Avoid crash in min/max caculation when cpu#0 being offline

When cpu#0 is offline, atof(NULL) is called which causes
a segfault or endless loop depending on implementation
circumstances. So instead of implicitely assumping that the
first cpu is always available, do the presence checks for
all including the first one.

diff --git a/sys-utils/lscpu.c b/sys-utils/lscpu.c
index 6d1fde555e02d64067cdd71ca4ba7bf9e34156d3..2132511a5a8555088197033e867b82e1c18b4191 100644 (file)
--- a/sys-utils/lscpu.c
+++ b/sys-utils/lscpu.c
@@ -1108,10 +1108,10 @@ static char *
 cpu_max_mhz(struct lscpu_desc *desc, char *buf, size_t bufsz)
 {
        int i;
-       float cpu_freq = atof(desc->maxmhz[0]);
+       float cpu_freq = 0.0;
 
        if (desc->present) {
-               for (i = 1; i < desc->ncpuspos; i++) {
+               for (i = 0; i < desc->ncpuspos; i++) {
                        if (CPU_ISSET(real_cpu_num(desc, i), desc->present)
                            && desc->maxmhz[i]) {
                                float freq = atof(desc->maxmhz[i]);
@@ -1129,16 +1129,16 @@ cpu_max_mhz(struct lscpu_desc *desc, char *buf, size_t bufsz)
 static char *
 cpu_min_mhz(struct lscpu_desc *desc, char *buf, size_t bufsz)
 {
-        int i;
-        float cpu_freq = atof(desc->minmhz[0]);
+       int i;
+       float cpu_freq = -1.0;
 
        if (desc->present) {
-               for (i = 1; i < desc->ncpuspos; i++) {
+               for (i = 0; i < desc->ncpuspos; i++) {
                        if (CPU_ISSET(real_cpu_num(desc, i), desc->present)
                            && desc->minmhz[i]) {
                                float freq = atof(desc->minmhz[i]);
 
-                               if (freq < cpu_freq)
+                               if (cpu_freq < 0.0 || freq < cpu_freq)
                                        cpu_freq = freq;
                        }
                }