This adds a "self" argument to to_supports_btrace. Due to how one
implementation of this method is shared with gdbserver this required a
small change to gdbserver as well.
2014-02-19 Tom Tromey <tromey@redhat.com>
* common/linux-btrace.c (linux_supports_btrace): Add "ops"
argument.
* common/linux-btrace.h (linux_supports_btrace): Update.
* remote.c (remote_supports_btrace): Add "self" argument.
* target-delegates.c: Rebuild.
* target.c (target_supports_btrace): Remove.
* target.h (struct target_ops) <to_supports_btrace>: Add
target_ops argument.
(target_supports_btrace): New define.
2014-02-19 Tom Tromey <tromey@redhat.com>
* target.h (struct target_ops) <supports_btrace>: Add target_ops
argument.
(target_supports_btrace): Update.
Read branch trace data incrementally and extend the current trace rather than
discarding it and reading the entire trace buffer each time.
If the branch trace buffer overflowed, we can't extend the current trace so we
discard it and start anew by reading the entire branch trace buffer.
2014-01-16 Markus Metzger <markus.t.metzger@intel.com>
* common/linux-btrace.c (perf_event_read_bts, linux_read_btrace):
Support delta reads.
(linux_disable_btrace): Change return type.
* common/linux-btrace.h (linux_read_btrace): Change parameters
and return type to allow error reporting. Update users.
(linux_disable_btrace): Change return type. Update users.
* common/btrace-common.h (btrace_read_type) <BTRACE_READ_DELTA>:
New.
(btrace_error): New.
(btrace_block) <begin>: Comment on BEGIN == 0.
* btrace.c (btrace_compute_ftrace): Start from the end of
the current trace.
(btrace_stitch_trace, btrace_clear_history): New.
(btrace_fetch): Read delta trace, return if replaying.
(btrace_clear): Move clear history code to btrace_clear_history.
(parse_xml_btrace): Throw an error if parsing failed.
* target.h (struct target_ops) <to_read_btrace>: Change parameters
and return type to allow error reporting.
(target_read_btrace): Change parameters and return type to allow
error reporting.
* target.c (target_read_btrace): Update.
* remote.c (remote_read_btrace): Support delta reads. Pass
errors on.
* NEWS: Announce it.
gdbserver/
* target.h (target_ops) <read_btrace>: Change parameters and
return type to allow error reporting.
* server.c (handle_qxfer_btrace): Support delta reads. Pass
trace reading errors on.
* linux-low.c (linux_low_read_btrace): Pass trace reading
errors on.
(linux_low_disable_btrace): New.
Try to allocate as much buffer as we can for each thread with a maximum
of 64KB.
2014-01-16 Markus Metzger <markus.t.metzger@intel.com>
* common/linux-btrace.c (linux_enable_btrace): Enlarge buffer.
When it takes more than one iteration to read the BTS trace, the trace from the
previous iteration is leaked. Fix it.
2014-01-16 Markus Metzger <markus.t.metzger@intel.com>
* common/linux-btrace.c (linux_read_btrace): Free trace from
previous iteration.
It is possible to have a build of glibc where SYS_perf_event_open is not
defined (because when the glibc was compiled, the syscall did not exist),
but have newer kernel headers installed so that linux/perf_event.h is
available. In this setup, you get a build failure:
./common/linux-btrace.c: In function 'kernel_supports_btrace':
./common/linux-btrace.c:316:23: error: 'SYS_perf_event_open' undeclared (first use in this function)
Update the ifdef check to also see if the syscall is available.
URL: https://bugs.gentoo.org/473522
Reported-by: William Throwe <wtt6@cornell.edu>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
We've currently got 3 files doing open coded implementations of cpuid.
Each has its own set of workarounds and varying levels of how well
they're written and are generally hardcoded to specific cpuid functions.
If you try to build the latest gdb as a PIE on an i386 system, the build
will fail because one of them lacks PIC workarounds (wrt ebx).
Specifically, we have:
common/linux-btrace.c:
two copies of cpuid asm w/specific args, one has no workarounds
while the other implicitly does to avoid memcpy
go32-nat.c:
two copies of cpuid asm w/specific args, one has workarounds to
avoid memcpy
gdb/testsuite/gdb.arch/i386-cpuid.h:
one general cpuid asm w/many workarounds copied from older gcc
Fortunately, that last header there is pretty damn good -- it handles
lots of edge cases, the code is nice & tight (uses gcc asm operands
rather than manual movs), and is already almost a general library type
header. It's also the basis of what is now the public cpuid.h that is
shipped with gcc-4.3+.
So what I've done is pull that test header out and into gdb/common/
(not sure if there's a better place), synced to the version found in
gcc-4.8.0, put a wrapper API around it, and then cut over all the
existing call points to this new header.
Since the func already has support for "is cpuid supported on this proc",
it makes it trivial to push the i386/x86_64 ifdefs down into this wrapper
API too. Now it can be safely used for all targets and gcc will elide
the unused code for us.
I've verified the gdb.arch testsuite still passes, and this code compiles
for an armv7a host as well as x86_64. The go32-nat code has been left
ifdef-ed out until someone can test & verify the new stuff works (and if
it doesn't, figure out how to make the new code work).
URL: https://bugs.gentoo.org/467806
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
EIST transition, T-states, C1E, or Adaptive Thermal Throttling (AAJ122).
This results in sporadic test fails. Disable btrace on those processors.
gdb/
* common/linux-btrace.c: Include sys/ptrace, sys/types, sys/wait.h,
and signal.h.
(linux_supports_btrace): Add kernel and
cpuid check.
(kernel_supports_btrace): New function.
(cpu_supports_btrace): New function.
(intel_supports_btrace): New function.
Tom Tromey