linux/tools
Wang Nan 3dc6c1d54f perf record: Fix crash when kptr is restricted
Before this patch, a simple 'perf record' could fail if kptr_restrict is
set to 1 (for normal user) or 2 (for root):

  # perf record ls
  WARNING: Kernel address maps (/proc/{kallsyms,modules}) are restricted,
  check /proc/sys/kernel/kptr_restrict.

  Samples in kernel functions may not be resolved if a suitable vmlinux
  file is not found in the buildid cache or in the vmlinux path.

  Samples in kernel modules won't be resolved at all.

  If some relocation was applied (e.g. kexec) symbols may be misresolved
  even with a suitable vmlinux or kallsyms file.

  Segmentation fault (core dumped)

This patch skips perf_event__synthesize_kernel_mmap() when kptr is not
available.

Signed-off-by: Wang Nan <wangnan0@huawei.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Fixes: 45e9005690 ("perf machine: Do not bail out if not managing to read ref reloc symbol")
Cc: Zefan Li <lizefan@huawei.com>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1464081688-167940-2-git-send-email-wangnan0@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2016-05-27 09:41:39 -03:00
..
arch
build perf probe: Check if dwarf_getlocations() is available 2016-05-12 11:26:59 -03:00
cgroup
firewire
gpio gpio: present the consumer of a line to userspace 2016-02-25 21:07:23 +01:00
hv tools/hv: Use include/uapi with __EXPORTED_HEADERS__ 2016-02-07 21:34:12 -08:00
iio
include Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2016-03-24 10:02:14 -07:00
laptop/freefall
lguest tools/lguest: Force disable tboot and APM 2016-04-22 10:29:03 +02:00
lib Merge branch 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2016-05-16 14:08:43 -07:00
net tools: bpf_jit_disasm: check for klogctl failure 2016-05-08 23:32:59 -04:00
nfsd
objtool objtool: Detect falling through to the next function 2016-04-16 11:14:17 +02:00
perf perf record: Fix crash when kptr is restricted 2016-05-27 09:41:39 -03:00
power Merge branches 'pm-core', 'powercap' and 'pm-tools' 2016-04-08 21:46:56 +02:00
scripts tools: Move utilities.mak from perf to tools/scripts/ 2016-03-18 13:57:20 -03:00
spi spi: spidev_test: Fix typo in error message 2015-12-08 17:58:56 +00:00
testing Merge branch 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2016-05-16 15:15:17 -07:00
thermal/tmon
time
usb
virtio virtio_ring: Support DMA APIs 2016-03-02 17:01:57 +02:00
vm tools/vm/page-types.c: avoid memset() in walk_pfn() when count == 1 2016-03-17 15:09:34 -07:00
Makefile tools build: Fix perf_clean target 2016-04-25 17:59:36 -03:00