static ptid_t do_attach (ptid_t ptid);
static void do_detach (int signo);
static int register_gdb_signals (procinfo *, gdb_sigset_t *);
+static void proc_trace_syscalls_1 (procinfo *pi, int syscallnum,
+ int entry_or_exit, int mode, int from_tty);
+static int insert_dbx_link_breakpoint (procinfo *pi);
+static void remove_dbx_link_breakpoint (void);
+
+/* On mips-irix, we need to insert a breakpoint at __dbx_link during
+ the startup phase. The following two variables are used to record
+ the address of the breakpoint, and the code that was replaced by
+ a breakpoint. */
+static int dbx_link_bpt_addr = 0;
+static char dbx_link_shadow_contents[BREAKPOINT_MAX];
/*
* Function: procfs_debug_inferior
address. */
wstat = (SIGTRAP << 8) | 0177;
}
+#ifdef SYS_syssgi
+ else if (what == SYS_syssgi)
+ {
+ /* see if we can break on dbx_link(). If yes, then
+ we no longer need the SYS_syssgi notifications. */
+ if (insert_dbx_link_breakpoint (pi))
+ proc_trace_syscalls_1 (pi, SYS_syssgi, PR_SYSEXIT,
+ FLAG_RESET, 0);
+
+ /* This is an internal event and should be transparent
+ to wfi, so resume the execution and wait again. See
+ comment in procfs_init_inferior() for more details. */
+ target_resume (ptid, 0, TARGET_SIGNAL_0);
+ goto wait_again;
+ }
+#endif
else if (syscall_is_lwp_create (pi, what))
{
/*
#if (FLTTRACE != FLTBPT) /* avoid "duplicate case" error */
case FLTTRACE:
#endif
+ /* If we hit our __dbx_link() internal breakpoint,
+ then remove it. See comments in procfs_init_inferior()
+ for more details. */
+ if (dbx_link_bpt_addr != 0
+ && dbx_link_bpt_addr == read_pc ())
+ remove_dbx_link_breakpoint ();
+
wstat = (SIGTRAP << 8) | 0177;
break;
case FLTSTACK:
/* Typically two, one trap to exec the shell, one to exec the
program being debugged. Defined by "inferior.h". */
startup_inferior (START_INFERIOR_TRAPS_EXPECTED);
+
+#ifdef SYS_syssgi
+ /* On mips-irix, we need to stop the inferior early enough during
+ the startup phase in order to be able to load the shared library
+ symbols and insert the breakpoints that are located in these shared
+ libraries. Stopping at the program entry point is not good enough
+ because the -init code is executed before the execution reaches
+ that point.
+
+ So what we need to do is to insert a breakpoint in the runtime
+ loader (rld), more precisely in __dbx_link(). This procedure is
+ called by rld once all shared libraries have been mapped, but before
+ the -init code is executed. Unfortuantely, this is not straightforward,
+ as rld is not part of the executable we are running, and thus we need
+ the inferior to run until rld itself has been mapped in memory.
+
+ For this, we trace all syssgi() syscall exit events. Each time
+ we detect such an event, we iterate over each text memory maps,
+ get its associated fd, and scan the symbol table for __dbx_link().
+ When found, we know that rld has been mapped, and that we can insert
+ the breakpoint at the symbol address. Once the dbx_link() breakpoint
+ has been inserted, the syssgi() notifications are no longer necessary,
+ so they should be canceled. */
+ proc_trace_syscalls_1 (pi, SYS_syssgi, PR_SYSEXIT, FLAG_SET, 0);
+ dbx_link_bpt_addr = 0;
+#endif
}
/*
fork_inferior (exec_file, allargs, env, procfs_set_exec_trap,
procfs_init_inferior, NULL, shell_file);
+#ifdef SYS_syssgi
+ /* Make sure to cancel the syssgi() syscall-exit notifications.
+ They should normally have been removed by now, but they may still
+ be activated if the inferior doesn't use shared libraries, or if
+ we didn't locate __dbx_link, or if we never stopped in __dbx_link.
+ See procfs_init_inferior() for more details. */
+ proc_trace_syscalls_1 (find_procinfo_or_die (PIDGET (inferior_ptid), 0),
+ SYS_syssgi, PR_SYSEXIT, FLAG_RESET, 0);
+#endif
+
/* We are at the first instruction we care about. */
/* Pedal to the metal... */
find_memory_regions_callback);
}
+/* Remove the breakpoint that we inserted in __dbx_link().
+ Does nothing if the breakpoint hasn't been inserted or has already
+ been removed. */
+
+static void
+remove_dbx_link_breakpoint (void)
+{
+ if (dbx_link_bpt_addr == 0)
+ return;
+
+ if (memory_remove_breakpoint (dbx_link_bpt_addr,
+ dbx_link_shadow_contents) != 0)
+ warning ("Unable to remove __dbx_link breakpoint.");
+
+ dbx_link_bpt_addr = 0;
+}
+
+/* Return the address of the __dbx_link() function in the file
+ refernced by ABFD by scanning its symbol table. Return 0 if
+ the symbol was not found. */
+
+static CORE_ADDR
+dbx_link_addr (bfd *abfd)
+{
+ long storage_needed;
+ asymbol **symbol_table;
+ long number_of_symbols;
+ long i;
+
+ storage_needed = bfd_get_symtab_upper_bound (abfd);
+ if (storage_needed <= 0)
+ return 0;
+
+ symbol_table = (asymbol **) xmalloc (storage_needed);
+ make_cleanup (xfree, symbol_table);
+
+ number_of_symbols = bfd_canonicalize_symtab (abfd, symbol_table);
+
+ for (i = 0; i < number_of_symbols; i++)
+ {
+ asymbol *sym = symbol_table[i];
+
+ if ((sym->flags & BSF_GLOBAL)
+ && sym->name != NULL && strcmp (sym->name, "__dbx_link") == 0)
+ return (sym->value + sym->section->vma);
+ }
+
+ /* Symbol not found, return NULL. */
+ return 0;
+}
+
+/* Search the symbol table of the file referenced by FD for a symbol
+ named __dbx_link(). If found, then insert a breakpoint at this location,
+ and return nonzero. Return zero otherwise. */
+
+static int
+insert_dbx_link_bpt_in_file (int fd, CORE_ADDR ignored)
+{
+ bfd *abfd;
+ long storage_needed;
+ CORE_ADDR sym_addr;
+
+ abfd = bfd_fdopenr ("unamed", 0, fd);
+ if (abfd == NULL)
+ {
+ warning ("Failed to create a bfd: %s.\n", bfd_errmsg (bfd_get_error ()));
+ return 0;
+ }
+
+ if (!bfd_check_format (abfd, bfd_object))
+ {
+ /* Not the correct format, so we can not possibly find the dbx_link
+ symbol in it. */
+ bfd_close (abfd);
+ return 0;
+ }
+
+ sym_addr = dbx_link_addr (abfd);
+ if (sym_addr != 0)
+ {
+ /* Insert the breakpoint. */
+ dbx_link_bpt_addr = sym_addr;
+ if (target_insert_breakpoint (sym_addr, dbx_link_shadow_contents) != 0)
+ {
+ warning ("Failed to insert dbx_link breakpoint.");
+ bfd_close (abfd);
+ return 0;
+ }
+ bfd_close (abfd);
+ return 1;
+ }
+
+ bfd_close (abfd);
+ return 0;
+}
+
+/* If the given memory region MAP contains a symbol named __dbx_link,
+ insert a breakpoint at this location and return nonzero. Return
+ zero otherwise. */
+
+static int
+insert_dbx_link_bpt_in_region (struct prmap *map,
+ int (*child_func) (),
+ void *data)
+{
+ procinfo *pi = (procinfo *) data;
+
+ /* We know the symbol we're looking for is in a text region, so
+ only look for it if the region is a text one. */
+ if (map->pr_mflags & MA_EXEC)
+ return solib_mappings_callback (map, insert_dbx_link_bpt_in_file, pi);
+
+ return 0;
+}
+
+/* Search all memory regions for a symbol named __dbx_link. If found,
+ insert a breakpoint at its location, and return nonzero. Return zero
+ otherwise. */
+
+static int
+insert_dbx_link_breakpoint (procinfo *pi)
+{
+ return iterate_over_mappings (pi, NULL, pi, insert_dbx_link_bpt_in_region);
+}
+
/*
* Function: mappingflags
*
do_cleanups (old_chain);
}
+/* Modify the status of the system call identified by SYSCALLNUM in
+ the set of syscalls that are currently traced/debugged.
+
+ If ENTRY_OR_EXIT is set to PR_SYSENTRY, then the entry syscalls set
+ will be updated. Otherwise, the exit syscalls set will be updated.
+
+ If MODE is FLAG_SET, then traces will be enabled. Otherwise, they
+ will be disabled. */
+
+static void
+proc_trace_syscalls_1 (procinfo *pi, int syscallnum, int entry_or_exit,
+ int mode, int from_tty)
+{
+ sysset_t *sysset;
+
+ if (entry_or_exit == PR_SYSENTRY)
+ sysset = proc_get_traced_sysentry (pi, NULL);
+ else
+ sysset = proc_get_traced_sysexit (pi, NULL);
+
+ if (sysset == NULL)
+ proc_error (pi, "proc-trace, get_traced_sysset", __LINE__);
+
+ if (mode == FLAG_SET)
+ gdb_praddsysset (sysset, syscallnum);
+ else
+ gdb_prdelsysset (sysset, syscallnum);
+
+ if (entry_or_exit == PR_SYSENTRY)
+ {
+ if (!proc_set_traced_sysentry (pi, sysset))
+ proc_error (pi, "proc-trace, set_traced_sysentry", __LINE__);
+ }
+ else
+ {
+ if (!proc_set_traced_sysexit (pi, sysset))
+ proc_error (pi, "proc-trace, set_traced_sysexit", __LINE__);
+ }
+}
+
static void
proc_trace_syscalls (char *args, int from_tty, int entry_or_exit, int mode)
{
procinfo *pi;
- sysset_t *sysset;
- int syscallnum = 0;
if (PIDGET (inferior_ptid) <= 0)
error ("you must be debugging a process to use this command.");
pi = find_procinfo_or_die (PIDGET (inferior_ptid), 0);
if (isdigit (args[0]))
{
- syscallnum = atoi (args);
- if (entry_or_exit == PR_SYSENTRY)
- sysset = proc_get_traced_sysentry (pi, NULL);
- else
- sysset = proc_get_traced_sysexit (pi, NULL);
-
- if (sysset == NULL)
- proc_error (pi, "proc-trace, get_traced_sysset", __LINE__);
-
- if (mode == FLAG_SET)
- gdb_praddsysset (sysset, syscallnum);
- else
- gdb_prdelsysset (sysset, syscallnum);
+ const int syscallnum = atoi (args);
- if (entry_or_exit == PR_SYSENTRY)
- {
- if (!proc_set_traced_sysentry (pi, sysset))
- proc_error (pi, "proc-trace, set_traced_sysentry", __LINE__);
- }
- else
- {
- if (!proc_set_traced_sysexit (pi, sysset))
- proc_error (pi, "proc-trace, set_traced_sysexit", __LINE__);
- }
+ proc_trace_syscalls_1 (pi, syscallnum, entry_or_exit, mode, from_tty);
}
}
projects / binutils-gdb.git / commitdiff