summaryrefslogtreecommitdiffstats
path: root/tools/perf/util/cap.c
diff options
context:
space:
mode:
authorKees Cook <kees+treewide@kernel.org>2026-09-02 15:31:14 -0700
committerKees Cook <kees@kernel.org>2026-09-04 21:37:00 -0700
commit3a2c4d55e32ad65efebdb6de44eef3bfa08bb49d (patch)
treec65086f9bdcd48c6360fb7cb4598bca084da1f32 /tools/perf/util/cap.c
downloadlinux-stable-3a2c4d55e32ad65efebdb6de44eef3bfa08bb49d.tar.gz
linux-stable-3a2c4d55e32ad65efebdb6de44eef3bfa08bb49d.zip
treewide: refresh kmalloc_obj() conversionsgrafted
This is another run of the Coccinelle script for converting kmalloc() family of allocations to kmalloc_obj() via the existing rules in scripts/coccinelle/api/kmalloc_objs.cocci This catches both the set of kmalloc() uses added since the first kmalloc_obj() conversions in v7.0 and adds a large group missed in the first pass due to Coccinelle not interacting well with the cleanup.h scoped_...() family of macros[1]. I worked around this with spatch's "--macro-file" argument to a file with all the scoped_...() macros mapped to Coccinelle's YACFE_ITERATOR[2] as that was the closest viable control flow indicator I could find. Build tested allmodconfig on x86, arm64, arm, loongarch, mips, powerpc, riscv, and s390 with no new warnings. Link: https://lore.kernel.org/lkml/202609021314.8A9C0B8@keescook/ [1] Link: https://github.com/coccinelle/coccinelle/blob/master/standard.h [2] Signed-off-by: Kees Cook <kees+treewide@kernel.org>
Diffstat (limited to 'tools/perf/util/cap.c')
-rw-r--r--tools/perf/util/cap.c46
1 files changed, 46 insertions, 0 deletions
diff --git a/tools/perf/util/cap.c b/tools/perf/util/cap.c
new file mode 100644
index 000000000..272bd8255
--- /dev/null
+++ b/tools/perf/util/cap.c
@@ -0,0 +1,46 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Capability utilities
+ */
+
+#include "cap.h"
+#include "debug.h"
+#include <errno.h>
+#include <string.h>
+#include <sys/syscall.h>
+#include <unistd.h>
+
+#define MAX_LINUX_CAPABILITY_U32S _LINUX_CAPABILITY_U32S_3
+
+bool perf_cap__capable(int cap)
+{
+ struct __user_cap_header_struct header = {
+ .version = _LINUX_CAPABILITY_VERSION_3,
+ .pid = 0,
+ };
+ struct __user_cap_data_struct data[MAX_LINUX_CAPABILITY_U32S] = {};
+ __u32 cap_val;
+
+ while (syscall(SYS_capget, &header, &data[0]) == -1) {
+ /* Retry, first attempt has set the header.version correctly. */
+ if (errno == EINVAL && header.version != _LINUX_CAPABILITY_VERSION_3 &&
+ header.version == _LINUX_CAPABILITY_VERSION_1)
+ continue;
+
+ pr_debug2("capget syscall failed (%m) fall back on root check\n");
+ return geteuid() == 0;
+ }
+
+ /* Extract the relevant capability bit. */
+ if (cap >= 32) {
+ if (header.version == _LINUX_CAPABILITY_VERSION_3) {
+ cap_val = data[1].effective;
+ } else {
+ /* Capability beyond 32 is requested but only 32 are supported. */
+ return false;
+ }
+ } else {
+ cap_val = data[0].effective;
+ }
+ return (cap_val & (1 << (cap & 0x1f))) != 0;
+}