[PATCH v1 1/3] perf header: Fix HEADER_COMPRESSED validation for comp_mmap_len

[PATCH v1 1/3] perf header: Fix HEADER_COMPRESSED validation for comp_mmap_len

[Ian Rogers]

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 | 78 +++++++++++++++++++++-------------------
 1 file changed, 41 insertions(+), 37 deletions(-)

diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c
index 7db7da090a1e..bdd79d7542ef 100644
--- a/tools/perf/util/header.c
+++ b/tools/perf/util/header.c
@@ -1,65 +1,68 @@
 // 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 "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 +3906,8 @@ 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

[PATCH v1 2/3] perf header: Fix potential memory corruption in cpu_cache_level__read

[Ian Rogers]

strim may advance the pointer assigned to cache->size which causes
later frees to crash. Fix by performing the strim and then memmove-ing
the potentially shifted string back over the original string. The bug
was introduced by the transition from rtrim to strim, as rtrim
wouldn't move on the left.

Fixes: 13c230ab6e56 ("perf tools: Ditch rtrim(), use strim() from tools/lib")
Signed-off-by: Ian Rogers <irogers@google.com>
Assisted-by: Antigravity:gemini-3.1-pro
---
 tools/perf/util/header.c | 18 +++++++++++++++---
 1 file changed, 15 insertions(+), 3 deletions(-)

diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c
index bdd79d7542ef..78b16a098148 100644
--- a/tools/perf/util/header.c
+++ b/tools/perf/util/header.c
@@ -1267,7 +1267,11 @@ static int cpu_cache_level__read(struct cpu_cache_level *cache, u32 cpu, u16 lev
 		return -1;
 
 	cache->type[len] = 0;
-	cache->type = strim(cache->type);
+	{
+		char *trimmed = strim(cache->type);
+
+		memmove(cache->type, trimmed, strlen(trimmed) + 1);
+	}
 
 	scnprintf(file, PATH_MAX, "%s/size", path);
 	if (sysfs__read_str(file, &cache->size, &len)) {
@@ -1276,7 +1280,11 @@ static int cpu_cache_level__read(struct cpu_cache_level *cache, u32 cpu, u16 lev
 	}
 
 	cache->size[len] = 0;
-	cache->size = strim(cache->size);
+	{
+		char *trimmed = strim(cache->size);
+
+		memmove(cache->size, trimmed, strlen(trimmed) + 1);
+	}
 
 	scnprintf(file, PATH_MAX, "%s/shared_cpu_list", path);
 	if (sysfs__read_str(file, &cache->map, &len)) {
@@ -1286,7 +1294,11 @@ static int cpu_cache_level__read(struct cpu_cache_level *cache, u32 cpu, u16 lev
 	}
 
 	cache->map[len] = 0;
-	cache->map = strim(cache->map);
+	{
+		char *trimmed = strim(cache->map);
+
+		memmove(cache->map, trimmed, strlen(trimmed) + 1);
+	}
 	return 0;
 }
 
-- 
2.55.0.1007.g17ff1f9808-goog

[PATCH v1 3/3] perf header: Transition WARN macros to debug.h equivalents

[Ian Rogers]

Avoid a checkpatch.pl warning on the use of asm/bug.h by switching the
use of WARN macros to explicit tests and then using pr_warning from
debug.h.

Signed-off-by: Ian Rogers <irogers@google.com>
---
 tools/perf/util/header.c | 27 ++++++++++++++++++---------
 1 file changed, 18 insertions(+), 9 deletions(-)

diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c
index 78b16a098148..a3e6c334a289 100644
--- a/tools/perf/util/header.c
+++ b/tools/perf/util/header.c
@@ -8,7 +8,6 @@
 #include <stdlib.h>
 #include <string.h>
 
-#include <asm/bug.h>
 #include <byteswap.h>
 #include <dirent.h>
 #include <linux/bitops.h>
@@ -384,8 +383,10 @@ static int do_read_bitmap(struct feat_fd *ff, unsigned long **pset, u64 *psize)
 static int write_tracing_data(struct feat_fd *ff,
 			      struct evlist *evlist __maybe_unused)
 {
-	if (WARN(ff->buf, "Error: calling %s in pipe-mode.\n", __func__))
+	if (ff->buf) {
+		pr_warning("Error: calling %s in pipe-mode.\n", __func__);
 		return -1;
+	}
 
 #ifdef HAVE_LIBTRACEEVENT
 	return read_tracing_data(ff->fd, &evlist__core(evlist)->entries);
@@ -406,8 +407,10 @@ static int write_build_id(struct feat_fd *ff,
 	if (!perf_session__read_build_ids(session, true))
 		return -1;
 
-	if (WARN(ff->buf, "Error: calling %s in pipe-mode.\n", __func__))
+	if (ff->buf) {
+		pr_warning("Error: calling %s in pipe-mode.\n", __func__);
 		return -1;
+	}
 
 	err = perf_session__write_buildid_table(session, ff);
 	if (err < 0) {
@@ -1013,8 +1016,10 @@ static int write_auxtrace(struct feat_fd *ff,
 	struct perf_session *session;
 	int err;
 
-	if (WARN(ff->buf, "Error: calling %s in pipe-mode.\n", __func__))
+	if (ff->buf) {
+		pr_warning("Error: calling %s in pipe-mode.\n", __func__);
 		return -1;
+	}
 
 	session = container_of(ff->ph, struct perf_session, header);
 
@@ -1108,9 +1113,10 @@ static int write_dir_format(struct feat_fd *ff,
 	session = container_of(ff->ph, struct perf_session, header);
 	data = session->data;
 
-	if (WARN_ON(!perf_data__is_dir(data)))
+	if (!perf_data__is_dir(data)) {
+		pr_warning("Expected data to be a directory");
 		return -1;
-
+	}
 	return do_write(ff, &data->dir.version, sizeof(data->dir.version));
 }
 
@@ -3714,9 +3720,10 @@ static int process_dir_format(struct feat_fd *ff,
 	session = container_of(ff->ph, struct perf_session, header);
 	data = session->data;
 
-	if (WARN_ON(!perf_data__is_dir(data)))
+	if (!perf_data__is_dir(data)) {
+		pr_warning("Expected data to be a directory");
 		return -1;
-
+	}
 	return do_read_u64(ff, &data->dir.version);
 }
 
@@ -4394,8 +4401,10 @@ static int do_write_feat(struct feat_fd *ff, int type,
 		if (!feat_ops[type].write)
 			return -1;
 
-		if (WARN(ff->buf, "Error: calling %s in pipe-mode.\n", __func__))
+		if (ff->buf) {
+			pr_warning("Error: calling %s in pipe-mode.\n", __func__);
 			return -1;
+		}
 
 		(*p)->offset = lseek(ff->fd, 0, SEEK_CUR);
 
-- 
2.55.0.1007.g17ff1f9808-goog

Re: [PATCH v1 3/3] perf header: Transition WARN macros to debug.h equivalents

[sashiko-bot]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Low] Missing newline character at the end of the pr_warning format string.
--

commit 4a0b2ee01b018f0849023322af221ce512de09c8
Author: Ian Rogers <irogers@google.com>

perf header: Transition WARN macros to debug.h equivalents

This commit avoids a checkpatch.pl warning on the use of asm/bug.h by
switching the use of WARN macros to explicit tests and using pr_warning from
debug.h.

> diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c
> index 78b16a098148a..a3e6c334a2894 100644
> --- a/tools/perf/util/header.c
> +++ b/tools/perf/util/header.c
[ ... ]
> @@ -1108,9 +1113,10 @@ static int write_dir_format(struct feat_fd *ff,
>  	session = container_of(ff->ph, struct perf_session, header);
>  	data = session->data;
>  
> -	if (WARN_ON(!perf_data__is_dir(data)))
> +	if (!perf_data__is_dir(data)) {
> +		pr_warning("Expected data to be a directory");

[Severity: Low]
Does this pr_warning() need a newline character at the end of the format
string?

Unlike some kernel-space printk variants, the user-space pr_warning() does
not automatically append a newline. If perf attempts to write the directory
format but perf_data__is_dir(data) evaluates to false, this could result in
consecutive diagnostic messages, error logs, or the user's shell prompt
improperly concatenating to the end of this warning message.

>  		return -1;
> -
> +	}
>  	return do_write(ff, &data->dir.version, sizeof(data->dir.version));
>  }
[ ... ]
> @@ -3714,9 +3720,10 @@ static int process_dir_format(struct feat_fd *ff,
>  	session = container_of(ff->ph, struct perf_session, header);
>  	data = session->data;
>  
> -	if (WARN_ON(!perf_data__is_dir(data)))
> +	if (!perf_data__is_dir(data)) {
> +		pr_warning("Expected data to be a directory");

[Severity: Low]
Similarly here in process_dir_format(), should this warning string include a
trailing newline to prevent visual formatting glitches on the console when
processing a malformed directory format?

>  		return -1;
> -
> +	}
>  	return do_read_u64(ff, &data->dir.version);
>  }

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260910173715.2996571-1-irogers@google.com?part=3

Re: [PATCH v1 2/3] perf header: Fix potential memory corruption in cpu_cache_level__read

[sashiko-bot]

> strim may advance the pointer assigned to cache->size which causes
> later frees to crash. Fix by performing the strim and then memmove-ing
> the potentially shifted string back over the original string. The bug
> was introduced by the transition from rtrim to strim, as rtrim
> wouldn't move on the left.
> 
> Fixes: 13c230ab6e56 ("perf tools: Ditch rtrim(), use strim() from tools/lib")
> Signed-off-by: Ian Rogers <irogers@google.com>

Sashiko has reviewed this patch and found no issues. It looks great!

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260910173715.2996571-1-irogers@google.com?part=2

Re: [PATCH v1 1/3] perf header: Fix HEADER_COMPRESSED validation for comp_mmap_len

[sashiko-bot]

> 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>

Sashiko has reviewed this patch and found no issues. It looks great!

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260910173715.2996571-1-irogers@google.com?part=1

[PATCH v2 1/3] perf test x86: Fix missing __msan_unpoison

[Ian Rogers]

__msan_unpoison may need the sanitizer header including for its
definition.

Signed-off-by: Ian Rogers <irogers@google.com>
---
 tools/perf/arch/x86/tests/dwarf-unwind.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/tools/perf/arch/x86/tests/dwarf-unwind.c b/tools/perf/arch/x86/tests/dwarf-unwind.c
index 99d2b7ed016f..3c66dadcab75 100644
--- a/tools/perf/arch/x86/tests/dwarf-unwind.c
+++ b/tools/perf/arch/x86/tests/dwarf-unwind.c
@@ -8,6 +8,10 @@
 #include "debug.h"
 #include "tests/tests.h"
 
+#if defined(MEMORY_SANITIZER) && !defined(__msan_unpoison)
+# include <sanitizer/msan_interface.h>
+#endif
+
 #define STACK_SIZE 8192
 
 static int sample_ustack(struct perf_sample *sample,
-- 
2.55.0.1007.g17ff1f9808-goog

[PATCH v2 2/3] perf header: Fix HEADER_COMPRESSED validation for comp_mmap_len

[Ian Rogers]

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 | 78 +++++++++++++++++++++-------------------
 1 file changed, 41 insertions(+), 37 deletions(-)

diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c
index 7db7da090a1e..bdd79d7542ef 100644
--- a/tools/perf/util/header.c
+++ b/tools/perf/util/header.c
@@ -1,65 +1,68 @@
 // 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 "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 +3906,8 @@ 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

[PATCH v2 3/3] perf header: Fix potential memory corruption in cpu_cache_level__read

[Ian Rogers]

strim may advance the pointer assigned to cache->size which causes
later frees to crash. Fix by performing the strim and then memmove-ing
the potentially shifted string back over the original string. The bug
was introduced by the transition from rtrim to strim, as rtrim
wouldn't move on the left.

Fixes: 13c230ab6e56 ("perf tools: Ditch rtrim(), use strim() from tools/lib")
Signed-off-by: Ian Rogers <irogers@google.com>
Assisted-by: Antigravity:gemini-3.1-pro
---
 tools/perf/util/header.c | 18 +++++++++++++++---
 1 file changed, 15 insertions(+), 3 deletions(-)

diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c
index bdd79d7542ef..78b16a098148 100644
--- a/tools/perf/util/header.c
+++ b/tools/perf/util/header.c
@@ -1267,7 +1267,11 @@ static int cpu_cache_level__read(struct cpu_cache_level *cache, u32 cpu, u16 lev
 		return -1;
 
 	cache->type[len] = 0;
-	cache->type = strim(cache->type);
+	{
+		char *trimmed = strim(cache->type);
+
+		memmove(cache->type, trimmed, strlen(trimmed) + 1);
+	}
 
 	scnprintf(file, PATH_MAX, "%s/size", path);
 	if (sysfs__read_str(file, &cache->size, &len)) {
@@ -1276,7 +1280,11 @@ static int cpu_cache_level__read(struct cpu_cache_level *cache, u32 cpu, u16 lev
 	}
 
 	cache->size[len] = 0;
-	cache->size = strim(cache->size);
+	{
+		char *trimmed = strim(cache->size);
+
+		memmove(cache->size, trimmed, strlen(trimmed) + 1);
+	}
 
 	scnprintf(file, PATH_MAX, "%s/shared_cpu_list", path);
 	if (sysfs__read_str(file, &cache->map, &len)) {
@@ -1286,7 +1294,11 @@ static int cpu_cache_level__read(struct cpu_cache_level *cache, u32 cpu, u16 lev
 	}
 
 	cache->map[len] = 0;
-	cache->map = strim(cache->map);
+	{
+		char *trimmed = strim(cache->map);
+
+		memmove(cache->map, trimmed, strlen(trimmed) + 1);
+	}
 	return 0;
 }
 
-- 
2.55.0.1007.g17ff1f9808-goog

Re: [PATCH v2 3/3] perf header: Fix potential memory corruption in cpu_cache_level__read

[sashiko-bot]

> strim may advance the pointer assigned to cache->size which causes
> later frees to crash. Fix by performing the strim and then memmove-ing
> the potentially shifted string back over the original string. The bug
> was introduced by the transition from rtrim to strim, as rtrim
> wouldn't move on the left.
> 
> Fixes: 13c230ab6e56 ("perf tools: Ditch rtrim(), use strim() from tools/lib")
> Signed-off-by: Ian Rogers <irogers@google.com>

Sashiko has reviewed this patch and found no issues. It looks great!

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260910175634.3014018-1-irogers@google.com?part=3

Re: [PATCH v2 1/3] perf test x86: Fix missing __msan_unpoison

[sashiko-bot]

> __msan_unpoison may need the sanitizer header including for its
> definition.
> 
> Signed-off-by: Ian Rogers <irogers@google.com>

Sashiko has reviewed this patch and found no issues. It looks great!

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260910175634.3014018-1-irogers@google.com?part=1

Re: [PATCH v2 2/3] perf header: Fix HEADER_COMPRESSED validation for comp_mmap_len

[sashiko-bot]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Low] Removal of `../perf.h` leaves `MAX_NR_CPUS` undefined, breaking compilation.
--

commit 6870b0e134392a29ae6d615a0881f18783b3b995
Author: Ian Rogers <irogers@google.com>

perf header: Fix HEADER_COMPRESSED validation for comp_mmap_len

This commit updates process_compressed() to ignore a zero size for 
comp_mmap_len when validating the compressed header. It also opportunistically
sorts the header files and fixes a missing string.h inclusion.

> diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c
> index 7db7da090a1e0..bdd79d7542ef1 100644
> --- a/tools/perf/util/header.c
> +++ b/tools/perf/util/header.c
[ ... ]
> -#include "data.h"
> -#include <api/fs/fs.h>
> -#include <api/io_dir.h>
> -#include "asm/bug.h"
> -#include "tool.h"
> -#include "../perf.h"

[Severity: Low]
Does removing the include for perf.h cause a build failure?

It appears perf.h provides the definition for MAX_NR_CPUS, which is used
to size arrays in existing functions like build_cpu_domain_map() within this 
same file:

    char dname[DNAME_LEN], cpumask[MAX_NR_CPUS];
    struct domain_info *domain_info;
    struct cpu_domain_map **cd_map;
    char cpulist[MAX_NR_CPUS];

Without an alternative definition for MAX_NR_CPUS, the compiler fails to
resolve the size of these arrays.

[ ... ]

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260910175634.3014018-1-irogers@google.com?part=2

[PATCH v3 0/3] perf header: Fix memory corruption and unnecessary warning

[Ian Rogers]

Some minor fixes that have shown up during testing.

v3: Fix Sashiko include nit. Accidentally posted wrong 1st patch in v2 (sorry :-( )
v2: Fix missing newling for pr_warning:
https://lore.kernel.org/linux-perf-users/20260910175634.3014018-1-irogers@google.com/
v1:
https://lore.kernel.org/linux-perf-users/20260910173715.2996571-1-irogers@google.com/

Ian Rogers (3):
  perf header: Fix HEADER_COMPRESSED validation for comp_mmap_len
  perf header: Fix potential memory corruption in cpu_cache_level__read
  perf header: Transition WARN macros to debug.h equivalents

 tools/perf/util/header.c | 122 ++++++++++++++++++++++++---------------
 1 file changed, 74 insertions(+), 48 deletions(-)

-- 
2.55.0.1007.g17ff1f9808-goog

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

[Ian Rogers]

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

[PATCH v3 2/3] perf header: Fix potential memory corruption in cpu_cache_level__read

[Ian Rogers]

strim may advance the pointer assigned to cache->size which causes
later frees to crash. Fix by performing the strim and then memmove-ing
the potentially shifted string back over the original string. The bug
was introduced by the transition from rtrim to strim, as rtrim
wouldn't move on the left.

Fixes: 13c230ab6e56 ("perf tools: Ditch rtrim(), use strim() from tools/lib")
Signed-off-by: Ian Rogers <irogers@google.com>
Assisted-by: Antigravity:gemini-3.1-pro
---
 tools/perf/util/header.c | 18 +++++++++++++++---
 1 file changed, 15 insertions(+), 3 deletions(-)

diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c
index 974ce1c926cd..0a4236fc0293 100644
--- a/tools/perf/util/header.c
+++ b/tools/perf/util/header.c
@@ -1268,7 +1268,11 @@ static int cpu_cache_level__read(struct cpu_cache_level *cache, u32 cpu, u16 lev
 		return -1;
 
 	cache->type[len] = 0;
-	cache->type = strim(cache->type);
+	{
+		char *trimmed = strim(cache->type);
+
+		memmove(cache->type, trimmed, strlen(trimmed) + 1);
+	}
 
 	scnprintf(file, PATH_MAX, "%s/size", path);
 	if (sysfs__read_str(file, &cache->size, &len)) {
@@ -1277,7 +1281,11 @@ static int cpu_cache_level__read(struct cpu_cache_level *cache, u32 cpu, u16 lev
 	}
 
 	cache->size[len] = 0;
-	cache->size = strim(cache->size);
+	{
+		char *trimmed = strim(cache->size);
+
+		memmove(cache->size, trimmed, strlen(trimmed) + 1);
+	}
 
 	scnprintf(file, PATH_MAX, "%s/shared_cpu_list", path);
 	if (sysfs__read_str(file, &cache->map, &len)) {
@@ -1287,7 +1295,11 @@ static int cpu_cache_level__read(struct cpu_cache_level *cache, u32 cpu, u16 lev
 	}
 
 	cache->map[len] = 0;
-	cache->map = strim(cache->map);
+	{
+		char *trimmed = strim(cache->map);
+
+		memmove(cache->map, trimmed, strlen(trimmed) + 1);
+	}
 	return 0;
 }
 
-- 
2.55.0.1007.g17ff1f9808-goog

[PATCH v3 3/3] perf header: Transition WARN macros to debug.h equivalents

[Ian Rogers]

Avoid a checkpatch.pl warning on the use of asm/bug.h by switching the
use of WARN macros to explicit tests and then using pr_warning from
debug.h.

Signed-off-by: Ian Rogers <irogers@google.com>
---
 tools/perf/util/header.c | 27 ++++++++++++++++++---------
 1 file changed, 18 insertions(+), 9 deletions(-)

diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c
index 0a4236fc0293..c7f2c29f02b0 100644
--- a/tools/perf/util/header.c
+++ b/tools/perf/util/header.c
@@ -8,7 +8,6 @@
 #include <stdlib.h>
 #include <string.h>
 
-#include <asm/bug.h>
 #include <byteswap.h>
 #include <dirent.h>
 #include <linux/bitops.h>
@@ -385,8 +384,10 @@ static int do_read_bitmap(struct feat_fd *ff, unsigned long **pset, u64 *psize)
 static int write_tracing_data(struct feat_fd *ff,
 			      struct evlist *evlist __maybe_unused)
 {
-	if (WARN(ff->buf, "Error: calling %s in pipe-mode.\n", __func__))
+	if (ff->buf) {
+		pr_warning("Error: calling %s in pipe-mode.\n", __func__);
 		return -1;
+	}
 
 #ifdef HAVE_LIBTRACEEVENT
 	return read_tracing_data(ff->fd, &evlist__core(evlist)->entries);
@@ -407,8 +408,10 @@ static int write_build_id(struct feat_fd *ff,
 	if (!perf_session__read_build_ids(session, true))
 		return -1;
 
-	if (WARN(ff->buf, "Error: calling %s in pipe-mode.\n", __func__))
+	if (ff->buf) {
+		pr_warning("Error: calling %s in pipe-mode.\n", __func__);
 		return -1;
+	}
 
 	err = perf_session__write_buildid_table(session, ff);
 	if (err < 0) {
@@ -1014,8 +1017,10 @@ static int write_auxtrace(struct feat_fd *ff,
 	struct perf_session *session;
 	int err;
 
-	if (WARN(ff->buf, "Error: calling %s in pipe-mode.\n", __func__))
+	if (ff->buf) {
+		pr_warning("Error: calling %s in pipe-mode.\n", __func__);
 		return -1;
+	}
 
 	session = container_of(ff->ph, struct perf_session, header);
 
@@ -1109,9 +1114,10 @@ static int write_dir_format(struct feat_fd *ff,
 	session = container_of(ff->ph, struct perf_session, header);
 	data = session->data;
 
-	if (WARN_ON(!perf_data__is_dir(data)))
+	if (!perf_data__is_dir(data)) {
+		pr_warning("Expected data to be a directory\n");
 		return -1;
-
+	}
 	return do_write(ff, &data->dir.version, sizeof(data->dir.version));
 }
 
@@ -3715,9 +3721,10 @@ static int process_dir_format(struct feat_fd *ff,
 	session = container_of(ff->ph, struct perf_session, header);
 	data = session->data;
 
-	if (WARN_ON(!perf_data__is_dir(data)))
+	if (!perf_data__is_dir(data)) {
+		pr_warning("Expected data to be a directory\n");
 		return -1;
-
+	}
 	return do_read_u64(ff, &data->dir.version);
 }
 
@@ -4395,8 +4402,10 @@ static int do_write_feat(struct feat_fd *ff, int type,
 		if (!feat_ops[type].write)
 			return -1;
 
-		if (WARN(ff->buf, "Error: calling %s in pipe-mode.\n", __func__))
+		if (ff->buf) {
+			pr_warning("Error: calling %s in pipe-mode.\n", __func__);
 			return -1;
+		}
 
 		(*p)->offset = lseek(ff->fd, 0, SEEK_CUR);
 
-- 
2.55.0.1007.g17ff1f9808-goog

Re: [PATCH v3 3/3] perf header: Transition WARN macros to debug.h equivalents

[sashiko-bot]

> Avoid a checkpatch.pl warning on the use of asm/bug.h by switching the
> use of WARN macros to explicit tests and then using pr_warning from
> debug.h.
> 
> Signed-off-by: Ian Rogers <irogers@google.com>

Sashiko has reviewed this patch and found no issues. It looks great!

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260910211221.3154261-1-irogers@google.com?part=3

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

[sashiko-bot]

> 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>

Sashiko has reviewed this patch and found no issues. It looks great!

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260910211221.3154261-1-irogers@google.com?part=1

Re: [PATCH v3 2/3] perf header: Fix potential memory corruption in cpu_cache_level__read

[sashiko-bot]

> strim may advance the pointer assigned to cache->size which causes
> later frees to crash. Fix by performing the strim and then memmove-ing
> the potentially shifted string back over the original string. The bug
> was introduced by the transition from rtrim to strim, as rtrim
> wouldn't move on the left.
> 
> Fixes: 13c230ab6e56 ("perf tools: Ditch rtrim(), use strim() from tools/lib")
> Signed-off-by: Ian Rogers <irogers@google.com>

Sashiko has reviewed this patch and found no issues. It looks great!

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260910211221.3154261-1-irogers@google.com?part=2

Re: [PATCH v3 0/3] perf header: Fix memory corruption and unnecessary warning

[Arnaldo Carvalho de Melo]

On Thu, Sep 10, 2026 at 02:12:17PM -0700, Ian Rogers wrote:
> Some minor fixes that have shown up during testing.
> 
> v3: Fix Sashiko include nit. Accidentally posted wrong 1st patch in v2 (sorry :-( )
> v2: Fix missing newling for pr_warning:
> https://lore.kernel.org/linux-perf-users/20260910175634.3014018-1-irogers@google.com/
> v1:
> https://lore.kernel.org/linux-perf-users/20260910173715.2996571-1-irogers@google.com/

Thanks, applied to perf-tools-next, for v7.4.

- Arnaldo
 
> Ian Rogers (3):
>   perf header: Fix HEADER_COMPRESSED validation for comp_mmap_len
>   perf header: Fix potential memory corruption in cpu_cache_level__read
>   perf header: Transition WARN macros to debug.h equivalents
> 
>  tools/perf/util/header.c | 122 ++++++++++++++++++++++++---------------
>  1 file changed, 74 insertions(+), 48 deletions(-)
> 
> -- 
> 2.55.0.1007.g17ff1f9808-goog