From 9ee23a853c18da3c83530c7957464bc6b6e9fb16 Mon Sep 17 00:00:00 2001 From: Markus Metzger Date: Fri, 19 Jan 2018 09:41:42 +0100 Subject: [PATCH] btrace, gdbserver: use exceptions to convey btrace enable/disable errors Change error reporting to use exceptions and be prepared to catch them in gdbserver. We use the exception message in our error reply to GDB. This may remove some detail from the error message in the native case since errno is no longer printed. Later patches will improve that. We're still using error strings on the RSP level. This patch does not affect the interoperability of older/newer GDB/gdbserver. gdbserver/ * server.c (handle_btrace_enable_bts, handle_btrace_enable_pt) (handle_btrace_disable): Change return type to void. Use exceptions to report errors. (handle_btrace_general_set): Catch exception and copy message to return message. gdb/ * nat/linux-btrace.c (linux_enable_btrace): Throw exception if enabling btrace failed. * x86-linux-nat.c (x86_linux_enable_btrace): Catch btrace enabling exception and use message in own exception. --- gdb/ChangeLog | 7 ++++++ gdb/gdbserver/ChangeLog | 8 ++++++ gdb/gdbserver/server.c | 55 ++++++++++++++++++----------------------- gdb/nat/linux-btrace.c | 3 +++ gdb/x86-linux-nat.c | 19 ++++++++------ 5 files changed, 53 insertions(+), 39 deletions(-) diff --git a/gdb/ChangeLog b/gdb/ChangeLog index 31d533433f7..3ff2ccf7c5c 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,3 +1,10 @@ +2018-02-09 Markus Metzger + + * nat/linux-btrace.c (linux_enable_btrace): Throw exception if enabling + btrace failed. + * x86-linux-nat.c (x86_linux_enable_btrace): Catch btrace enabling + exception and use message in own exception. + 2018-02-09 Markus Metzger * nat/linux-btrace.c: Include scoped_fd.h and scoped_mmap.h. diff --git a/gdb/gdbserver/ChangeLog b/gdb/gdbserver/ChangeLog index b80d82058ea..1b8d6f6276c 100644 --- a/gdb/gdbserver/ChangeLog +++ b/gdb/gdbserver/ChangeLog @@ -1,3 +1,11 @@ +2018-02-09 Markus Metzger + + * server.c (handle_btrace_enable_bts, handle_btrace_enable_pt) + (handle_btrace_disable): Change return type to void. Use exceptions + to report errors. + (handle_btrace_general_set): Catch exception and copy message to + return message. + 2018-02-08 Tom Tromey * linux-low.c (install_software_single_step_breakpoints): Use diff --git a/gdb/gdbserver/server.c b/gdb/gdbserver/server.c index 9d12ce6f706..5ce62810bf6 100644 --- a/gdb/gdbserver/server.c +++ b/gdb/gdbserver/server.c @@ -380,50 +380,41 @@ write_qxfer_response (char *buf, const gdb_byte *data, int len, int is_more) /* Handle btrace enabling in BTS format. */ -static const char * +static void handle_btrace_enable_bts (struct thread_info *thread) { if (thread->btrace != NULL) - return "E.Btrace already enabled."; + error (_("Btrace already enabled.")); current_btrace_conf.format = BTRACE_FORMAT_BTS; thread->btrace = target_enable_btrace (thread->id, ¤t_btrace_conf); - if (thread->btrace == NULL) - return "E.Could not enable btrace."; - - return NULL; } /* Handle btrace enabling in Intel Processor Trace format. */ -static const char * +static void handle_btrace_enable_pt (struct thread_info *thread) { if (thread->btrace != NULL) - return "E.Btrace already enabled."; + error (_("Btrace already enabled.")); current_btrace_conf.format = BTRACE_FORMAT_PT; thread->btrace = target_enable_btrace (thread->id, ¤t_btrace_conf); - if (thread->btrace == NULL) - return "E.Could not enable btrace."; - - return NULL; } /* Handle btrace disabling. */ -static const char * +static void handle_btrace_disable (struct thread_info *thread) { if (thread->btrace == NULL) - return "E.Branch tracing not enabled."; + error (_("Branch tracing not enabled.")); if (target_disable_btrace (thread->btrace) != 0) - return "E.Could not disable branch tracing."; + error (_("Could not disable branch tracing.")); thread->btrace = NULL; - return NULL; } /* Handle the "Qbtrace" packet. */ @@ -432,7 +423,6 @@ static int handle_btrace_general_set (char *own_buf) { struct thread_info *thread; - const char *err; char *op; if (!startswith (own_buf, "Qbtrace:")) @@ -454,21 +444,24 @@ handle_btrace_general_set (char *own_buf) return -1; } - err = NULL; - - if (strcmp (op, "bts") == 0) - err = handle_btrace_enable_bts (thread); - else if (strcmp (op, "pt") == 0) - err = handle_btrace_enable_pt (thread); - else if (strcmp (op, "off") == 0) - err = handle_btrace_disable (thread); - else - err = "E.Bad Qbtrace operation. Use bts, pt, or off."; + TRY + { + if (strcmp (op, "bts") == 0) + handle_btrace_enable_bts (thread); + else if (strcmp (op, "pt") == 0) + handle_btrace_enable_pt (thread); + else if (strcmp (op, "off") == 0) + handle_btrace_disable (thread); + else + error (_("Bad Qbtrace operation. Use bts, pt, or off.")); - if (err != 0) - strcpy (own_buf, err); - else - write_ok (own_buf); + write_ok (own_buf); + } + CATCH (exception, RETURN_MASK_ERROR) + { + sprintf (own_buf, "E.%s", exception.message); + } + END_CATCH return 1; } diff --git a/gdb/nat/linux-btrace.c b/gdb/nat/linux-btrace.c index 354094f6cfd..2b37e419ce7 100644 --- a/gdb/nat/linux-btrace.c +++ b/gdb/nat/linux-btrace.c @@ -909,6 +909,9 @@ linux_enable_btrace (ptid_t ptid, const struct btrace_config *conf) break; } + if (tinfo == NULL) + error (_("Unknown error.")); + return tinfo; } diff --git a/gdb/x86-linux-nat.c b/gdb/x86-linux-nat.c index 46bb6a4dca7..75f68de9c2d 100644 --- a/gdb/x86-linux-nat.c +++ b/gdb/x86-linux-nat.c @@ -216,14 +216,17 @@ static struct btrace_target_info * x86_linux_enable_btrace (struct target_ops *self, ptid_t ptid, const struct btrace_config *conf) { - struct btrace_target_info *tinfo; - - errno = 0; - tinfo = linux_enable_btrace (ptid, conf); - - if (tinfo == NULL) - error (_("Could not enable branch tracing for %s: %s."), - target_pid_to_str (ptid), safe_strerror (errno)); + struct btrace_target_info *tinfo = nullptr; + TRY + { + tinfo = linux_enable_btrace (ptid, conf); + } + CATCH (exception, RETURN_MASK_ERROR) + { + error (_("Could not enable branch tracing for %s: %s"), + target_pid_to_str (ptid), exception.message); + } + END_CATCH return tinfo; } -- 2.30.2