linux-toradex.git/scripts/recordmcount.c, branch v4.11-rc3

recordmcount: arm: Implement make_nop

2016-11-14T21:43:00+00:00

In similar spirit to x86 and arm64 support, add a make_nop_arm()
to replace calls to mcount with a nop in sections that aren't
traced.

Link: http://lkml.kernel.org/r/20161018234200.5804-1-sboyd@codeaurora.org

Acked-by: Russell King 
Acked-by: Rabin Vincent 
Signed-off-by: Stephen Boyd 
Signed-off-by: Steven Rostedt

nmi_backtrace: generate one-line reports for idle cpus

2016-10-08T01:46:30+00:00

When doing an nmi backtrace of many cores, most of which are idle, the
output is a little overwhelming and very uninformative.  Suppress
messages for cpus that are idling when they are interrupted and just
emit one line, "NMI backtrace for N skipped: idling at pc 0xNNN".

We do this by grouping all the cpuidle code together into a new
.cpuidle.text section, and then checking the address of the interrupted
PC to see if it lies within that section.

This commit suitably tags x86 and tile idle routines, and only adds in
the minimal framework for other architectures.

Link: http://lkml.kernel.org/r/1472487169-14923-5-git-send-email-cmetcalf@mellanox.com
Signed-off-by: Chris Metcalf 
Acked-by: Peter Zijlstra (Intel) 
Tested-by: Peter Zijlstra (Intel) 
Tested-by: Daniel Thompson  [arm]
Tested-by: Petr Mladek 
Cc: Aaron Tomlin 
Cc: Peter Zijlstra (Intel) 
Cc: "Rafael J. Wysocki" 
Cc: Russell King 
Cc: Thomas Gleixner 
Cc: Ingo Molnar 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

scripts/recordmcount.c: account for .softirqentry.text

2016-09-28T23:19:02+00:00

be7635e7287e ("arch, ftrace: for KASAN put hard/soft IRQ entries into
separate sections") added .softirqentry.text section, but it was not added
to recordmcount.  So functions in the section are untracable.  Add the
section to scripts/recordmcount.c and scripts/recordmcount.pl.

Fixes: be7635e7287e ("arch, ftrace: for KASAN put hard/soft IRQ entries into separate sections")
Link: http://lkml.kernel.org/r/1474902626-73468-1-git-send-email-dvyukov@google.com
Signed-off-by: Dmitry Vyukov 
Acked-by: Steve Rostedt 
Cc: 	[4.6+]
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

ftrace/recordmcount: Work around for addition of metag magic but not relocations

2016-08-02T16:57:24+00:00

glibc recently did a sync up (94e73c95d9b5 "elf.h: Sync with the gabi
webpage") that added a #define for EM_METAG but did not add relocations

This triggers build errors:

scripts/recordmcount.c: In function 'do_file':
scripts/recordmcount.c:466:28: error: 'R_METAG_ADDR32' undeclared (first use in this function)
  case EM_METAG:  reltype = R_METAG_ADDR32;
                            ^~~~~~~~~~~~~~
scripts/recordmcount.c:466:28: note: each undeclared identifier is reported only once for each function it appears in
scripts/recordmcount.c:468:20: error: 'R_METAG_NONE' undeclared (first use in this function)
     rel_type_nop = R_METAG_NONE;
                    ^~~~~~~~~~~~

Work around this change with some more #ifdefery for the relocations.

Fedora Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=1354034

Link: http://lkml.kernel.org/r/1468005530-14757-1-git-send-email-labbott@redhat.com

Cc: stable@vger.kernel.org # v3.9+
Cc: James Hogan 
Fixes: 00512bdd4573 ("metag: ftrace support")
Reported-by: Ross Burton 
Signed-off-by: Laura Abbott 
Signed-off-by: Steven Rostedt

ftrace/scripts: Fix incorrect use of sprintf in recordmcount

2016-01-04T16:13:16+00:00

Fix build warning:

scripts/recordmcount.c:589:4: warning: format not a string
literal and no format arguments [-Wformat-security]
    sprintf("%s: failed\n", file);

Fixes: a50bd43935586 ("ftrace/scripts: Have recordmcount copy the object file")
Link: http://lkml.kernel.org/r/1451516801-16951-1-git-send-email-colin.king@canonical.com

Cc: Li Bin 
Cc: Russell King 
Cc: Will Deacon 
Cc: stable@vger.kernel.org # 2.6.37+
Signed-off-by: Colin Ian King 
Signed-off-by: Steven Rostedt

ftrace/scripts: Have recordmcount copy the object file

2015-12-16T20:46:07+00:00

Russell King found that he had weird side effects when compiling the kernel
with hard linked ccache. The reason was that recordmcount modified the
kernel in place via mmap, and when a file gets modified twice by
recordmcount, it will complain about it. To fix this issue, Russell wrote a
patch that checked if the file was hard linked more than once and would
unlink it if it was.

Linus Torvalds was not happy with the fact that recordmcount does this in
place modification. Instead of doing the unlink only if the file has two or
more hard links, it does the unlink all the time. In otherwords, it always
does a copy if it changed something. That is, it does the write out if a
change was made.

Cc: stable@vger.kernel.org # 2.6.37+
Signed-off-by: Steven Rostedt

scripts: recordmcount: break hardlinks

2015-12-16T14:28:23+00:00

recordmcount edits the file in-place, which can cause problems when
using ccache in hardlink mode.  Arrange for recordmcount to break a
hardlinked object.

Link: http://lkml.kernel.org/r/E1a7MVT-0000et-62@rmk-PC.arm.linux.org.uk

Cc: stable@vger.kernel.org # 2.6.37+
Signed-off-by: Russell King 
Signed-off-by: Steven Rostedt

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