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author | Martin Schwidefsky <schwidefsky@de.ibm.com> | 2019-01-28 08:33:08 +0100 |
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committer | Martin Schwidefsky <schwidefsky@de.ibm.com> | 2019-05-02 13:54:11 +0200 |
commit | 78c98f9074135d3dab4e39544e0a537f92388fce (patch) | |
tree | 6f6d96e8e0911fe2aa27ec89cca52d56d3ed6f7e /arch/s390/kernel/perf_event.c | |
parent | s390/opcodes: add missing instructions to the disassembler (diff) | |
download | linux-78c98f9074135d3dab4e39544e0a537f92388fce.tar.xz linux-78c98f9074135d3dab4e39544e0a537f92388fce.zip |
s390/unwind: introduce stack unwind API
Rework the dump_trace() stack unwinder interface to support different
unwinding algorithms. The new interface looks like this:
struct unwind_state state;
unwind_for_each_frame(&state, task, regs, start_stack)
do_something(state.sp, state.ip, state.reliable);
The unwind_bc.c file contains the implementation for the classic
back-chain unwinder.
One positive side effect of the new code is it now handles ftraced
functions gracefully. It prints the real name of the return function
instead of 'return_to_handler'.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Diffstat (limited to 'arch/s390/kernel/perf_event.c')
-rw-r--r-- | arch/s390/kernel/perf_event.c | 16 |
1 files changed, 5 insertions, 11 deletions
diff --git a/arch/s390/kernel/perf_event.c b/arch/s390/kernel/perf_event.c index 0d770e513abf..fcb6c2e92b07 100644 --- a/arch/s390/kernel/perf_event.c +++ b/arch/s390/kernel/perf_event.c @@ -21,6 +21,7 @@ #include <asm/lowcore.h> #include <asm/processor.h> #include <asm/sysinfo.h> +#include <asm/unwind.h> const char *perf_pmu_name(void) { @@ -219,20 +220,13 @@ static int __init service_level_perf_register(void) } arch_initcall(service_level_perf_register); -static int __perf_callchain_kernel(void *data, unsigned long address, int reliable) -{ - struct perf_callchain_entry_ctx *entry = data; - - perf_callchain_store(entry, address); - return 0; -} - void perf_callchain_kernel(struct perf_callchain_entry_ctx *entry, struct pt_regs *regs) { - if (user_mode(regs)) - return; - dump_trace(__perf_callchain_kernel, entry, NULL, regs->gprs[15]); + struct unwind_state state; + + unwind_for_each_frame(&state, current, regs, 0) + perf_callchain_store(entry, state.ip); } /* Perf definitions for PMU event attributes in sysfs */ |