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authorSang-Heon Jeon <ekffu200098@gmail.com>2026-08-24 01:18:14 +0900
committerJulia Lawall <Julia.Lawall@inria.fr>2026-08-23 22:12:11 +0200
commit2bd30b8dc75b823dd7bbef9d7bc68e1fd7ecee5c (patch)
treedcc4da1d99f17541c5590ac63c77da4bf372a4ab /tools/perf/util/cap.c
downloadlinux-stable-2bd30b8dc75b823dd7bbef9d7bc68e1fd7ecee5c.tar.gz
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coccinelle: alloc_cast: drop removed allocatorsgrafted
- pci_alloc_consistent() and pci_zalloc_consistent() were removed by commit 7968778914e5 ("PCI: Remove the deprecated "pci-dma-compat.h" API") - kmem_alloc() was removed by commit f078d4ea8276 ("xfs: convert kmem_alloc() to kmalloc()") - kmem_zalloc() was removed by commit 10634530f7ba ("xfs: convert kmem_zalloc() to kzalloc()") - kmem_zone_alloc() and kmem_zone_zalloc() were removed by commit bae633a4a283 ("xfs: remove xfs_zone_{alloc,zalloc} helpers") So drop them from the rules. No functional change. Signed-off-by: Sang-Heon Jeon <ekffu200098@gmail.com> Signed-off-by: Julia Lawall <Julia.Lawall@inria.fr>
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;
+}