,
CATCH_TEMPORARY);
add_catch_command ("fork", _("Catch calls to fork."),
catch_fork_command_1,
+ NULL,
(void *) (uintptr_t) catch_fork_permanent,
(void *) (uintptr_t) catch_fork_temporary);
add_catch_command ("vfork", _("Catch calls to vfork."),
catch_fork_command_1,
+ NULL,
(void *) (uintptr_t) catch_vfork_permanent,
(void *) (uintptr_t) catch_vfork_temporary);
add_catch_command ("exec", _("Catch calls to exec."),
catch_exec_command_1,
+ NULL,
+ CATCH_PERMANENT,
+ CATCH_TEMPORARY);
+ add_catch_command ("syscall", _("\
+Catch system calls by their names and/or numbers.\n\
+Arguments say which system calls to catch. If no arguments\n\
+are given, every system call will be caught.\n\
+Arguments, if given, should be one or more system call names\n\
+(if your system supports that), or system call numbers."),
+ catch_syscall_command_1,
+ catch_syscall_completer,
CATCH_PERMANENT,
CATCH_TEMPORARY);
add_catch_command ("exception", _("\
Catch Ada exceptions, when raised.\n\
With an argument, catch only exceptions with the given name."),
catch_ada_exception_command,
+ NULL,
CATCH_PERMANENT,
CATCH_TEMPORARY);
add_catch_command ("assert", _("\
Catch failed Ada assertions, when raised.\n\
With an argument, catch only exceptions with the given name."),
catch_assert_command,
+ NULL,
CATCH_PERMANENT,
CATCH_TEMPORARY);
diff --git a/gdb/breakpoint.h b/gdb/breakpoint.h
index 70b1398..ba499c6 100644
--- a/gdb/breakpoint.h
+++ b/gdb/breakpoint.h
@@ -33,7 +33,8 @@ struct block;
#define BREAKPOINT_MAX 16
-/* Type of breakpoint. */
+
+/* Type of breakpoint. */
/* FIXME In the future, we should fold all other breakpoint-like things into
here. This includes:
@@ -359,6 +360,9 @@ enum watchpoint_triggered
watch_triggered_yes
};
+/* This is used to declare the VEC syscalls_to_be_caught. */
+DEF_VEC_I(int);
+
typedef struct bp_location *bp_location_p;
DEF_VEC_P(bp_location_p);
@@ -469,6 +473,12 @@ struct breakpoint
triggered. */
char *exec_pathname;
+ /* Syscall numbers used for the 'catch syscall' feature.
+ If no syscall has been specified for filtering, its value is NULL.
+ Otherwise, it holds a list of all syscalls to be caught.
+ The list elements are allocated with xmalloc. */
+ VEC(int) *syscalls_to_be_caught;
+
/* Methods associated with this breakpoint. */
struct breakpoint_ops *ops;
@@ -924,6 +934,15 @@ extern int breakpoints_always_inserted_mode (void);
in our opinion won't ever trigger. */
extern void breakpoint_retire_moribund (void);
+/* Checks if we are catching syscalls or not.
+ Returns 0 if not, greater than 0 if we are. */
+extern int catch_syscall_enabled (void);
+
+/* Checks if we are catching syscalls with the specific
+ syscall_number. Used for "filtering" the catchpoints.
+ Returns 0 if not, greater than 0 if we are. */
+extern int catching_syscall_number (int syscall_number);
+
/* Tell a breakpoint to be quiet. */
extern void make_breakpoint_silent (struct breakpoint *);
diff --git a/gdb/gdbarch.c b/gdb/gdbarch.c
index a20df00..e1b9d0d 100644
--- a/gdb/gdbarch.c
+++ b/gdb/gdbarch.c
@@ -244,6 +244,7 @@ struct gdbarch
gdbarch_target_signal_to_host_ftype *target_signal_to_host;
gdbarch_get_siginfo_type_ftype *get_siginfo_type;
gdbarch_record_special_symbol_ftype *record_special_symbol;
+ gdbarch_get_syscall_number_ftype *get_syscall_number;
int has_global_solist;
int has_global_breakpoints;
};
@@ -381,6 +382,7 @@ struct gdbarch startup_gdbarch =
default_target_signal_to_host, /* target_signal_to_host */
0, /* get_siginfo_type */
0, /* record_special_symbol */
+ 0, /* get_syscall_number */
0, /* has_global_solist */
0, /* has_global_breakpoints */
/* startup_gdbarch() */
@@ -637,6 +639,7 @@ verify_gdbarch (struct gdbarch *gdbarch)
/* Skip verify of target_signal_to_host, invalid_p == 0 */
/* Skip verify of get_siginfo_type, has predicate */
/* Skip verify of record_special_symbol, has predicate */
+ /* Skip verify of get_syscall_number, has predicate */
/* Skip verify of has_global_solist, invalid_p == 0 */
/* Skip verify of has_global_breakpoints, invalid_p == 0 */
buf = ui_file_xstrdup (log, &length);
@@ -866,6 +869,12 @@ gdbarch_dump (struct gdbarch *gdbarch, struct ui_file *file)
"gdbarch_dump: get_siginfo_type = <%s>\n",
host_address_to_string (gdbarch->get_siginfo_type));
fprintf_unfiltered (file,
+ "gdbarch_dump: gdbarch_get_syscall_number_p() = %d\n",
+ gdbarch_get_syscall_number_p (gdbarch));
+ fprintf_unfiltered (file,
+ "gdbarch_dump: get_syscall_number = <%s>\n",
+ host_address_to_string (gdbarch->get_syscall_number));
+ fprintf_unfiltered (file,
"gdbarch_dump: has_global_breakpoints = %s\n",
plongest (gdbarch->has_global_breakpoints));
fprintf_unfiltered (file,
@@ -3381,6 +3390,30 @@ set_gdbarch_record_special_symbol (struct gdbarch *gdbarch,
}
int
+gdbarch_get_syscall_number_p (struct gdbarch *gdbarch)
+{
+ gdb_assert (gdbarch != NULL);
+ return gdbarch->get_syscall_number != NULL;
+}
+
+LONGEST
+gdbarch_get_syscall_number (struct gdbarch *gdbarch, ptid_t ptid)
+{
+ gdb_assert (gdbarch != NULL);
+ gdb_assert (gdbarch->get_syscall_number != NULL);
+ if (gdbarch_debug >= 2)
+ fprintf_unfiltered (gdb_stdlog, "gdbarch_get_syscall_number called\n");
+ return gdbarch->get_syscall_number (gdbarch, ptid);
+}
+
+void
+set_gdbarch_get_syscall_number (struct gdbarch *gdbarch,
+ gdbarch_get_syscall_number_ftype get_syscall_number)
+{
+ gdbarch->get_syscall_number = get_syscall_number;
+}
+
+int
gdbarch_has_global_solist (struct gdbarch *gdbarch)
{
gdb_assert (gdbarch != NULL);
diff --git a/gdb/gdbarch.h b/gdb/gdbarch.h
index 9ffef7e..027541d 100644
--- a/gdb/gdbarch.h
+++ b/gdb/gdbarch.h
@@ -52,6 +52,7 @@ struct bp_target_info;
struct target_desc;
struct displaced_step_closure;
struct core_regset_section;
+struct syscall;
/* The architecture associated with the connection to the target.
@@ -853,6 +854,15 @@ typedef void (gdbarch_record_special_symbol_ftype) (struct gdbarch *gdbarch, str
extern void gdbarch_record_special_symbol (struct gdbarch *gdbarch, struct objfile *objfile, asymbol *sym);
extern void set_gdbarch_record_special_symbol (struct gdbarch *gdbarch, gdbarch_record_special_symbol_ftype *record_special_symbol);
+/* Function for the 'catch syscall' feature.
+ Get architecture-specific system calls information from registers. */
+
+extern int gdbarch_get_syscall_number_p (struct gdbarch *gdbarch);
+
+typedef LONGEST (gdbarch_get_syscall_number_ftype) (struct gdbarch *gdbarch, ptid_t ptid);
+extern LONGEST gdbarch_get_syscall_number (struct gdbarch *gdbarch, ptid_t ptid);
+extern void set_gdbarch_get_syscall_number (struct gdbarch *gdbarch, gdbarch_get_syscall_number_ftype *get_syscall_number);
+
/* True if the list of shared libraries is one and only for all
processes, as opposed to a list of shared libraries per inferior.
This usually means that all processes, although may or may not share
@@ -870,6 +880,9 @@ extern void set_gdbarch_has_global_solist (struct gdbarch *gdbarch, int has_glob
extern int gdbarch_has_global_breakpoints (struct gdbarch *gdbarch);
extern void set_gdbarch_has_global_breakpoints (struct gdbarch *gdbarch, int has_global_breakpoints);
+/* Definition for an unknown syscall, used basically in error-cases. */
+#define UNKNOWN_SYSCALL (-1)
+
extern struct gdbarch_tdep *gdbarch_tdep (struct gdbarch *gdbarch);
diff --git a/gdb/gdbarch.sh b/gdb/gdbarch.sh
index 491efce..3a6e483 100755
--- a/gdb/gdbarch.sh
+++ b/gdb/gdbarch.sh
@@ -724,6 +724,11 @@ M:struct type *:get_siginfo_type:void:
# Record architecture-specific information from the symbol table.
M:void:record_special_symbol:struct objfile *objfile, asymbol *sym:objfile, sym
+# Function for the 'catch syscall' feature.
+
+# Get architecture-specific system calls information from registers.
+M:LONGEST:get_syscall_number:ptid_t ptid:ptid
+
# True if the list of shared libraries is one and only for all
# processes, as opposed to a list of shared libraries per inferior.
# This usually means that all processes, although may or may not share
@@ -848,6 +853,7 @@ struct bp_target_info;
struct target_desc;
struct displaced_step_closure;
struct core_regset_section;
+struct syscall;
/* The architecture associated with the connection to the target.
@@ -926,6 +932,9 @@ done
# close it off
cat <<EOF
+/* Definition for an unknown syscall, used basically in error-cases. */
+#define UNKNOWN_SYSCALL (-1)
+
extern struct gdbarch_tdep *gdbarch_tdep (struct gdbarch *gdbarch);
diff --git a/gdb/i386-linux-nat.c b/gdb/i386-linux-nat.c
index 991b27f..fe848ff 100644
--- a/gdb/i386-linux-nat.c
+++ b/gdb/i386-linux-nat.c
@@ -752,7 +752,12 @@ i386_linux_resume (struct target_ops *ops,
{
int pid = PIDGET (ptid);
- int request = PTRACE_CONT;
+ int request;
+
+ if (catch_syscall_enabled () > 0)
+ request = PTRACE_SYSCALL;
+ else
+ request = PTRACE_CONT;
if (step)
{
diff --git a/gdb/i386-linux-tdep.c b/gdb/i386-linux-tdep.c
index 748fda0..78fe88e 100644
--- a/gdb/i386-linux-tdep.c
+++ b/gdb/i386-linux-tdep.c
@@ -37,6 +37,10 @@
#include "symtab.h"
#include "arch-utils.h"
#include "regset.h"
+#include "xml-syscall.h"
+
+/* The syscall's XML filename for i386. */
+#define XML_SYSCALL_FILENAME_I386 "syscalls/i386-linux.xml"
#include "record.h"
#include "linux-record.h"
@@ -411,6 +415,27 @@ i386_linux_intx80_sysenter_record (struct regcache *regcache)
}
+static LONGEST
+i386_linux_get_syscall_number (struct gdbarch *gdbarch,
+ ptid_t ptid)
+{
+ struct regcache *regcache = get_thread_regcache (ptid);
+ enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
+ /* The content of a register. */
+ gdb_byte buf[4];
+ /* The result. */
+ LONGEST ret;
+
+ /* Getting the system call number from the register.
+ When dealing with x86 architecture, this information
+ is stored at %eax register. */
+ regcache_cooked_read (regcache, I386_LINUX_ORIG_EAX_REGNUM, buf);
+
+ ret = extract_signed_integer (buf, 4, byte_order);
+
+ return ret;
+}
+
/* The register sets used in GNU/Linux ELF core-dumps are identical to
the register sets in `struct user' that are used for a.out
core-dumps. These are also used by ptrace(2). The corresponding
@@ -697,6 +722,11 @@ i386_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
set_gdbarch_displaced_step_location (gdbarch,
displaced_step_at_entry_point);
+ /* Functions for 'catch syscall'. */
+ set_xml_syscall_file_name (XML_SYSCALL_FILENAME_I386);
+ set_gdbarch_get_syscall_number (gdbarch,
+ i386_linux_get_syscall_number);
+
set_gdbarch_get_siginfo_type (gdbarch, linux_get_siginfo_type);
}
diff --git a/gdb/inf-child.c b/gdb/inf-child.c
index 2ac7027..07ca814 100644
--- a/gdb/inf-child.c
+++ b/gdb/inf-child.c
@@ -148,6 +148,15 @@ inf_child_remove_exec_catchpoint (int pid)
}
static int
+inf_child_set_syscall_catchpoint (int pid, int needed, int any_count,
+ int table_size, int *table)
+{
+ /* This version of Unix doesn't support notification of syscall
+ events. */
+ return 0;
+}
+
+static int
inf_child_can_run (void)
{
return 1;
@@ -190,6 +199,7 @@ inf_child_target (void)
t->to_follow_fork = inf_child_follow_fork;
t->to_insert_exec_catchpoint = inf_child_insert_exec_catchpoint;
t->to_remove_exec_catchpoint = inf_child_remove_exec_catchpoint;
+ t->to_set_syscall_catchpoint = inf_child_set_syscall_catchpoint;
t->to_can_run = inf_child_can_run;
t->to_pid_to_exec_file = inf_child_pid_to_exec_file;
t->to_stratum = process_stratum;
diff --git a/gdb/inf-ptrace.c b/gdb/inf-ptrace.c
index 89a37a6..736154a 100644
--- a/gdb/inf-ptrace.c
+++ b/gdb/inf-ptrace.c
@@ -332,13 +332,18 @@ inf_ptrace_resume (struct target_ops *ops,
ptid_t ptid, int step, enum target_signal signal)
{
pid_t pid = ptid_get_pid (ptid);
- int request = PT_CONTINUE;
+ int request;
if (pid == -1)
/* Resume all threads. Traditionally ptrace() only supports
single-threaded processes, so simply resume the inferior. */
pid = ptid_get_pid (inferior_ptid);
+ if (catch_syscall_enabled () > 0)
+ request = PT_SYSCALL;
+ else
+ request = PT_CONTINUE;
+
if (step)
{
/* If this system does not support PT_STEP, a higher level
diff --git a/gdb/inferior.h b/gdb/inferior.h
index 7312e51..f1b5d17 100644
--- a/gdb/inferior.h
+++ b/gdb/inferior.h
@@ -425,6 +425,20 @@ struct inferior
/* Private data used by the target vector implementation. */
struct private_inferior *private;
+
+ /* We keep a count of the number of times the user has requested a
+ particular syscall to be tracked, and pass this information to the
+ target. This lets capable targets implement filtering directly. */
+
+ /* Number of times that "any" syscall is requested. */
+ int any_syscall_count;
+
+ /* Count of each system call. */
+ VEC(int) *syscalls_counts;
+
+ /* This counts all syscall catch requests, so we can readily determine
+ if any catching is necessary. */
+ int total_syscalls_count;
};
/* Create an empty inferior list, or empty the existing one. */
diff --git a/gdb/infrun.c b/gdb/infrun.c
index c907635..713810b 100644
--- a/gdb/infrun.c
+++ b/gdb/infrun.c
@@ -2042,6 +2042,10 @@ wait_for_inferior (int treat_exec_as_sigtrap)
state. */
old_chain = make_cleanup (finish_thread_state_cleanup, &minus_one_ptid);
+ if (ecs->ws.kind == TARGET_WAITKIND_SYSCALL_ENTRY
+ || ecs->ws.kind == TARGET_WAITKIND_SYSCALL_RETURN)
+ ecs->ws.value.syscall_number = UNKNOWN_SYSCALL;
+
/* Now figure out what to do with the result of the result. */
handle_inferior_event (ecs);
@@ -2378,6 +2382,56 @@ stepped_in_from (struct frame_info *frame, struct frame_id step_frame_id)
return 0;
}
+/* Auxiliary function that handles syscall entry/return events.
+ It returns 1 if the inferior should keep going (and GDB
+ should ignore the event), or 0 if the event deserves to be
+ processed. */
+static int
+deal_with_syscall_event (struct execution_control_state *ecs)
+{
+ struct regcache *regcache = get_thread_regcache (ecs->ptid);
+ struct gdbarch *gdbarch = get_regcache_arch (regcache);
+ int syscall_number = gdbarch_get_syscall_number (gdbarch,
+ ecs->ptid);
+ target_last_waitstatus.value.syscall_number = syscall_number;
+
+ if (catch_syscall_enabled () > 0
+ && catching_syscall_number (syscall_number) > 0)
+ {
+ if (debug_infrun)
+ fprintf_unfiltered (gdb_stdlog, "infrun: syscall number = '%d'\n",
+ syscall_number);
+ ecs->event_thread->stop_signal = TARGET_SIGNAL_TRAP;
+
+ if (!ptid_equal (ecs->ptid, inferior_ptid))
+ {
+ context_switch (ecs->ptid);
+ reinit_frame_cache ();
+ }
+
+ stop_pc = regcache_read_pc (get_thread_regcache (ecs->ptid));
+
+ ecs->event_thread->stop_bpstat = bpstat_stop_status (stop_pc, ecs->ptid);
+
+ ecs->random_signal = !bpstat_explains_signal (ecs->event_thread->stop_bpstat);
+
+ /* If no catchpoint triggered for this, then keep going. */
+ if (ecs->random_signal)
+ {
+ ecs->event_thread->stop_signal = TARGET_SIGNAL_0;
+ keep_going (ecs);
+ return 1;
+ }
+ return 0;
+ }
+ else
+ {
+ resume (0, TARGET_SIGNAL_0);
+ prepare_to_wait (ecs);
+ return 1;
+ }
+}
+
/* Given an execution control state that has been freshly filled in
by an event from the inferior, figure out what it means and take
appropriate action. */
@@ -2698,9 +2752,11 @@ handle_inferior_event (struct execution_control_state *ecs)
case TARGET_WAITKIND_SYSCALL_ENTRY:
if (debug_infrun)
fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_SYSCALL_ENTRY\n");
- resume (0, TARGET_SIGNAL_0);
- prepare_to_wait (ecs);
- return;
+ /* Getting the current syscall number */
+ if (deal_with_syscall_event (ecs) != 0)
+ return;
+ goto process_event_stop_test;
+ break;
/* Before examining the threads further, step this thread to
get it entirely out of the syscall. (We get notice of the
@@ -2710,9 +2766,10 @@ handle_inferior_event (struct execution_control_state *ecs)
case TARGET_WAITKIND_SYSCALL_RETURN:
if (debug_infrun)
fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_SYSCALL_RETURN\n");
- target_resume (ecs->ptid, 1, TARGET_SIGNAL_0);
- prepare_to_wait (ecs);
- return;
+ if (deal_with_syscall_event (ecs) != 0)
+ return;
+ goto process_event_stop_test;
+ break;
case TARGET_WAITKIND_STOPPED:
if (debug_infrun)
@@ -5614,6 +5671,25 @@ inferior_has_execd (ptid_t pid, char **execd_pathname)
return 1;
}
+int
+inferior_has_called_syscall (ptid_t pid, int *syscall_number)
+{
+ struct target_waitstatus last;
+ ptid_t last_ptid;
+
+ get_last_target_status (&last_ptid, &last);
+
+ if (last.kind != TARGET_WAITKIND_SYSCALL_ENTRY &&
+ last.kind != TARGET_WAITKIND_SYSCALL_RETURN)
+ return 0;
+
+ if (!ptid_equal (last_ptid, pid))
+ return 0;
+
+ *syscall_number = last.value.syscall_number;
+ return 1;
+}
+
/* Oft used ptids */
ptid_t null_ptid;
ptid_t minus_one_ptid;
diff --git a/gdb/linux-nat.c b/gdb/linux-nat.c
index 1308844..98f6347 100644
--- a/gdb/linux-nat.c
+++ b/gdb/linux-nat.c
@@ -67,6 +67,10 @@
# endif
#endif /* HAVE_PERSONALITY */
+/* To be used when one needs to know wether a
+ WSTOPSIG (status) is a syscall */
+#define TRAP_IS_SYSCALL (SIGTRAP | 0x80)
+
/* This comment documents high-level logic of this file.
Waiting for events in sync mode
@@ -279,6 +283,11 @@ struct simple_pid_list *stopped_pids;
static int linux_supports_tracefork_flag = -1;
+/* This variable is a tri-state flag: -1 for unknown, 0 if PTRACE_O_TRACESYSGOOD
+ can not be used, 1 if it can. */
+
+static int linux_supports_tracesysgood_flag = -1;
+
/* If we have PTRACE_O_TRACEFORK, this flag indicates whether we also have
PTRACE_O_TRACEVFORKDONE. */
@@ -290,6 +299,9 @@ static int linux_supports_tracevforkdone_flag = -1;
linux_nat_wait should behave as if async mode was off. */
static int linux_nat_async_mask_value = 1;
+/* Stores the current used ptrace() options. */
+static int current_ptrace_options = 0;
+
/* The read/write ends of the pipe registered as waitable file in the
event loop. */
static int linux_nat_event_pipe[2] = { -1, -1 };
@@ -525,6 +537,43 @@ linux_test_for_tracefork (int original_pid)
restore_child_signals_mask (&prev_mask);
}
+/* Determine if PTRACE_O_TRACESYSGOOD can be used to follow syscalls.
+
+ We try to enable syscall tracing on ORIGINAL_PID. If this fails,
+ we know that the feature is not available. This may change the tracing
+ options for ORIGINAL_PID, but we'll be setting them shortly anyway. */
+
+static void
+linux_test_for_tracesysgood (int original_pid)
+{
+ int ret;
+ sigset_t prev_mask;
+
+ /* We don't want those ptrace calls to be interrupted. */
+ block_child_signals (&prev_mask);
+
+ linux_supports_tracesysgood_flag = 0;
+
+ ret = ptrace (PTRACE_SETOPTIONS, original_pid, 0, PTRACE_O_TRACESYSGOOD);
+ if (ret != 0)
+ goto out;
+
+ linux_supports_tracesysgood_flag = 1;
+out:
+ restore_child_signals_mask (&prev_mask);
+}
+
+/* Determine wether we support PTRACE_O_TRACESYSGOOD option available.
+ This function also sets linux_supports_tracesysgood_flag. */
+
+static int
+linux_supports_tracesysgood (int pid)
+{
+ if (linux_supports_tracesysgood_flag == -1)
+ linux_test_for_tracesysgood (pid);
+ return linux_supports_tracesysgood_flag;
+}
+
/* Return non-zero iff we have tracefork functionality available.
This function also sets linux_supports_tracefork_flag. */
@@ -544,12 +593,27 @@ linux_supports_tracevforkdone (int pid)
return linux_supports_tracevforkdone_flag;
}
+static void
+linux_enable_tracesysgood (ptid_t ptid)
+{
+ int pid = ptid_get_lwp (ptid);
+
+ if (pid == 0)
+ pid = ptid_get_pid (ptid);
+
+ if (linux_supports_tracesysgood (pid) == 0)
+ return;
+
+ current_ptrace_options |= PTRACE_O_TRACESYSGOOD;
+
+ ptrace (PTRACE_SETOPTIONS, pid, 0, current_ptrace_options);
+}
+
void
linux_enable_event_reporting (ptid_t ptid)
{
int pid = ptid_get_lwp (ptid);
- int options;
if (pid == 0)
pid = ptid_get_pid (ptid);
@@ -557,15 +621,16 @@ linux_enable_event_reporting (ptid_t ptid)
if (! linux_supports_tracefork (pid))
return;
- options = PTRACE_O_TRACEFORK | PTRACE_O_TRACEVFORK | PTRACE_O_TRACEEXEC
- | PTRACE_O_TRACECLONE;
+ current_ptrace_options |= PTRACE_O_TRACEFORK | PTRACE_O_TRACEVFORK
+ | PTRACE_O_TRACEEXEC | PTRACE_O_TRACECLONE;
+
if (linux_supports_tracevforkdone (pid))
- options |= PTRACE_O_TRACEVFORKDONE;
+ current_ptrace_options |= PTRACE_O_TRACEVFORKDONE;
/* Do not enable PTRACE_O_TRACEEXIT until GDB is more prepared to support
read-only process state. */
- ptrace (PTRACE_SETOPTIONS, pid, 0, options);
+ ptrace (PTRACE_SETOPTIONS, pid, 0, current_ptrace_options);
}
static void
@@ -573,6 +638,7 @@ linux_child_post_attach (int pid)
{
linux_enable_event_reporting (pid_to_ptid (pid));
check_for_thread_db ();
+ linux_enable_tracesysgood (pid_to_ptid (pid));
}
static void
@@ -580,6 +646,7 @@ linux_child_post_startup_inferior (ptid_t ptid)
{
linux_enable_event_reporting (ptid);
check_for_thread_db ();
+ linux_enable_tracesysgood (ptid);
}
static int
@@ -810,6 +877,20 @@ linux_child_insert_exec_catchpoint (int pid)
error (_("Your system does not support exec catchpoints."));
}
+static int
+linux_child_set_syscall_catchpoint (int pid, int needed, int any_count,
+ int table_size, int *table)
+{
+ if (! linux_supports_tracesysgood (pid))
+ error (_("Your system does not support syscall catchpoints."));
+ /* On GNU/Linux, we ignore the arguments. It means that we only
+ enable the syscall catchpoints, but do not disable them.
+
+ Also, we do not use the `table' information because we do not
+ filter system calls here. We let GDB do the logic for us. */
+ return 0;
+}
+
/* On GNU/Linux there are no real LWP's. The closest thing to LWP's
are processes sharing the same VM space. A multi-threaded process
is basically a group of such processes. However, such a grouping
@@ -1982,6 +2063,47 @@ linux_handle_extended_wait (struct lwp_info *lp, int status,
return 0;
}
+ /* Used for 'catch syscall' feature. */
+ if (WSTOPSIG (status) == TRAP_IS_SYSCALL)
+ {
+ if (catch_syscall_enabled () == 0)
+ ourstatus->kind = TARGET_WAITKIND_IGNORE;
+ else
+ {
+ struct regcache *regcache = get_thread_regcache (lp->ptid);
+ struct gdbarch *gdbarch = get_regcache_arch (regcache);
+
+ ourstatus->value.syscall_number =
+ (int) gdbarch_get_syscall_number (gdbarch, lp->ptid);
+
+ /* If we are catching this specific syscall number, then we
+ should update the target_status to reflect which event
+ has occurred. But if this syscall is not to be caught,
+ then we can safely mark the event as a SYSCALL_RETURN.
+
+ This is particularly needed if:
+
+ - We are catching any syscalls, or
+ - We are catching the syscall "exit"
+
+ In this case, as the syscall "exit" *doesn't* return,
+ then GDB would be confused because it would mark the last
+ syscall event as a SYSCALL_ENTRY. After that, if we re-ran the
+ inferior GDB will think that the first syscall event is
+ the opposite of a SYSCALL_ENTRY, which is the SYSCALL_RETURN.
+ Therefore, GDB would report inverted syscall events. */
+ if (catching_syscall_number (ourstatus->value.syscall_number))
+ ourstatus->kind =
+ (lp->syscall_state == TARGET_WAITKIND_SYSCALL_ENTRY) ?
+ TARGET_WAITKIND_SYSCALL_RETURN : TARGET_WAITKIND_SYSCALL_ENTRY;
+ else
+ ourstatus->kind = TARGET_WAITKIND_SYSCALL_RETURN;
+
+ lp->syscall_state = ourstatus->kind;
+ }
+ return 0;
+ }
+
internal_error (__FILE__, __LINE__,
_("unknown ptrace event %d"), event);
}
@@ -2580,11 +2702,16 @@ linux_nat_filter_event (int lwpid, int status, int options)
}
/* Save the trap's siginfo in case we need it later. */
- if (WIFSTOPPED (status) && WSTOPSIG (status) == SIGTRAP)
+ if (WIFSTOPPED (status)
+ && (WSTOPSIG (status) == SIGTRAP || WSTOPSIG (status) == TRAP_IS_SYSCALL))
save_siginfo (lp);
- /* Handle GNU/Linux's extended waitstatus for trace events. */
- if (WIFSTOPPED (status) && WSTOPSIG (status) == SIGTRAP && status >> 16 != 0)
+ /* Handle GNU/Linux's extended waitstatus for trace events.
+ It is necessary to check if WSTOPSIG is signaling that
+ the inferior is entering/exiting a system call. */
+ if (WIFSTOPPED (status)
+ && ((WSTOPSIG (status) == TRAP_IS_SYSCALL)
+ || (WSTOPSIG (status) == SIGTRAP && status >> 16 != 0)))
{
if (debug_linux_nat)
fprintf_unfiltered (gdb_stdlog,
@@ -4510,6 +4637,7 @@ linux_target_install_ops (struct target_ops *t)
t->to_insert_fork_catchpoint = linux_child_insert_fork_catchpoint;
t->to_insert_vfork_catchpoint = linux_child_insert_vfork_catchpoint;
t->to_insert_exec_catchpoint = linux_child_insert_exec_catchpoint;
+ t->to_set_syscall_catchpoint = linux_child_set_syscall_catchpoint;
t->to_pid_to_exec_file = linux_child_pid_to_exec_file;
t->to_post_startup_inferior = linux_child_post_startup_inferior;
t->to_post_attach = linux_child_post_attach;
diff --git a/gdb/linux-nat.h b/gdb/linux-nat.h
index d1ed6fc..eae74f3 100644
--- a/gdb/linux-nat.h
+++ b/gdb/linux-nat.h
@@ -70,6 +70,13 @@ struct lwp_info
or to a local variable in lin_lwp_wait. */
struct target_waitstatus waitstatus;
+ /* Signal wether we are in a SYSCALL_ENTRY or
+ in a SYSCALL_RETURN event.
+ Values:
+ - TARGET_WAITKIND_SYSCALL_ENTRY
+ - TARGET_WAITKIND_SYSCALL_RETURN */
+ int syscall_state;
+
/* Next LWP in list. */
struct lwp_info *next;
};
diff --git a/gdb/ppc-linux-tdep.c b/gdb/ppc-linux-tdep.c
index f0f802c..d8211ed 100644
--- a/gdb/ppc-linux-tdep.c
+++ b/gdb/ppc-linux-tdep.c
@@ -47,6 +47,7 @@
#include "exceptions.h"
#include "arch-utils.h"
#include "spu-tdep.h"
+#include "xml-syscall.h"
#include "features/rs6000/powerpc-32l.c"
#include "features/rs6000/powerpc-altivec32l.c"
@@ -64,6 +65,9 @@
#include "features/rs6000/powerpc-isa205-vsx64l.c"
#include "features/rs6000/powerpc-e500l.c"
+/* The syscall's XML filename for PPC and PPC64. */
+#define XML_SYSCALL_FILENAME_PPC "syscalls/ppc-linux.xml"
+#define XML_SYSCALL_FILENAME_PPC64 "syscalls/ppc64-linux.xml"
/* ppc_linux_memory_remove_breakpoints attempts to remove a breakpoint
in much the same fashion as memory_remove_breakpoint in mem-break.c,
@@ -1066,6 +1070,39 @@ ppc_linux_trap_reg_p (struct gdbarch *gdbarch)
&& register_size (gdbarch, PPC_TRAP_REGNUM) > 0;
}
+/* Return the current system call's number present in the
+ r0 register. When the function fails, it returns -1. */
+static LONGEST
+ppc_linux_get_syscall_number (struct gdbarch *gdbarch,
+ ptid_t ptid)
+{
+ struct regcache *regcache = get_thread_regcache (ptid);
+ struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
+ enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
+ struct cleanup *cleanbuf;
+ /* The content of a register */
+ gdb_byte *buf;
+ /* The result */
+ LONGEST ret;
+
+ /* Make sure we're in a 32- or 64-bit machine */
+ gdb_assert (tdep->wordsize == 4 || tdep->wordsize == 8);
+
+ buf = (gdb_byte *) xmalloc (tdep->wordsize * sizeof (gdb_byte));
+
+ cleanbuf = make_cleanup (xfree, buf);
+
+ /* Getting the system call number from the register.
+ When dealing with PowerPC architecture, this information
+ is stored at 0th register. */
+ regcache_cooked_read (regcache, tdep->ppc_gp0_regnum, buf);
+
+ ret = extract_signed_integer (buf, tdep->wordsize, byte_order);
+ do_cleanups (cleanbuf);
+
+ return ret;
+}
+
static void
ppc_linux_write_pc (struct regcache *regcache, CORE_ADDR pc)
{
@@ -1435,6 +1472,9 @@ ppc_linux_init_abi (struct gdbarch_info info,
/* Handle inferior calls during interrupted system calls. */
set_gdbarch_write_pc (gdbarch, ppc_linux_write_pc);
+ /* Get the syscall number from the arch's register. */
+ set_gdbarch_get_syscall_number (gdbarch, ppc_linux_get_syscall_number);
+
if (tdep->wordsize == 4)
{
/* Until November 2001, gcc did not comply with the 32 bit SysV
@@ -1454,6 +1494,9 @@ ppc_linux_init_abi (struct gdbarch_info info,
set_solib_svr4_fetch_link_map_offsets
(gdbarch, svr4_ilp32_fetch_link_map_offsets);
+ /* Setting the correct XML syscall filename. */
+ set_xml_syscall_file_name (XML_SYSCALL_FILENAME_PPC);
+
/* Trampolines. */
tramp_frame_prepend_unwinder (gdbarch, &ppc32_linux_sigaction_tramp_frame);
tramp_frame_prepend_unwinder (gdbarch, &ppc32_linux_sighandler_tramp_frame);
@@ -1477,6 +1520,9 @@ ppc_linux_init_abi (struct gdbarch_info info,
set_solib_svr4_fetch_link_map_offsets
(gdbarch, svr4_lp64_fetch_link_map_offsets);
+ /* Setting the correct XML syscall filename. */
+ set_xml_syscall_file_name (XML_SYSCALL_FILENAME_PPC64);
+
/* Trampolines. */
tramp_frame_prepend_unwinder (gdbarch, &ppc64_linux_sigaction_tramp_frame);
tramp_frame_prepend_unwinder (gdbarch, &ppc64_linux_sighandler_tramp_frame);
diff --git a/gdb/target.c b/gdb/target.c
index a662eca..73226e9 100644
--- a/gdb/target.c
+++ b/gdb/target.c
@@ -647,6 +647,7 @@ update_current_target (void)
/* Do not inherit to_follow_fork. */
INHERIT (to_insert_exec_catchpoint, t);
INHERIT (to_remove_exec_catchpoint, t);
+ INHERIT (to_set_syscall_catchpoint, t);
INHERIT (to_has_exited, t);
/* Do not inherit to_mourn_inferiour. */
INHERIT (to_can_run, t);
@@ -789,6 +790,9 @@ update_current_target (void)
de_fault (to_remove_exec_catchpoint,
(int (*) (int))
tcomplain);
+ de_fault (to_set_syscall_catchpoint,
+ (int (*) (int, int, int, int, int *))
+ tcomplain);
de_fault (to_has_exited,
(int (*) (int, int, int *))
return_zero);
@@ -2865,9 +2869,9 @@ target_waitstatus_to_string (const struct target_waitstatus *ws)
case TARGET_WAITKIND_EXECD:
return xstrprintf ("%sexecd", kind_str);
case TARGET_WAITKIND_SYSCALL_ENTRY:
- return xstrprintf ("%ssyscall-entry", kind_str);
+ return xstrprintf ("%sentered syscall", kind_str);
case TARGET_WAITKIND_SYSCALL_RETURN:
- return xstrprintf ("%ssyscall-return", kind_str);
+ return xstrprintf ("%sexited syscall", kind_str);
case TARGET_WAITKIND_SPURIOUS:
return xstrprintf ("%sspurious", kind_str);
case TARGET_WAITKIND_IGNORE:
diff --git a/gdb/target.h b/gdb/target.h
index c210fea..b1cb852 100644
--- a/gdb/target.h
+++ b/gdb/target.h
@@ -142,14 +142,15 @@ struct target_waitstatus
{
enum target_waitkind kind;
- /* Forked child pid, execd pathname, exit status or signal number. */
+ /* Forked child pid, execd pathname, exit status, signal number or
+ syscall number. */
union
{
int integer;
enum target_signal sig;
ptid_t related_pid;
char *execd_pathname;
- int syscall_id;
+ int syscall_number;
}
value;
};
@@ -161,6 +162,21 @@ struct target_waitstatus
event. */
#define TARGET_WNOHANG 1
+/* The structure below stores information about a system call.
+ It is basically used in the "catch syscall" command, and in
+ every function that gives information about a system call.
+
+ It's also good to mention that its fields represent everything
+ that we currently know about a syscall in GDB. */
+struct syscall
+ {
+ /* The syscall number. */
+ int number;
+
+ /* The syscall name. */
+ const char *name;
+ };
+
/* Return a pretty printed form of target_waitstatus.
Space for the result is malloc'd, caller must free. */
extern char *target_waitstatus_to_string (const struct target_waitstatus *);
@@ -406,6 +422,7 @@ struct target_ops
int (*to_follow_fork) (struct target_ops *, int);
void (*to_insert_exec_catchpoint) (int);
int (*to_remove_exec_catchpoint) (int);
+ int (*to_set_syscall_catchpoint) (int, int, int, int, int *);
int (*to_has_exited) (int, int, int *);
void (*to_mourn_inferior) (struct target_ops *);
int (*to_can_run) (void);
@@ -748,6 +765,8 @@ extern int inferior_has_vforked (ptid_t pid, ptid_t *child_pid);
extern int inferior_has_execd (ptid_t pid, char **execd_pathname);
+extern int inferior_has_called_syscall (ptid_t pid, int *syscall_number);
+
/* Print a line about the current target. */
#define target_files_info() \
@@ -900,6 +919,27 @@ int target_follow_fork (int follow_child);
#define target_remove_exec_catchpoint(pid) \
(*current_target.to_remove_exec_catchpoint) (pid)
+/* Syscall catch.
+
+ NEEDED is nonzero if any syscall catch (of any kind) is requested.
+ If NEEDED is zero, it means the target can disable the mechanism to
+ catch system calls because there are no more catchpoints of this type.
+
+ ANY_COUNT is nonzero if a generic (filter-less) syscall catch is
+ being requested. In this case, both TABLE_SIZE and TABLE should
+ be ignored.
+
+ TABLE_SIZE is the number of elements in TABLE. It only matters if
+ ANY_COUNT is zero.
+
+ TABLE is an array of ints, indexed by syscall number. An element in
+ this array is nonzero if that syscall should be caught. This argument
+ only matters if ANY_COUNT is zero. */
+
+#define target_set_syscall_catchpoint(pid, needed, any_count, table_size, table) \
+ (*current_target.to_set_syscall_catchpoint) (pid, needed, any_count, \
+ table_size, table)
+
/* Returns TRUE if PID has exited. And, also sets EXIT_STATUS to the
exit code of PID, if any. */
diff --git a/gdb/xml-support.c b/gdb/xml-support.c
index 937c6c3..ad20d3b 100644
--- a/gdb/xml-support.c
+++ b/gdb/xml-support.c
@@ -1036,6 +1036,66 @@ obstack_xml_printf (struct obstack *obstack, const char *format, ...)
va_end (ap);
}
+char *
+xml_fetch_content_from_file (const char *filename, void *baton)
+{
+ const char *dirname = baton;
+ FILE *file;
+ struct cleanup *back_to;
+ char *text;
+ size_t len, offset;
+
+ if (dirname && *dirname)
+ {
+ char *fullname = concat (dirname, "/", filename, (char *) NULL);
+ if (fullname == NULL)
+ nomem (0);
+ file = fopen (fullname, FOPEN_RT);
+ xfree (fullname);
+ }
+ else
+ file = fopen (filename, FOPEN_RT);
+
+ if (file == NULL)
+ return NULL;
+
+ back_to = make_cleanup_fclose (file);
+
+ /* Read in the whole file, one chunk at a time. */
+ len = 4096;
+ offset = 0;
+ text = xmalloc (len);
+ make_cleanup (free_current_contents, &text);
+ while (1)
+ {
+ size_t bytes_read;
+
+ /* Continue reading where the last read left off. Leave at least
+ one byte so that we can NUL-terminate the result. */
+ bytes_read = fread (text + offset, 1, len - offset - 1, file);
+ if (ferror (file))
+ {
+ warning (_("Read error from \"%s\""), filename);
+ do_cleanups (back_to);
+ return NULL;
+ }
+
+ offset += bytes_read;
+
+ if (feof (file))
+ break;
+
+ len = len * 2;
+ text = xrealloc (text, len);
+ }
+
+ fclose (file);
+ discard_cleanups (back_to);
+
+ text[offset] = '\0';
+ return text;
+}
+
void _initialize_xml_support (void);
void
diff --git a/gdb/xml-support.h b/gdb/xml-support.h
index d6105f7..135263d 100644
--- a/gdb/xml-support.h
+++ b/gdb/xml-support.h
@@ -240,4 +240,10 @@ extern void obstack_xml_printf (struct obstack *obstack,
const char *format, ...)
ATTRIBUTE_PRINTF_2;
+/* Open FILENAME, read all its text into memory, close it, and return
+ the text. If something goes wrong, return NULL and warn. */
+
+extern char *xml_fetch_content_from_file (const char *filename,
+ void *baton);
+
#endif
diff --git a/gdb/xml-tdesc.c b/gdb/xml-tdesc.c
index 4fa7843..102049f 100644
--- a/gdb/xml-tdesc.c
+++ b/gdb/xml-tdesc.c
@@ -426,69 +426,6 @@ tdesc_parse_xml (const char *document, xml_fetch_another fetcher,
#endif /* HAVE_LIBEXPAT */
-/* Open FILENAME, read all its text into memory, close it, and return
- the text. If something goes wrong, return NULL and warn. */
-
-static char *
-fetch_xml_from_file (const char *filename, void *baton)
-{
- const char *dirname = baton;
- FILE *file;
- struct cleanup *back_to;
- char *text;
- size_t len, offset;
-
- if (dirname && *dirname)
- {
- char *fullname = concat (dirname, "/", filename, (char *) NULL);
- if (fullname == NULL)
- nomem (0);
- file = fopen (fullname, FOPEN_RT);
- xfree (fullname);
- }
- else
- file = fopen (filename, FOPEN_RT);
-
- if (file == NULL)
- return NULL;
-
- back_to = make_cleanup_fclose (file);
-
- /* Read in the whole file, one chunk at a time. */
- len = 4096;
- offset = 0;
- text = xmalloc (len);
- make_cleanup (free_current_contents, &text);
- while (1)
- {
- size_t bytes_read;
-
- /* Continue reading where the last read left off. Leave at least
- one byte so that we can NUL-terminate the result. */
- bytes_read = fread (text + offset, 1, len - offset - 1, file);
- if (ferror (file))
- {
- warning (_("Read error from \"%s\""), filename);
- do_cleanups (back_to);
- return NULL;
- }
-
- offset += bytes_read;
-
- if (feof (file))
- break;
-
- len = len * 2;
- text = xrealloc (text, len);
- }
-
- fclose (file);
- discard_cleanups (back_to);
-
- text[offset] = '\0';
- return text;
-}
-
/* Read an XML target description from FILENAME. Parse it, and return
the parsed description. */
@@ -500,7 +437,7 @@ file_read_description_xml (const char *filename)
struct cleanup *back_to;
char *dirname;
- tdesc_str = fetch_xml_from_file (filename, NULL);
+ tdesc_str = xml_fetch_content_from_file (filename, NULL);
if (tdesc_str == NULL)
{
warning (_("Could not open \"%s\""), filename);
@@ -513,7 +450,7 @@ file_read_description_xml (const char *filename)
if (dirname != NULL)
make_cleanup (xfree, dirname);
- tdesc = tdesc_parse_xml (tdesc_str, fetch_xml_from_file, dirname);
+ tdesc = tdesc_parse_xml (tdesc_str, xml_fetch_content_from_file, dirname);
do_cleanups (back_to);
return tdesc;