linux-toradex.git/scripts/recordmcount.c, branch v4.4-rc6

recordmcount: arm64: Replace the ignored mcount call into nop

2015-11-03T15:50:29+00:00

By now, the recordmcount only records the function that in
following sections:
.text/.ref.text/.sched.text/.spinlock.text/.irqentry.text/
.kprobes.text/.text.unlikely

For the function that not in these sections, the call mcount
will be in place and not be replaced when kernel boot up. And
it will bring performance overhead, such as do_mem_abort (in
.exception.text section). This patch make the call mcount to
nop for this case in recordmcount.

Link: http://lkml.kernel.org/r/1446019445-14421-1-git-send-email-huawei.libin@huawei.com
Link: http://lkml.kernel.org/r/1446193864-24593-4-git-send-email-huawei.libin@huawei.com

Cc: 
Cc: 
Cc: 
Cc:  # 3.18+
Acked-by: Will Deacon 
Signed-off-by: Li Bin 
Signed-off-by: Steven Rostedt

recordmcount: x86: Assign a meaningful value to rel_type_nop

2015-11-02T18:34:32+00:00

Although, the default value of rel_type_nop is zero, and the value
of R_386_NONE/R_X86_64_NONE is zero too, but it should be assigned
a meaningful value explicitly, otherwise it looks confused.

Assign R_386_NONE to rel_type_nop for 386, assign R_X86_64_NONE
to rel_type_nop for x86_64.

Link: http://lkml.kernel.org/r/1446020606-16352-1-git-send-email-huawei.libin@huawei.com

Signed-off-by: Li Bin 
Signed-off-by: Steven Rostedt

s390/ftrace,kprobes: allow to patch first instruction

2014-10-27T12:27:27+00:00

If the function tracer is enabled, allow to set kprobes on the first
instruction of a function (which is the function trace caller):

If no kprobe is set handling of enabling and disabling function tracing
of a function simply patches the first instruction. Either it is a nop
(right now it's an unconditional branch, which skips the mcount block),
or it's a branch to the ftrace_caller() function.

If a kprobe is being placed on a function tracer calling instruction
we encode if we actually have a nop or branch in the remaining bytes
after the breakpoint instruction (illegal opcode).
This is possible, since the size of the instruction used for the nop
and branch is six bytes, while the size of the breakpoint is only
two bytes.
Therefore the first two bytes contain the illegal opcode and the last
four bytes contain either "0" for nop or "1" for branch. The kprobes
code will then execute/simulate the correct instruction.

Instruction patching for kprobes and function tracer is always done
with stop_machine(). Therefore we don't have any races where an
instruction is patched concurrently on a different cpu.
Besides that also the program check handler which executes the function
trace caller instruction won't be executed concurrently to any
stop_machine() execution.

This allows to keep full fault based kprobes handling which generates
correct pt_regs contents automatically.

Signed-off-by: Heiko Carstens 
Signed-off-by: Martin Schwidefsky

s390/ftrace: remove 31 bit ftrace support

2014-10-09T07:14:18+00:00

31 bit and 64 bit diverge more and more and it is rather painful
to keep both parts running.
To make things simpler just remove the 31 bit support which nobody
uses anyway.

Signed-off-by: Heiko Carstens 
Signed-off-by: Martin Schwidefsky

Merge branch 'misc' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild

2014-06-13T04:29:20+00:00

Pull kbuild misc updates from Michal Marek:
 "This is the non-critical part of kbuild for v3.16-rc1:
   - make deb-pkg can do s390x and arm64
   - new patterns in scripts/tags.sh
   - scripts/tags.sh skips userspace tools' sources (which sometimes
     have copies of kernel structures) and symlinks
   - improvements to the objdiff tool
   - two new coccinelle patches
   - other minor fixes"

* 'misc' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild:
  scripts: objdiff: support directories for the augument of record command
  scripts: objdiff: fix a comment
  scripts: objdiff: change the extension of disassembly from .o to .dis
  scripts: objdiff: improve path flexibility for record command
  scripts: objdiff: remove unnecessary code
  scripts: objdiff: direct error messages to stderr
  scripts: objdiff: get the path to .tmp_objdiff more simply
  deb-pkg: Add automatic support for s390x architecture
  coccicheck: Add unneeded return variable test
  kbuild: Fix a typo in documentation
  kbuild: trivial - use tabs for code indent where possible
  kbuild: trivial - remove trailing empty lines
  coccinelle: Check for missing NULL terminators in of_device_id tables
  scripts/tags.sh: ignore symlink'ed source files
  scripts/tags.sh: add regular expression replacement pattern for memcg
  builddeb: add arm64 in the supported architectures
  builddeb: use $OBJCOPY variable instead of objcopy
  scripts/tags.sh: ignore code of user space tools
  scripts/tags.sh: add pattern for DEFINE_HASHTABLE
  .gitignore: ignore Module.symvers in all directories

kbuild: trivial - remove trailing empty lines

2014-06-09T22:04:06+00:00

Signed-off-by: Masahiro Yamada

ftrace: Add arm64 support to recordmcount

2014-05-29T08:04:31+00:00

Recordmcount utility under scripts is run, after compiling each object,
to find out all the locations of calling _mcount() and put them into
specific seciton named __mcount_loc.
Then linker collects all such information into a table in the kernel image
(between __start_mcount_loc and __stop_mcount_loc) for later use by ftrace.

This patch adds arm64 specific definitions to identify such locations.
There are two types of implementation, C and Perl. On arm64, only C version
is used to build the kernel now that CONFIG_HAVE_C_RECORDMCOUNT is on.
But Perl version is also maintained.

This patch also contains a workaround just in case where a header file,
elf.h, on host machine doesn't have definitions of EM_AARCH64 nor
R_AARCH64_ABS64. Without them, compiling C version of recordmcount will
fail.

Acked-by: Will Deacon 
Signed-off-by: AKASHI Takahiro 
Signed-off-by: Will Deacon

metag: ftrace support

2013-03-02T20:09:55+00:00

Add ftrace support for metag.

Signed-off-by: James Hogan 
Cc: Frederic Weisbecker 
Cc: Ingo Molnar 
Reviewed-by: Steven Rostedt

ftrace/s390: mcount offset calculation

2011-05-16T19:05:06+00:00

Do the mcount offset adjustment in the recordmcount.pl/recordmcount.[ch]
at compile time and not in ftrace_call_adjust at run time.

Signed-off-by: Martin Schwidefsky 
Signed-off-by: Steven Rostedt

ftrace/x86: mcount offset calculation

2011-05-16T18:55:57+00:00

Do the mcount offset adjustment in the recordmcount.pl/recordmcount.[ch]
at compile time and not in ftrace_call_adjust at run time.

Signed-off-by: Martin Schwidefsky 
Signed-off-by: Steven Rostedt