perf: Always feature test reallocarray

This is also used in util/comm.c now, so instead of selectively doing
the feature test, always do it. If it's ever used anywhere else it's
less likely to cause another build failure.

This doesn't remove the need to manually include libc_compat.h, and
missing that will still cause an error for glibc < 2.26. There isn't a
way to fix that without poisoning reallocarray like libbpf did, but that
has other downsides like making memory debugging tools less useful. So
for Perf keep it like this and we'll have to fix up any missed includes.

Fixes the following build error:

  util/comm.c:152:31: error: implicit declaration of function
                      'reallocarray' [-Wimplicit-function-declaration]
  152 |                         tmp = reallocarray(comm_strs->strs,
      |                               ^~~~~~~~~~~~

Fixes: 13ca628716c6 ("perf comm: Add reference count checking to 'struct comm_str'")
Reported-by: Ali Utku Selen <ali.utku.selen@arm.com>
Signed-off-by: James Clark <james.clark@linaro.org>
Reviewed-by: Ian Rogers <irogers@google.com>
Link: https://lore.kernel.org/r/20250129154405.777533-1-james.clark@linaro.org
Signed-off-by: Namhyung Kim <namhyung@kernel.org>

diff --git a/tools/perf/Makefile.config b/tools/perf/Makefile.config
index a148ca9efca912c588d470335a5a13afeb758206..23dbb6bb91cf85bbb997ca06e4b6ea22f2664d18 100644 (file)
--- a/tools/perf/Makefile.config
+++ b/tools/perf/Makefile.config
@@ -497,13 +497,14 @@ ifeq ($(feature-setns), 1)
   $(call detected,CONFIG_SETNS)
 endif
 
+ifeq ($(feature-reallocarray), 0)
+  CFLAGS += -DCOMPAT_NEED_REALLOCARRAY
+endif
+
 ifdef CORESIGHT
   $(call feature_check,libopencsd)
   ifeq ($(feature-libopencsd), 1)
     CFLAGS += -DHAVE_CSTRACE_SUPPORT $(LIBOPENCSD_CFLAGS)
-    ifeq ($(feature-reallocarray), 0)
-      CFLAGS += -DCOMPAT_NEED_REALLOCARRAY
-    endif
     LDFLAGS += $(LIBOPENCSD_LDFLAGS)
     EXTLIBS += $(OPENCSDLIBS)
     $(call detected,CONFIG_LIBOPENCSD)
@@ -1103,9 +1104,6 @@ ifndef NO_AUXTRACE
   ifndef NO_AUXTRACE
     $(call detected,CONFIG_AUXTRACE)
     CFLAGS += -DHAVE_AUXTRACE_SUPPORT
-    ifeq ($(feature-reallocarray), 0)
-      CFLAGS += -DCOMPAT_NEED_REALLOCARRAY
-    endif
   endif
 endif
 

diff --git a/tools/perf/util/comm.c b/tools/perf/util/comm.c
index 49b79cf0c5cc513bf66d160413cdcca40317b05d..8aa456d7c2cd2d74f575e61594098cb571199370 100644 (file)
--- a/tools/perf/util/comm.c
+++ b/tools/perf/util/comm.c
@@ -5,6 +5,8 @@
 #include <internal/rc_check.h>
 #include <linux/refcount.h>
 #include <linux/zalloc.h>
+#include <tools/libc_compat.h> // reallocarray
+
 #include "rwsem.h"
 
 DECLARE_RC_STRUCT(comm_str) {