[PATCH v3 1/3] perf header: Fix HEADER_COMPRESSED validation for comp_mmap_len

[Ian Rogers <irogers@google.com>]

This commit updates process_compressed() to ignore comp_mmap_len == 0
when validating the compressed header. A zero size is valid and may
occur during testing.

Sashiko review flagged string.h was missing (preexisting problem) and
so I opportunistically fixed this and sorted the header files.

Signed-off-by: Ian Rogers <irogers@google.com>
Assisted-by: Antigravity:gemini-3.1-pro
---
 tools/perf/util/header.c | 79 +++++++++++++++++++++-------------------
 1 file changed, 42 insertions(+), 37 deletions(-)

diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c
index 7db7da090a1e..974ce1c926cd 100644
--- a/tools/perf/util/header.c
+++ b/tools/perf/util/header.c
@@ -1,65 +1,69 @@
 // SPDX-License-Identifier: GPL-2.0
+#include "header.h"
+
 #include <errno.h>
 #include <inttypes.h>
 #include <limits.h>
-#include "string2.h"
-#include <sys/param.h>
-#include <sys/types.h>
-#include <byteswap.h>
-#include <unistd.h>
-#include <regex.h>
 #include <stdio.h>
 #include <stdlib.h>
+#include <string.h>
+
+#include <asm/bug.h>
+#include <byteswap.h>
+#include <dirent.h>
+#include <linux/bitops.h>
 #include <linux/compiler.h>
-#include <linux/list.h>
+#include <linux/ctype.h>
 #include <linux/kernel.h>
-#include <linux/bitops.h>
+#include <linux/list.h>
 #include <linux/string.h>
 #include <linux/stringify.h>
+#include <linux/time64.h>
 #include <linux/zalloc.h>
+#include <regex.h>
+#include <sys/param.h>
 #include <sys/stat.h>
+#include <sys/types.h>
 #include <sys/utsname.h>
-#include <linux/time64.h>
-#include <dirent.h>
-#ifdef HAVE_LIBBPF_SUPPORT
-#include <bpf/libbpf.h>
-#endif
+#include <unistd.h>
+
+#include <api/fs/fs.h>
+#include <api/io_dir.h>
+#include <internal/lib.h>
 #include <perf/cpumap.h>
 #include <tools/libc_compat.h> // reallocarray
 
+#include "../perf.h"
+#include "bpf-event.h"
+#include "bpf-utils.h"
+#include "build-id.h"
+#include "cacheline.h"
+#include "clockid.h"
+#include "cpumap.h"
+#include "cputopo.h"
+#include "data.h"
+#include "debug.h"
 #include "dso.h"
 #include "evlist.h"
 #include "evsel.h"
-#include "util/evsel_fprintf.h"
-#include "header.h"
+#include "evsel_fprintf.h"
 #include "memswap.h"
-#include "trace-event.h"
-#include "session.h"
-#include "symbol.h"
-#include "debug.h"
-#include "cpumap.h"
 #include "pmu.h"
 #include "pmus.h"
-#include "vdso.h"
+#include "session.h"
 #include "strbuf.h"
-#include "build-id.h"
-#include "data.h"
-#include <api/fs/fs.h>
-#include <api/io_dir.h>
-#include "asm/bug.h"
-#include "tool.h"
-#include "../perf.h"
+#include "string2.h"
+#include "symbol.h"
 #include "time-utils.h"
+#include "tool.h"
+#include "trace-event.h"
 #include "units.h"
-#include "util/util.h" // perf_exe()
-#include "cputopo.h"
-#include "bpf-event.h"
-#include "bpf-utils.h"
-#include "clockid.h"
-#include "cacheline.h"
+#include "util.h" // perf_exe()
+#include "vdso.h"
 
-#include <linux/ctype.h>
-#include <internal/lib.h>
+#ifdef HAVE_LIBBPF_SUPPORT
+#include <bpf/libbpf.h>
+#endif
 
 #ifdef HAVE_LIBTRACEEVENT
 #include <event-parse.h>
@@ -3903,7 +3907,8 @@ static int process_compressed(struct feat_fd *ff,
 	 * checks decomp_len + sizeof(struct decomp) against SIZE_MAX
 	 * before allocating, which handles 32-bit safety.
 	 */
-	if (env->comp_mmap_len < 4096 || env->comp_mmap_len % 4096) {
+	if (env->comp_mmap_len &&
+	    (env->comp_mmap_len < 4096 || env->comp_mmap_len % 4096)) {
 		pr_err("Invalid HEADER_COMPRESSED: comp_mmap_len (%u) must be a 4K-aligned value >= 4096\n",
 		       env->comp_mmap_len);
 		return -1;
-- 
2.55.0.1007.g17ff1f9808-goog