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| author | Tom Tromey <tromey@adacore.com> | 2022-03-31 07:55:09 -0600 |
|---|---|---|
| committer | Tom Tromey <tromey@adacore.com> | 2022-04-14 09:56:26 -0600 |
| commit | 7ae6857316e020467f84645ba7c1c5ec6c085bd9 (patch) | |
| tree | f82b19ec5928fcb7bd197f03d70dceb4071c49b4 /gdb | |
| parent | 77d97a0a19033a45fc7e691078c90718f9f5d5e5 (diff) | |
| download | gdb-7ae6857316e020467f84645ba7c1c5ec6c085bd9.zip gdb-7ae6857316e020467f84645ba7c1c5ec6c085bd9.tar.gz gdb-7ae6857316e020467f84645ba7c1c5ec6c085bd9.tar.bz2 | |
Fix regression on Windows with WOW64
Internally at AdaCore, we recently started testing a 64-bit gdb
debugging 32-bit processes. This failed with gdb head, but not with
gdb 11.
The tests fail like this:
Starting program: [...].exe
warning: Could not load shared library symbols for WOW64_IMAGE_SECTION.
Do you need "set solib-search-path" or "set sysroot"?
warning: Could not load shared library symbols for WOW64_IMAGE_SECTION.
Do you need "set solib-search-path" or "set sysroot"?
warning: Could not load shared library symbols for NOT_AN_IMAGE.
Do you need "set solib-search-path" or "set sysroot"?
warning: Could not load shared library symbols for NOT_AN_IMAGE.
Do you need "set solib-search-path" or "set sysroot"?
After some debugging and bisecting, to my surprise the bug was
introduced by commit 183be222 ("gdb, gdbserver: make target_waitstatus
safe").
The problem occurs in handle_exception. Previously the code did:
- ourstatus->kind = TARGET_WAITKIND_STOPPED;
[...]
case EXCEPTION_BREAKPOINT:
[...]
- ourstatus->kind = TARGET_WAITKIND_SPURIOUS;
[...]
/* FALLTHROUGH */
case STATUS_WX86_BREAKPOINT:
DEBUG_EXCEPTION_SIMPLE ("EXCEPTION_BREAKPOINT");
- ourstatus->value.sig = GDB_SIGNAL_TRAP;
[...]
- last_sig = ourstatus->value.sig;
However, in the new code, the fallthrough case does:
+ ourstatus->set_stopped (GDB_SIGNAL_TRAP);
... which changes the 'kind' in 'ourstatus' after falling through.
This patch rearranges the 'last_sig' setting to more closely match
what was done before (this is probably not strictly needed but also
seemed harmless), and removes the fall-through in the
'ignore_first_breakpoint' case when __x86_64__ is defined.
Diffstat (limited to 'gdb')
| -rw-r--r-- | gdb/nat/windows-nat.c | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/gdb/nat/windows-nat.c b/gdb/nat/windows-nat.c index c890ee1..2e4c482 100644 --- a/gdb/nat/windows-nat.c +++ b/gdb/nat/windows-nat.c @@ -183,6 +183,8 @@ windows_process_info::handle_exception (struct target_waitstatus *ourstatus, thread_rec (ptid_t (current_event.dwProcessId, current_event.dwThreadId, 0), DONT_SUSPEND); + last_sig = GDB_SIGNAL_0; + switch (code) { case EXCEPTION_ACCESS_VIOLATION: @@ -243,8 +245,10 @@ windows_process_info::handle_exception (struct target_waitstatus *ourstatus, on startup, first a BREAKPOINT for the 64bit ntdll.dll, then a WX86_BREAKPOINT for the 32bit ntdll.dll. Here we only care about the WX86_BREAKPOINT's. */ + DEBUG_EXCEPTION_SIMPLE ("EXCEPTION_BREAKPOINT - ignore_first_breakpoint"); ourstatus->set_spurious (); ignore_first_breakpoint = false; + break; } else if (wow64_process) { @@ -255,7 +259,7 @@ windows_process_info::handle_exception (struct target_waitstatus *ourstatus, gdb lets the target process continue. So handle it as SIGINT instead, then the target is stopped unconditionally. */ - DEBUG_EXCEPTION_SIMPLE ("EXCEPTION_BREAKPOINT"); + DEBUG_EXCEPTION_SIMPLE ("EXCEPTION_BREAKPOINT - wow64_process"); rec->ExceptionCode = DBG_CONTROL_C; ourstatus->set_stopped (GDB_SIGNAL_INT); break; |