Commit Graph

17 Commits

Author SHA1 Message Date
Michał Górny 8666b9057f [lldb] [POSIX-DYLD] Add libraries from initial rendezvous brkpt hit
Explicitly consider the libraries reported on the initial rendezvous
breakpoint hit added.  This is necessary on FreeBSD since the dynamic
loader issues only a single 'consistent' state rendezvous breakpoint hit
for all the libraries present in DT_NEEDED.  It is also helpful on Linux
where it ensures that ld-linux is considered loaded as well
as the shared system libraries reported afterwards.

Reenable memory maps on FreeBSD since this fixed the issue triggered
by them.

Differential Revision: https://reviews.llvm.org/D92187
2020-12-17 09:31:10 +01:00
Michał Górny 733e2ae8cd Revert "[lldb] [POSIX-DYLD] Add libraries from initial eTakeSnapshot action"
This reverts commit 09b08833f3.

This code is wrong on Linux, and causes ld-linux and linux-vdso to be
reported twice.  I need to work on it more.
2020-12-07 15:58:49 +01:00
Michał Górny 276638ecaf [lldb] [Process/FreeBSDRemote] Implement GetLoadedModuleFileSpec() and GetFileLoadAddress()
Copy the Linux implementation of GetLoadedModuleFileSpec()
and GetFileLoadAddress() into NativeProcessFreeBSD.  This does not seem
to change anything at the moment but reducing the differences between
the plugins should help us in the long term.

Differential Revision: https://reviews.llvm.org/D92314
2020-12-07 09:56:51 +01:00
Michał Górny 09b08833f3 [lldb] [POSIX-DYLD] Add libraries from initial eTakeSnapshot action
Explicitly consider the libraries reported on the initial eTakeSnapshot
action added, through adding them to the added soentry list
in DYLDRendezvous::SaveSOEntriesFromRemote().  This is necessary
on FreeBSD since the dynamic loader issues only a single 'consistent'
state rendezvous breakpoint hit for all the libraries present
in DT_NEEDED (while Linux issues an added-consistent event pair).

Reenable memory maps on FreeBSD since this fixed the issue triggered
by them.

Differential Revision: https://reviews.llvm.org/D92187
2020-12-07 09:56:51 +01:00
Michał Górny 4c54399b7e [lldb] [Process/FreeBSDRemote] Explicitly copy dbregs to new threads
Explicitly copy dbregs to new threads to ensure that watchpoints
are propagated properly.  Fixes the test failure due to apparent kernel
race between reporting a new thread and resuming main thread execution
that makes implicit inheritance of dbregs unreliable.  By copying them
explicitly, we ensure that the new thread correctly respects watchpoints
that were set after the thread was created but before it was reported.

The code is copied from the NetBSD plugin and modernized to use
llvm::Error.

Differential Revision: https://reviews.llvm.org/D91032
2020-11-10 14:18:03 +01:00
Michał Górny e637602e7a [lldb] [Process/FreeBSDRemote] Fix handling user-generated SIGTRAP
Update the SIGTRAP handler to account for the possibility of SIGTRAP
being generated by the user, i.e. not having any specific debugging
event associated with it, as well as receiving unknown SIGTRAPs.  These
instances of SIGTRAP are passed to the regular signal handler.

Differential Revision: https://reviews.llvm.org/D91007
2020-11-10 14:18:03 +01:00
Michał Górny 9e1409aa1e [lldb] [Process/FreeBSDRemote] Handle exec() from inferior
Differential Revision: https://reviews.llvm.org/D90938
2020-11-09 11:35:11 +01:00
Michał Górny fbc0d41bb0 [lldb] [Process/FreeBSDRemote] Fix "Fix attaching via lldb-server"
One of the changes seems to have been lost in rebase.  Reapply.
2020-11-03 17:16:57 +01:00
Michał Górny 952ddc9866 [lldb] [Plugins/FreeBSDRemote] Disable GetMemoryRegionInfo()
Disable GetMemoryRegionInfo() in order to unbreak expression parsing.
For some reason, the presence of non-stub function causes LLDB to fail
to detect system libraries correctly.  Through being unable to find
mmap() and allocate memory, this leads to expression parser being
broken.

The issue is non-trivial and it is going to require more time debugging.
On the other hand, the downsides of missing the function are minimal
(2 failing tests), and the benefit of working expression parser
justifies disabling it temporarily.  Furthermore, the old FreeBSD plugin
did not implement it anyway, so it allows us to switch to the new plugin
without major regressions.

The really curious part is that the respective code in the NetBSD plugin
yields very similar results, yet does not seem to break the expression
parser.

Differential Revision: https://reviews.llvm.org/D90650
2020-11-03 09:45:51 +01:00
Michał Górny 40d26bc4b1 [lldb] [Process/FreeBSDRemote] Remove GetSharedLibraryInfoAddress override
Remove the NetBSD-specific override of GetSharedLibraryInfoAddress(),
restoring the generic implementation from NativeProcessELF.

Differential Revision: https://reviews.llvm.org/D90620
2020-11-03 09:45:50 +01:00
Michał Górny 8e6bcbb417 [lldb] [Process/FreeBSDRemote] Fix attaching via lldb-server
Fix two bugs that caused attaching to a process in a pre-connected
lldb-server to fail.  These are:

1. Prematurely reporting status in NativeProcessFreeBSD::Attach().
   The SetState() call defaulted to notify the process, and LLGS tried
   to send the stopped packet before the process instance was assigned
   to it.  While at it, add an assert for that in LLGS.

2. Duplicate call to ReinitializeThreads() (via SetupTrace()) that
   overwrote the stopped status in threads.  Now SetupTrace() is called
   directly by NativeProcessFreeBSD::Attach() (not the Factory) in place
   of ReinitializeThreads().

This fixes at least commands/process/attach/TestProcessAttach.py
and python_api/hello_world/TestHelloWorld.py.

Differential Revision: https://reviews.llvm.org/D90525
2020-11-03 09:45:50 +01:00
Michał Górny 8e7ea99c38 [lldb] [Process/FreeBSDRemote] Enable watchpoint support
Replace the inline x86 watchpoint handling code with the reusable
NativeRegisterContextWatchpoint_x86.  Implement watchpoint support
in NativeThreadFreeBSD and SIGTRAP handling for watchpoints.

Un-skip all concurrent_events tests as they pass with the new plugin.

Differential Revision: https://reviews.llvm.org/D90102
2020-10-27 15:38:00 +01:00
Michał Górny 87d38831d9 [lldb] [Process/FreeBSDRemote] Initial multithreading support
Implement initial support for watching thread creation and termination.
Update ptrace() calls to correctly indicate requested thread.
Watchpoints are not supported yet.

This patch fixes at least multithreaded register tests.

Differential Revision: https://reviews.llvm.org/D89413
2020-10-15 17:37:37 +02:00
Pavel Labath 2c4226f8ac [lldb-server][linux] Add ability to allocate memory
This patch adds support for the _M and _m gdb-remote packets, which
(de)allocate memory in the inferior. This works by "injecting" a
m(un)map syscall into the inferior. This consists of:
- finding an executable page of memory
- writing the syscall opcode to it
- setting up registers according to the os syscall convention
- single stepping over the syscall

The advantage of this approach over calling the mmap function is that
this works even in case the mmap function is buggy or unavailable. The
disadvantage is it is more platform-dependent, which is why this patch
only works on X86 (_32 and _64) right now. Adding support for other
linux architectures should be easy and consist of defining the
appropriate syscall constants. Adding support for other OSes depends on
the its ability to do a similar trick.

Differential Revision: https://reviews.llvm.org/D89124
2020-10-14 15:02:09 +02:00
Michał Górny 8dc2faf642 [lldb] [Process/FreeBSDRemote] Fix double semicolon 2020-10-10 18:54:52 +02:00
Michał Górny 9a37587ee3 [lldb] [Process/FreeBSDRemote] Kill process via PT_KILL
Use PT_KILL to kill the stopped process.  This ensures that the process
termination is reported properly and fixes delay/error on killing it.

Differential Revision: https://reviews.llvm.org/D89182
2020-10-10 18:54:05 +02:00
Michał Górny 1a600266c3 [lldb] Initial version of FreeBSD remote process plugin
Add a new FreeBSD Process plugin using client/server model.  This plugin
is based on the one used by NetBSD.  It currently supports a subset
of functionality for amd64.  It is automatically used when spawning
lldb-server.  It can also be used by lldb client by setting
FREEBSD_REMOTE_PLUGIN environment variable (to any value).

The code is capable of debugging simple single-threaded programs.  It
supports general purpose, debug and FPU registers (up to XMM) of amd64,
basic signalling, software breakpoints.

Adding the support for the plugin involves removing some dead code
from FreeBSDPlatform plugin (that was not ever used because
CanDebugProcess() returned false), and replacing it with appropriate
code from NetBSD platform support.

Differential Revision: https://reviews.llvm.org/D88796
2020-10-08 16:03:00 +02:00