numatop/0009-x86-Fix-clock-frequency-parsing.patch
Pingfan Liu bb8dcb4304 add x86 zen support
Signed-off-by: Pingfan Liu <piliu@redhat.com>
2023-09-19 09:14:49 +08:00

72 lines
2.1 KiB
Diff

From c149b054fe5b1851860fd01d54596ea75f5008d3 Mon Sep 17 00:00:00 2001
From: Sandipan Das <sandipan.das@amd.com>
Date: Wed, 13 Apr 2022 11:45:08 +0530
Subject: [PATCH 09/15] x86: Fix clock frequency parsing
AMD processors do not advertise a base clock frequency as
a part of the "model name" in /proc/cpuinfo. The parsing
must fail in order to let os_calibrate() determine clock
speed from cpufreq information or from TSC instead.
Since the parser fails to find "@", strcspn() returns the
length of the line instead and sscanf() ends up scanning
garbage values beyond the null terminator that match the
format specifier. To avoid this, add an additional check
that makes the condition fail if "@" is not found.
Fixes: eaeed92 ("Powerpc: Fix CPU% utilization for PowerVMs")
Signed-off-by: Sandipan Das <sandipan.das@amd.com>
---
x86/util.c | 19 ++++++++++++++-----
1 file changed, 14 insertions(+), 5 deletions(-)
diff --git a/x86/util.c b/x86/util.c
index fdff877..655a677 100644
--- a/x86/util.c
+++ b/x86/util.c
@@ -67,27 +67,36 @@ rdtsc(void)
/*
* Check the cpu name in proc info. Intel CPUs always have @ x.y
- * Ghz and that is the TSC frequency.
+ * GHz and that is the TSC frequency. AMD CPUs do not advertise
+ * clock frequency as a part of the model name.
*/
int
arch__cpuinfo_freq(double *freq, char *unit)
{
FILE *f;
char *line = NULL;
- size_t len = 0;
+ size_t idx, len = 0;
int ret = -1;
if ((f = fopen(CPUINFO_PATH, "r")) == NULL) {
return (-1);
}
- while (getline(&line, &len, f) > 0) {
+ while ((len = getline(&line, &len, f)) > 0) {
if (strncmp(line, "model name", sizeof ("model name") - 1) != 0) {
continue;
}
- if (sscanf(line + strcspn(line, "@") + 1, "%lf%10s",
- freq, unit) == 2) {
+ idx = strcspn(line, "@") + 1;
+
+ /*
+ * The model name will not change for other processors. So
+ * bail out if "@" is not found.
+ */
+ if (idx >= len)
+ break;
+
+ if (sscanf(line + idx, "%lf%10s", freq, unit) == 2) {
if (strcasecmp(unit, "GHz") == 0) {
*freq *= GHZ;
} else if (strcasecmp(unit, "Mhz") == 0) {
--
2.31.1