A-Team_Digital_Solutions/android_kernel_motorola_sm6375
Watch
2
0
Fork
You've already forked android_kernel_motorola_sm6375
 0
mirror of https://github.com/BobTheBlinker/android_kernel_motorola_sm6375.git synced 2026-10-29 03:01:39 -04:00
Code Issues Projects Releases Packages Wiki Activity

perf: Add ability to attach user level registers dump to sample

Browse source 
Introducing PERF_SAMPLE_REGS_USER sample type bit to trigger the dump of
user level registers on sample. Registers we want to dump are specified
by sample_regs_user bitmask.

Only user level registers are dumped at the moment. Meaning the register
values of the user space context as it was before the user entered the
kernel for whatever reason (syscall, irq, exception, or a PMI happening
in userspace).

The layout of the sample_regs_user bitmap is described in
asm/perf_regs.h for archs that support register dump.

This is going to be useful to bring Dwarf CFI based stack unwinding on
top of samples.

Original-patch-by: Frederic Weisbecker <[email protected]>
[ Dump registers ABI specification. ]
Signed-off-by: Jiri Olsa <[email protected]>
Suggested-by: Stephane Eranian <[email protected]>
Cc: "Frank Ch. Eigler" <[email protected]>
Cc: Arun Sharma <[email protected]>
Cc: Benjamin Redelings <[email protected]>
Cc: Corey Ashford <[email protected]>
Cc: Cyrill Gorcunov <[email protected]>
Cc: Frank Ch. Eigler <[email protected]>
Cc: Frederic Weisbecker <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Masami Hiramatsu <[email protected]>
Cc: Paul Mackerras <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Robert Richter <[email protected]>
Cc: Stephane Eranian <[email protected]>
Cc: Tom Zanussi <[email protected]>
Cc: Ulrich Drepper <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
This commit is contained in:
Jiri Olsa 2012-08-07 15:20:37 +02:00 • committed by Arnaldo Carvalho de Melo
commit 4018994f3d
4 changed files with 119 additions and 3 deletions
Download patch file Download diff file Expand all files Collapse all files

66
kernel/events/core.c
View file

@ -3756,6 +3756,37 @@ int perf_unregister_guest_info_callbacks(struct perf_guest_info_callbacks *cbs)
}
EXPORT_SYMBOL_GPL(perf_unregister_guest_info_callbacks);
static void
perf_output_sample_regs(struct perf_output_handle *handle,
struct pt_regs *regs, u64 mask)
{
int bit;
for_each_set_bit(bit, (const unsigned long *) &mask,
sizeof(mask) * BITS_PER_BYTE) {
u64 val;
val = perf_reg_value(regs, bit);
perf_output_put(handle, val);
}
}
static void perf_sample_regs_user(struct perf_regs_user *regs_user,
struct pt_regs *regs)
{
if (!user_mode(regs)) {
if (current->mm)
regs = task_pt_regs(current);
else
regs = NULL;
}
if (regs) {
regs_user->regs = regs;
regs_user->abi = perf_reg_abi(current);
}
}
static void __perf_event_header__init_id(struct perf_event_header *header,
struct perf_sample_data *data,
struct perf_event *event)
@ -4016,6 +4047,23 @@ void perf_output_sample(struct perf_output_handle *handle,
perf_output_put(handle, nr);
}
}
if (sample_type & PERF_SAMPLE_REGS_USER) {
u64 abi = data->regs_user.abi;
/*
* If there are no regs to dump, notice it through
* first u64 being zero (PERF_SAMPLE_REGS_ABI_NONE).
*/
perf_output_put(handle, abi);
if (abi) {
u64 mask = event->attr.sample_regs_user;
perf_output_sample_regs(handle,
data->regs_user.regs,
mask);
}
}
}
void perf_prepare_sample(struct perf_event_header *header,
@ -4067,6 +4115,20 @@ void perf_prepare_sample(struct perf_event_header *header,
}
header->size += size;
}
if (sample_type & PERF_SAMPLE_REGS_USER) {
/* regs dump ABI info */
int size = sizeof(u64);
perf_sample_regs_user(&data->regs_user, regs);
if (data->regs_user.regs) {
u64 mask = event->attr.sample_regs_user;
size += hweight64(mask) * sizeof(u64);
}
header->size += size;
}
}
static void perf_event_output(struct perf_event *event,
@ -6142,6 +6204,10 @@ static int perf_copy_attr(struct perf_event_attr __user *uattr,
attr->branch_sample_type = mask;
}
}
if (attr->sample_type & PERF_SAMPLE_REGS_USER)
ret = perf_reg_validate(attr->sample_regs_user);
out:
return ret;