[PATCH] tools/power/x86/turbostat: add NULL check after calloc()

[longlong yan]

Three calloc() calls in turbostat lack NULL return checks, leading to
potential NULL pointer dereferences on allocation failure:

1. rapl_perf_init(): the allocated `domain_visited` is used later via
   memset(domain_visited, 0, ...) without checking for NULL.

2. added_perf_counters_init_(): the allocated `domain_visited` is used
   later via memset() and domain_visited[next_domain] without checking
   for NULL.

3. pmt_add_counter(): the allocated `pcounter` is dereferenced
   immediately via strncpy(pcounter->name, ...) without checking for
   NULL.

Add NULL checks after each calloc(), using the same error handling
style already present in each function: err(-1, ...) for rapl_perf_init(),
errx(1, ...) for added_perf_counters_init_(), and return 1 for
pmt_add_counter().

Signed-off-by: longlong yan <yanlonglong@xxxxxxxxxx>
---
 tools/power/x86/turbostat/turbostat.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/tools/power/x86/turbostat/turbostat.c b/tools/power/x86/turbostat/turbostat.c
index 4ad7cb1df5c5..926dd1422fbe 100644
--- a/tools/power/x86/turbostat/turbostat.c
+++ b/tools/power/x86/turbostat/turbostat.c
@@ -8578,6 +8578,8 @@ void rapl_perf_init(void)
 {
 	const unsigned int num_domains = get_rapl_num_domains();
 	bool *domain_visited = calloc(num_domains, sizeof(bool));
+	if (!domain_visited)
+		err(-1, "calloc domain_visited");
 
 	rapl_counter_info_perdomain = calloc(num_domains, sizeof(*rapl_counter_info_perdomain));
 	if (rapl_counter_info_perdomain == NULL)
@@ -9942,6 +9944,8 @@ int added_perf_counters_init_(struct perf_counter_info *pinfo)
 	const size_t max_num_domains = MAX(topo.max_cpu_num + 1, MAX(topo.max_core_id + 1, topo.max_package_id + 1));
 
 	domain_visited = calloc(max_num_domains, sizeof(*domain_visited));
+	if (!domain_visited)
+		errx(1, "%s: alloc %s", __func__, "domain_visited");
 
 	while (pinfo) {
 		switch (pinfo->scope) {
@@ -10333,6 +10337,8 @@ int pmt_add_counter(unsigned int guid, unsigned int seq, const char *name, enum
 	pcounter = pmt_find_counter(*pmt_root, name);
 	if (!pcounter) {
 		pcounter = calloc(1, sizeof(*pcounter));
+		if (!pcounter)
+			return 1;
 		new_counter = true;
 	}
 
-- 
2.43.0