diff options
Diffstat (limited to 'arch/s390/kernel/perf_event.c')
| -rw-r--r-- | arch/s390/kernel/perf_event.c | 41 |
1 files changed, 41 insertions, 0 deletions
diff --git a/arch/s390/kernel/perf_event.c b/arch/s390/kernel/perf_event.c index c27321cb09..dfa77da2fd 100644 --- a/arch/s390/kernel/perf_event.c +++ b/arch/s390/kernel/perf_event.c @@ -15,7 +15,10 @@ #include <linux/export.h> #include <linux/seq_file.h> #include <linux/spinlock.h> +#include <linux/uaccess.h> +#include <linux/compat.h> #include <linux/sysfs.h> +#include <asm/stacktrace.h> #include <asm/irq.h> #include <asm/cpu_mf.h> #include <asm/lowcore.h> @@ -212,6 +215,44 @@ void perf_callchain_kernel(struct perf_callchain_entry_ctx *entry, } } +void perf_callchain_user(struct perf_callchain_entry_ctx *entry, + struct pt_regs *regs) +{ + struct stack_frame_user __user *sf; + unsigned long ip, sp; + bool first = true; + + if (is_compat_task()) + return; + perf_callchain_store(entry, instruction_pointer(regs)); + sf = (void __user *)user_stack_pointer(regs); + pagefault_disable(); + while (entry->nr < entry->max_stack) { + if (__get_user(sp, &sf->back_chain)) + break; + if (__get_user(ip, &sf->gprs[8])) + break; + if (ip & 0x1) { + /* + * If the instruction address is invalid, and this + * is the first stack frame, assume r14 has not + * been written to the stack yet. Otherwise exit. + */ + if (first && !(regs->gprs[14] & 0x1)) + ip = regs->gprs[14]; + else + break; + } + perf_callchain_store(entry, ip); + /* Sanity check: ABI requires SP to be aligned 8 bytes. */ + if (!sp || sp & 0x7) + break; + sf = (void __user *)sp; + first = false; + } + pagefault_enable(); +} + /* Perf definitions for PMU event attributes in sysfs */ ssize_t cpumf_events_sysfs_show(struct device *dev, struct device_attribute *attr, char *page) |