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authorLinus Torvalds <torvalds@linux-foundation.org>2011-01-06 10:17:26 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2011-01-06 10:17:26 -0800
commit28d9bfc37c861aa9c8386dff1ac7e9a10e5c5162 (patch)
tree85bcc2db18ff20e380a40aba375e70d14c2671b4 /arch/x86/kernel/alternative.c
parentf3b0cfa9b017a9d4686c9b14b908a1685f97a077 (diff)
parent4b95f135f606c87e4056b6d7fd3c5781c818858b (diff)
downloadop-kernel-dev-28d9bfc37c861aa9c8386dff1ac7e9a10e5c5162.zip
op-kernel-dev-28d9bfc37c861aa9c8386dff1ac7e9a10e5c5162.tar.gz
Merge branch 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (146 commits) tools, perf: Documentation for the power events API perf: Add calls to suspend trace point perf script: Make some lists static perf script: Use the default lost event handler perf session: Warn about errors when processing pipe events too perf tools: Fix perf_event.h header usage perf test: Clarify some error reports in the open syscall test x86, NMI: Add touch_nmi_watchdog to io_check_error delay x86: Avoid calling arch_trigger_all_cpu_backtrace() at the same time x86: Only call smp_processor_id in non-preempt cases perf timechart: Adjust perf timechart to the new power events perf: Clean up power events by introducing new, more generic ones perf: Do not export power_frequency, but power_start event perf test: Add test for counting open syscalls perf evsel: Auto allocate resources needed for some methods perf evsel: Use {cpu,thread}_map to shorten list of parameters perf tools: Refactor all_tids to hold nr and the map perf tools: Refactor cpumap to hold nr and the map perf evsel: Introduce per cpu and per thread open helpers perf evsel: Steal the counter reading routines from stat ...
Diffstat (limited to 'arch/x86/kernel/alternative.c')
-rw-r--r--arch/x86/kernel/alternative.c49
1 files changed, 40 insertions, 9 deletions
diff --git a/arch/x86/kernel/alternative.c b/arch/x86/kernel/alternative.c
index 5079f24..553d0b0 100644
--- a/arch/x86/kernel/alternative.c
+++ b/arch/x86/kernel/alternative.c
@@ -591,17 +591,21 @@ static atomic_t stop_machine_first;
static int wrote_text;
struct text_poke_params {
- void *addr;
- const void *opcode;
- size_t len;
+ struct text_poke_param *params;
+ int nparams;
};
static int __kprobes stop_machine_text_poke(void *data)
{
struct text_poke_params *tpp = data;
+ struct text_poke_param *p;
+ int i;
if (atomic_dec_and_test(&stop_machine_first)) {
- text_poke(tpp->addr, tpp->opcode, tpp->len);
+ for (i = 0; i < tpp->nparams; i++) {
+ p = &tpp->params[i];
+ text_poke(p->addr, p->opcode, p->len);
+ }
smp_wmb(); /* Make sure other cpus see that this has run */
wrote_text = 1;
} else {
@@ -610,8 +614,12 @@ static int __kprobes stop_machine_text_poke(void *data)
smp_mb(); /* Load wrote_text before following execution */
}
- flush_icache_range((unsigned long)tpp->addr,
- (unsigned long)tpp->addr + tpp->len);
+ for (i = 0; i < tpp->nparams; i++) {
+ p = &tpp->params[i];
+ flush_icache_range((unsigned long)p->addr,
+ (unsigned long)p->addr + p->len);
+ }
+
return 0;
}
@@ -631,10 +639,13 @@ static int __kprobes stop_machine_text_poke(void *data)
void *__kprobes text_poke_smp(void *addr, const void *opcode, size_t len)
{
struct text_poke_params tpp;
+ struct text_poke_param p;
- tpp.addr = addr;
- tpp.opcode = opcode;
- tpp.len = len;
+ p.addr = addr;
+ p.opcode = opcode;
+ p.len = len;
+ tpp.params = &p;
+ tpp.nparams = 1;
atomic_set(&stop_machine_first, 1);
wrote_text = 0;
/* Use __stop_machine() because the caller already got online_cpus. */
@@ -642,6 +653,26 @@ void *__kprobes text_poke_smp(void *addr, const void *opcode, size_t len)
return addr;
}
+/**
+ * text_poke_smp_batch - Update instructions on a live kernel on SMP
+ * @params: an array of text_poke parameters
+ * @n: the number of elements in params.
+ *
+ * Modify multi-byte instruction by using stop_machine() on SMP. Since the
+ * stop_machine() is heavy task, it is better to aggregate text_poke requests
+ * and do it once if possible.
+ *
+ * Note: Must be called under get_online_cpus() and text_mutex.
+ */
+void __kprobes text_poke_smp_batch(struct text_poke_param *params, int n)
+{
+ struct text_poke_params tpp = {.params = params, .nparams = n};
+
+ atomic_set(&stop_machine_first, 1);
+ wrote_text = 0;
+ stop_machine(stop_machine_text_poke, (void *)&tpp, NULL);
+}
+
#if defined(CONFIG_DYNAMIC_FTRACE) || defined(HAVE_JUMP_LABEL)
#ifdef CONFIG_X86_64
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