ARM: oprofile: Fix backtraces in timer mode

Always allow backtraces when using oprofile on ARM, even if a PMU
isn't present. Restores functionality originally introduced in commit
1b7b56982f ("oprofile: Always allow
backtraces on ARM") by Richard Purdie.

It is not that obvious, but there is now only one oprofile_arch_init()
function. So the .backtrace callback is available also in timer mode.

Implemented by removing code and using stubs for oprofile_perf_{init,
exit} provided by <linux/oprofile.h>. This allows cleaning of other
architecture specific implementations too.

Cc: stable@kernel.org # 37.x
Signed-off-by: Ari Kauppi <kauppi@papupata.org>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Robert Richter <robert.richter@amd.com>
This commit is contained in:
Ari Kauppi 2011-01-20 13:57:19 -05:00 committed by Robert Richter
parent 1ea1bdf7fa
commit d14dd7e20d
2 changed files with 11 additions and 10 deletions

View File

@ -10,8 +10,6 @@
*/
#include <linux/cpumask.h>
#include <linux/err.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/mutex.h>
#include <linux/oprofile.h>
@ -46,6 +44,7 @@ char *op_name_from_perf_id(void)
return NULL;
}
}
#endif
static int report_trace(struct stackframe *frame, void *d)
{
@ -111,6 +110,7 @@ static void arm_backtrace(struct pt_regs * const regs, unsigned int depth)
int __init oprofile_arch_init(struct oprofile_operations *ops)
{
/* provide backtrace support also in timer mode: */
ops->backtrace = arm_backtrace;
return oprofile_perf_init(ops);
@ -120,11 +120,3 @@ void __exit oprofile_arch_exit(void)
{
oprofile_perf_exit();
}
#else
int __init oprofile_arch_init(struct oprofile_operations *ops)
{
pr_info("oprofile: hardware counters not available\n");
return -ENODEV;
}
void __exit oprofile_arch_exit(void) {}
#endif /* CONFIG_HW_PERF_EVENTS */

View File

@ -16,6 +16,8 @@
#include <linux/types.h>
#include <linux/spinlock.h>
#include <linux/init.h>
#include <linux/errno.h>
#include <linux/printk.h>
#include <asm/atomic.h>
/* Each escaped entry is prefixed by ESCAPE_CODE
@ -190,6 +192,13 @@ int oprofile_write_commit(struct op_entry *entry);
int __init oprofile_perf_init(struct oprofile_operations *ops);
void oprofile_perf_exit(void);
char *op_name_from_perf_id(void);
#else
static inline int __init oprofile_perf_init(struct oprofile_operations *ops)
{
pr_info("oprofile: hardware counters not available\n");
return -ENODEV;
}
static inline void oprofile_perf_exit(void) { }
#endif /* CONFIG_HW_PERF_EVENTS */
#endif /* OPROFILE_H */