linux/tools
Josh Poimboeuf 6d01f28bc0 objtool: Support new GCC 6 switch jump table pattern
This fixes some false positive objtool warnings seen with gcc 6.1.1:

  kernel/trace/ring_buffer.o: warning: objtool: ring_buffer_read_page()+0x36c: sibling call from callable instruction with changed frame pointer
  arch/x86/kernel/reboot.o: warning: objtool: native_machine_emergency_restart()+0x139: sibling call from callable instruction with changed frame pointer
  lib/xz/xz_dec_stream.o: warning: objtool: xz_dec_run()+0xc2: sibling call from callable instruction with changed frame pointer

With GCC 6, a new code pattern is sometimes used to access a switch
statement jump table in .rodata, which objtool doesn't yet recognize:

  mov [rodata addr],%reg1
  ... some instructions ...
  jmpq *(%reg1,%reg2,8)

Add support for detecting that pattern.  The detection code is rather
crude, but it's still effective at weeding out false positives and
catching real warnings.  It can be refined later once objtool starts
reading DWARF CFI.

Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/b8c9503b4ad8c8a827cc5400db4c1b40a3ea07bc.1469751119.git.jpoimboe@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-07-29 16:56:21 +02:00
..
arch tools: Copy the bitsperlong.h files from the kernel 2016-07-12 15:20:39 -03:00
build perf build: Add sdt feature detection 2016-07-13 23:09:09 -03:00
cgroup
firewire
gpio tools/gpio: Add missing initialization of device_name 2016-03-31 11:51:30 +02:00
hv tools: hv: lsvmbus: add pci pass-through UUID 2016-05-01 09:23:14 -07:00
iio iio: generic_buffer: Fix --trigger-num option 2016-06-11 17:38:06 +01:00
include tools: Copy linux/{hash,poison}.h and check for drift 2016-07-18 18:41:50 -03:00
kvm/kvm_stat tools: kvm_stat: Add comments 2016-05-25 16:12:06 +02:00
laptop/freefall
lguest tools/lguest: Force disable tboot and APM 2016-04-22 10:29:03 +02:00
lib tools lib fd array: Allow associating a pointer cookie with each entry 2016-07-15 17:27:46 -03:00
net tools: bpf_jit_disasm: check for klogctl failure 2016-05-08 23:32:59 -04:00
nfsd
objtool objtool: Support new GCC 6 switch jump table pattern 2016-07-29 16:56:21 +02:00
perf Revert "perf tools: event.h needs asm/perf_regs.h" 2016-07-25 11:58:56 -03:00
power Merge branch 'for-4.7/acpi6.1' into libnvdimm-for-next 2016-05-18 10:07:19 -07:00
scripts tools build: Fix objtool build with ARCH=x86_64 2016-07-22 16:37:44 -03:00
spi
testing Merge branch 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2016-07-25 15:34:18 -07:00
thermal/tmon
time
usb usbip: adding names db to port operation 2016-05-03 14:32:07 -07:00
virtio tools/virtio: add noring tool 2016-06-06 13:00:11 +03:00
vm tools/vm/slabinfo: fix an unintentional printf 2016-07-23 10:25:54 +09:00
Makefile - move kvm_stat tool from QEMU repo into tools/kvm/kvm_stat 2016-05-27 13:41:54 -07:00