| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Date: Thu, 11 Dec 2008 17:42:02 +0100
From: Robert Richter <robert.richter@....com>
To: LKML <linux-kernel@...r.kernel.org>
CC: oprofile-list <oprofile-list@...ts.sourceforge.net>,
Ingo Molnar <mingo@...e.hu>,
Steven Rostedt <rostedt@...dmis.org>,
Robert Richter <robert.richter@....com>
Subject: [PATCH 8/9] oprofile: fix lost sample counter
The number of lost samples could be greater than the number of
received samples. This patches fixes this. The implementation
introduces return values for add_sample() and add_code().
Signed-off-by: Robert Richter <robert.richter@....com>
---
drivers/oprofile/cpu_buffer.c | 83 ++++++++++++++++++++++++++---------------
1 files changed, 53 insertions(+), 30 deletions(-)
diff --git a/drivers/oprofile/cpu_buffer.c b/drivers/oprofile/cpu_buffer.c
index 7f7fc95..6109096 100644
--- a/drivers/oprofile/cpu_buffer.c
+++ b/drivers/oprofile/cpu_buffer.c
@@ -145,32 +145,31 @@ void end_cpu_work(void)
flush_scheduled_work();
}
-static inline void
+static inline int
add_sample(struct oprofile_cpu_buffer *cpu_buf,
unsigned long pc, unsigned long event)
{
struct op_entry entry;
+ int ret;
- if (cpu_buffer_write_entry(&entry))
- goto Error;
+ ret = cpu_buffer_write_entry(&entry);
+ if (ret)
+ return ret;
entry.sample->eip = pc;
entry.sample->event = event;
- if (cpu_buffer_write_commit(&entry))
- goto Error;
+ ret = cpu_buffer_write_commit(&entry);
+ if (ret)
+ return ret;
- return;
-
-Error:
- cpu_buf->sample_lost_overflow++;
- return;
+ return 0;
}
-static inline void
+static inline int
add_code(struct oprofile_cpu_buffer *buffer, unsigned long value)
{
- add_sample(buffer, ESCAPE_CODE, value);
+ return add_sample(buffer, ESCAPE_CODE, value);
}
/* This must be safe from any context. It's safe writing here
@@ -201,17 +200,25 @@ static int log_sample(struct oprofile_cpu_buffer *cpu_buf, unsigned long pc,
/* notice a switch from user->kernel or vice versa */
if (cpu_buf->last_is_kernel != is_kernel) {
cpu_buf->last_is_kernel = is_kernel;
- add_code(cpu_buf, is_kernel);
+ if (add_code(cpu_buf, is_kernel))
+ goto fail;
}
/* notice a task switch */
if (cpu_buf->last_task != task) {
cpu_buf->last_task = task;
- add_code(cpu_buf, (unsigned long)task);
+ if (add_code(cpu_buf, (unsigned long)task))
+ goto fail;
}
- add_sample(cpu_buf, pc, event);
+ if (add_sample(cpu_buf, pc, event))
+ goto fail;
+
return 1;
+
+fail:
+ cpu_buf->sample_lost_overflow++;
+ return 0;
}
static int oprofile_begin_trace(struct oprofile_cpu_buffer *cpu_buf)
@@ -266,37 +273,49 @@ void oprofile_add_ibs_sample(struct pt_regs * const regs,
int is_kernel = !user_mode(regs);
struct oprofile_cpu_buffer *cpu_buf = &__get_cpu_var(cpu_buffer);
struct task_struct *task;
+ int fail = 0;
cpu_buf->sample_received++;
/* notice a switch from user->kernel or vice versa */
if (cpu_buf->last_is_kernel != is_kernel) {
+ if (add_code(cpu_buf, is_kernel))
+ goto fail;
cpu_buf->last_is_kernel = is_kernel;
- add_code(cpu_buf, is_kernel);
}
/* notice a task switch */
if (!is_kernel) {
task = current;
if (cpu_buf->last_task != task) {
+ if (add_code(cpu_buf, (unsigned long)task))
+ goto fail;
cpu_buf->last_task = task;
- add_code(cpu_buf, (unsigned long)task);
}
}
- add_code(cpu_buf, ibs_code);
- add_sample(cpu_buf, ibs_sample[0], ibs_sample[1]);
- add_sample(cpu_buf, ibs_sample[2], ibs_sample[3]);
- add_sample(cpu_buf, ibs_sample[4], ibs_sample[5]);
+ fail = fail || add_code(cpu_buf, ibs_code);
+ fail = fail || add_sample(cpu_buf, ibs_sample[0], ibs_sample[1]);
+ fail = fail || add_sample(cpu_buf, ibs_sample[2], ibs_sample[3]);
+ fail = fail || add_sample(cpu_buf, ibs_sample[4], ibs_sample[5]);
if (ibs_code == IBS_OP_BEGIN) {
- add_sample(cpu_buf, ibs_sample[6], ibs_sample[7]);
- add_sample(cpu_buf, ibs_sample[8], ibs_sample[9]);
- add_sample(cpu_buf, ibs_sample[10], ibs_sample[11]);
+ fail = fail || add_sample(cpu_buf, ibs_sample[6], ibs_sample[7]);
+ fail = fail || add_sample(cpu_buf, ibs_sample[8], ibs_sample[9]);
+ fail = fail || add_sample(cpu_buf, ibs_sample[10], ibs_sample[11]);
}
+ if (fail)
+ goto fail;
+
if (backtrace_depth)
oprofile_ops.backtrace(regs, backtrace_depth);
+
+ return;
+
+fail:
+ cpu_buf->sample_lost_overflow++;
+ return;
}
#endif
@@ -318,13 +337,17 @@ void oprofile_add_trace(unsigned long pc)
* broken frame can give an eip with the same value as an
* escape code, abort the trace if we get it
*/
- if (pc == ESCAPE_CODE) {
- cpu_buf->tracing = 0;
- cpu_buf->backtrace_aborted++;
- return;
- }
+ if (pc == ESCAPE_CODE)
+ goto fail;
+
+ if (add_sample(cpu_buf, pc, 0))
+ goto fail;
- add_sample(cpu_buf, pc, 0);
+ return;
+fail:
+ cpu_buf->tracing = 0;
+ cpu_buf->backtrace_aborted++;
+ return;
}
/*
--
1.6.0.1
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists