On an arm64 machine running a CONFIG_RANDOMIZE_BASE=y kernel, perf
kernel symbol resolution fails. Debugging saw symsrc_init calling the
default elf__needs_adjust_symbols() where checks for an ET_DYN (3)
ehdr.e_type failed when they should have succeeded.
Fix by adopting powerpc version of the weak elf__needs_adjust_symbols()
function, as done in commit d233209833 ("perf probe ppc: Fix symbol
fixup issues due to ELF type").
Prior to this patch, perf test 1 would fail:
$ sudo oldperf test -v 1 |& head
1: vmlinux symtab matches kallsyms :
test child forked, pid 33374
Looking at the vmlinux_path (8 entries long)
Using /usr/lib/debug/boot/vmlinux for symbols
ERR : 0xfffe0000100f1000: do_undefinstr not on kallsyms
ERR : 0xfffe0000100f1320: do_sysinstr not on kallsyms
ERR : 0xfffe0000100f13b0: do_debug_exception not on kallsyms
ERR : 0xfffe0000100f1498: do_mem_abort not on kallsyms
ERR : 0xfffe0000100f1580: do_sp_pc_abort not on kallsyms
...
After applying this patch, perf test 1 now succeeds:
$ sudo ./newperf test -v 1 |& head
1: vmlinux symtab matches kallsyms :
test child forked, pid 33378
Looking at the vmlinux_path (8 entries long)
Using /usr/lib/debug/boot/vmlinux for symbols
WARN: 0xffff000008081000: diff name v: do_undefinstr k: __exception_text_start
WARN: 0xffff0000080819e8: diff name v: __irqentry_text_end k: __softirqentry_text_start
WARN: 0xffff000008081d08: diff name v: __entry_text_start k: __softirqentry_text_end
WARN: 0xffff00000809db5c: diff name v: flush_icache_range k: __flush_cache_user_range
WARN: 0xffff000008101908: diff name v: sys_ni_syscall k: sys_vm86old
...
Signed-off-by: Kim Phillips <kim.phillips@arm.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ganapatrao Kulkarni <ganapatrao.kulkarni@cavium.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: linux-arm-kernel@lists.infradead.org
Link: http://lkml.kernel.org/r/20171214175242.e30450f17f93ad675d968fa3@arm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
f1031c8d33