9 Commits

Author SHA1 Message Date
Elliot Goodrich
5551657b31 [lldb] Add missing StringExtras.h includes
In preparation for removing the `#include "llvm/ADT/StringExtras.h"`
from the header to source file of `llvm/Support/Error.h`, first add in
all the missing includes that were previously included transitively
through this header.

This is fixing all files missed in b0abd4893fa1, 39d8e6e22cd1, and
a11efd49266f.

Differential Revision: https://reviews.llvm.org/D154775
2023-07-09 14:09:21 +01:00
Jordan Rupprecht
6db44e52ce [Linux] Add kernel.yama.ptrace_scope note when ptrace fails to attach.
A common reason for LLDB failing to attach to an already-running process on Linux is the Yama security module: https://www.kernel.org/doc/Documentation/security/Yama.txt. This patch adds an explaination and suggested fix when it detects that case happening.

This was previously proposed in D106226, but hasn't been updated in a while. The last request was to put the check in a target-specific location, which is the approach this patch takes. I believe Yama only exists on Linux, so it's put in that package.

This has no end-to-end test because I'm not sure how to set `ptrace_scope` in a test environment -- if there are suggestions on how to do that, I'd be happy to add it. (Also, setting it to `3` is comically irreversible). I tested this locally.

Reviewed By: DavidSpickett, labath

Differential Revision: https://reviews.llvm.org/D144904
2023-03-02 13:51:30 -08:00
Kazu Hirata
2fe8327406 [lldb] Use std::optional instead of llvm::Optional (NFC)
This patch replaces (llvm::|)Optional< with std::optional<.  I'll post
a separate patch to clean up the "using" declarations, #include
"llvm/ADT/Optional.h", etc.

This is part of an effort to migrate from llvm::Optional to
std::optional:

https://discourse.llvm.org/t/deprecating-llvm-optional-x-hasvalue-getvalue-getvalueor/63716
2023-01-07 14:18:35 -08:00
Kazu Hirata
f190ce625a [lldb] Add #include <optional> (NFC)
This patch adds #include <optional> to those files containing
llvm::Optional<...> or Optional<...>.

I'll post a separate patch to actually replace llvm::Optional with
std::optional.

This is part of an effort to migrate from llvm::Optional to
std::optional:

https://discourse.llvm.org/t/deprecating-llvm-optional-x-hasvalue-getvalue-getvalueor/63716
2023-01-07 13:43:00 -08:00
Walter Erquinigo
ddd576ab87 [lldb] Prevent race condition when fetching /proc/cpuinfo
@clayborg found a potential race condition when setting a static
variable. The fix seems simply to use call_once.

All relevant tests pass.

Differential Revision: https://reviews.llvm.org/D131081
2022-08-08 12:31:42 -07:00
Walter Erquinigo
6a5355e8a1 [trace][intelpt] Support system-wide tracing [20] - Rename some fields in the schema
As discusses offline with @jj10305, we are updating some naming used throughout the code, specially in the json schema

- traceBuffer -> iptTrace
- core -> cpu

Differential Revision: https://reviews.llvm.org/D127817
2022-06-16 11:42:22 -07:00
Walter Erquinigo
1f49714d3e [trace][intelpt] Support system-wide tracing [4] - Support per core tracing on lldb-server
This diffs implements per-core tracing on lldb-server. It also includes tests that ensure that tracing can be initiated from the client and that the jLLDBGetState ppacket returns the list of trace buffers per core.

This doesn't include any decoder changes.

Finally, this makes some little changes here and there improving the existing code.

A specific piece of code that can't reliably be tested is when tracing
per core fails due to permissions. In this case we add a
troubleshooting message and this is the manual test:

```
/proc/sys/kernel/perf_event_paranoid set to 1

(lldb) process trace start --per-core-tracing                                         error: perf event syscall failed: Permission denied
 You might need that /proc/sys/kernel/perf_event_paranoid has a value of 0 or -1.
``

Differential Revision: https://reviews.llvm.org/D124858
2022-05-17 12:46:54 -07:00
Weverything
3dd00461f9 [trace][intelpt] Fix out-of-bounds access.
The StringRef single argument constructor expects a null-terminated
string.  Explicitly pass the size to prevent reading pass the end
of the array.
2022-05-03 16:07:58 -07:00
Walter Erquinigo
5de0a3e9da [trace][intelpt] Support system-wide tracing [1] - Add a method for accessing the list of logical core ids
In order to open perf events per core, we need to first get the list of
core ids available in the system. So I'm adding a function that does
that by parsing /proc/cpuinfo. That seems to be the simplest and most
portable way to do that.

Besides that, I made a few refactors and renames to reflect better that
the cpu info that we use in lldb-server comes from procfs.

Differential Revision: https://reviews.llvm.org/D124573
2022-05-02 08:48:49 -07:00