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authorLinus Torvalds <torvalds@linux-foundation.org>2026-08-19 10:09:22 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2026-08-19 10:09:22 -0700
commitf4cdf7ca9a1fdcca413157df19753f388a5a224e (patch)
tree60a31895b2446cd7fa27514e8c2843534a0de0da /tools/perf/tests/dwarf-unwind.c
downloadlinux-stable-f4cdf7ca9a1fdcca413157df19753f388a5a224e.tar.gz
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Merge tag 'media/v7.3-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-mediagrafted
Pull media updates from Mauro Carvalho Chehab: - v4l2-core: added ISP statistics support and per-block validation - v4l2-core: Allow unknown HDR10 white point and luminance - New camera sensors: Sony IMX678 and IMX471m, Himax HM1092 IR sensor - New codec: Milos: VPU v2.0 codec support - isp driver: gained support for Dreamchip RPPX1 ISP framework - vsp1 driver: gained support for RZ/T2H and RZ/N2H - Novalake driver: gained CVS support for new NVL hardware - dvb-core: fix feed leak on failed DMX_ADD_PID - several driver fixes, cleanups and minor improvements * tag 'media/v7.3-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media: (308 commits) media: ipu-bridge: check all DMI entries when overriding sensor rotation media: v4l2-async: avoid deleting unlinked ASC entry on link error media: rzg2l-cru: Align bytesperline to hardware DMA stride requirement media: intel/ipu6: fix async notifier cleanup leak on parse error media: staging/ipu7: fix async notifier UAF on probe error path media: amd: isp4: fix self-deadlock in isp4sd_pwron_and_init() error path media: amd: isp4: release partial allocations in isp4if_alloc_fw_gpumem() media: rcar-isp: Fix VSPX reference leaks media: rcar-isp: Release ISPCORE resources media: i2c: imx415: Release runtime PM reference on VBLANK error media: i2c: imx415: Return test pattern write errors media: renesas: vsp1: Declare index variables in for loop statement media: renesas: vsp1: Make reset control optional to support platforms without a reset line media: dt-bindings: media: renesas,vsp1: Document RZ/T2H and RZ/N2H SoCs media: dt-bindings: media: renesas,fcp: Document RZ/T2H and RZ/N2H SoCs media: nxp: imx8-isi: Add additional 32-bit RGB format support media: nxp: imx8-isi: Add 16-bit raw Bayer format support media: nxp: imx8-isi: Implement per-stream reference counting for multiplexed streams media: nxp: imx8-isi: Use BIT_ULL() for 64-bit stream masks media: nxp: imx8-isi: Correct color map between V4L2 and ISI ...
Diffstat (limited to 'tools/perf/tests/dwarf-unwind.c')
-rw-r--r--tools/perf/tests/dwarf-unwind.c223
1 files changed, 223 insertions, 0 deletions
diff --git a/tools/perf/tests/dwarf-unwind.c b/tools/perf/tests/dwarf-unwind.c
new file mode 100644
index 000000000..9ed78d00f
--- /dev/null
+++ b/tools/perf/tests/dwarf-unwind.c
@@ -0,0 +1,223 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/compiler.h>
+#include <linux/types.h>
+#include <linux/zalloc.h>
+#include <inttypes.h>
+#include <limits.h>
+#include <unistd.h>
+#include "tests.h"
+#include "debug.h"
+#include "env.h"
+#include "machine.h"
+#include "event.h"
+#include "../util/unwind.h"
+#include "perf_regs.h"
+#include "map.h"
+#include "symbol.h"
+#include "thread.h"
+#include "callchain.h"
+
+/* For bsearch. We try to unwind functions in shared object. */
+#include <stdlib.h>
+
+/*
+ * The test will assert frames are on the stack but tail call optimizations lose
+ * the frame of the caller. Clang can disable this optimization on a called
+ * function but GCC currently (11/2020) lacks this attribute. The barrier is
+ * used to inhibit tail calls in these cases.
+ */
+#ifdef __has_attribute
+#if __has_attribute(disable_tail_calls)
+#define NO_TAIL_CALL_ATTRIBUTE __attribute__((disable_tail_calls))
+#define NO_TAIL_CALL_BARRIER
+#endif
+#endif
+#ifndef NO_TAIL_CALL_ATTRIBUTE
+#define NO_TAIL_CALL_ATTRIBUTE
+#define NO_TAIL_CALL_BARRIER __asm__ __volatile__("" : : : "memory");
+#endif
+
+/*
+ * We need to keep these functions global, despite the
+ * fact that they are used only locally in this object,
+ * in order to keep them around even if the binary is
+ * stripped. If they are gone, the unwind check for
+ * symbol fails.
+ */
+int test_dwarf_unwind__thread(struct thread *thread);
+int test_dwarf_unwind__compare(void *p1, void *p2);
+int test_dwarf_unwind__krava_3(struct thread *thread);
+int test_dwarf_unwind__krava_2(struct thread *thread);
+int test_dwarf_unwind__krava_1(struct thread *thread);
+int test__dwarf_unwind(struct test_suite *test, int subtest);
+
+#define MAX_STACK 8
+
+static int unwind_entry(struct unwind_entry *entry, void *arg)
+{
+ unsigned long *cnt = (unsigned long *) arg;
+ char *symbol = entry->ms.sym ? entry->ms.sym->name : NULL;
+ static const char *funcs[MAX_STACK] = {
+ "test__arch_unwind_sample",
+ "test_dwarf_unwind__thread",
+ "test_dwarf_unwind__compare",
+ "bsearch",
+ "test_dwarf_unwind__krava_3",
+ "test_dwarf_unwind__krava_2",
+ "test_dwarf_unwind__krava_1",
+ "test__dwarf_unwind"
+ };
+ /*
+ * The funcs[MAX_STACK] array index, based on the
+ * callchain order setup.
+ */
+ int idx = callchain_param.order == ORDER_CALLER ?
+ MAX_STACK - *cnt - 1 : *cnt;
+
+ if (*cnt >= MAX_STACK) {
+ pr_debug("failed: crossed the max stack value %d\n", MAX_STACK);
+ return -1;
+ }
+
+ if (!symbol) {
+ pr_debug("failed: got unresolved address 0x%" PRIx64 "\n",
+ entry->ip);
+ return -1;
+ }
+
+ (*cnt)++;
+ pr_debug("got: %s 0x%" PRIx64 ", expecting %s\n",
+ symbol, entry->ip, funcs[idx]);
+ return strcmp((const char *) symbol, funcs[idx]);
+}
+
+NO_TAIL_CALL_ATTRIBUTE noinline int test_dwarf_unwind__thread(struct thread *thread)
+{
+ struct perf_sample sample;
+ unsigned long cnt = 0;
+ int err = -1;
+
+ perf_sample__init(&sample, /*all=*/true);
+ if (test__arch_unwind_sample(&sample, thread)) {
+ pr_debug("failed to get unwind sample\n");
+ goto out;
+ }
+
+ err = unwind__get_entries(unwind_entry, &cnt, thread,
+ &sample, MAX_STACK, false);
+ if (err)
+ pr_debug("unwind failed\n");
+ else if (cnt != MAX_STACK) {
+ pr_debug("got wrong number of stack entries %lu != %d\n",
+ cnt, MAX_STACK);
+ err = -1;
+ }
+
+ out:
+ zfree(&sample.user_stack.data);
+ zfree(&sample.user_regs->regs);
+ perf_sample__exit(&sample);
+ return err;
+}
+
+static int global_unwind_retval = -INT_MAX;
+
+NO_TAIL_CALL_ATTRIBUTE noinline int test_dwarf_unwind__compare(void *p1, void *p2)
+{
+ /* Any possible value should be 'thread' */
+ struct thread *thread = *(struct thread **)p1;
+
+ if (global_unwind_retval == -INT_MAX) {
+ /* Call unwinder twice for both callchain orders. */
+ callchain_param.order = ORDER_CALLER;
+
+ global_unwind_retval = test_dwarf_unwind__thread(thread);
+ if (!global_unwind_retval) {
+ callchain_param.order = ORDER_CALLEE;
+ global_unwind_retval = test_dwarf_unwind__thread(thread);
+ }
+ }
+
+ return p1 - p2;
+}
+
+NO_TAIL_CALL_ATTRIBUTE noinline int test_dwarf_unwind__krava_3(struct thread *thread)
+{
+ struct thread *array[2] = {thread, thread};
+ void *fp = &bsearch;
+ /*
+ * make _bsearch a volatile function pointer to
+ * prevent potential optimization, which may expand
+ * bsearch and call compare directly from this function,
+ * instead of libc shared object.
+ */
+ void *(*volatile _bsearch)(void *, void *, size_t,
+ size_t, int (*)(void *, void *));
+
+ _bsearch = fp;
+ _bsearch(array, &thread, 2, sizeof(struct thread **),
+ test_dwarf_unwind__compare);
+ return global_unwind_retval;
+}
+
+NO_TAIL_CALL_ATTRIBUTE noinline int test_dwarf_unwind__krava_2(struct thread *thread)
+{
+ int ret;
+
+ ret = test_dwarf_unwind__krava_3(thread);
+ NO_TAIL_CALL_BARRIER;
+ return ret;
+}
+
+NO_TAIL_CALL_ATTRIBUTE noinline int test_dwarf_unwind__krava_1(struct thread *thread)
+{
+ int ret;
+
+ ret = test_dwarf_unwind__krava_2(thread);
+ NO_TAIL_CALL_BARRIER;
+ return ret;
+}
+
+noinline int test__dwarf_unwind(struct test_suite *test __maybe_unused,
+ int subtest __maybe_unused)
+{
+ struct perf_env host_env;
+ struct machine *machine;
+ struct thread *thread;
+ int err = -1;
+ pid_t pid = getpid();
+
+ callchain_param.record_mode = CALLCHAIN_DWARF;
+ dwarf_callchain_users = true;
+
+ perf_env__init(&host_env);
+ machine = machine__new_live(&host_env, /*kernel_maps=*/true, pid);
+ if (!machine) {
+ pr_err("Could not get machine\n");
+ goto out;
+ }
+
+ if (machine__create_kernel_maps(machine)) {
+ pr_err("Failed to create kernel maps\n");
+ goto out;
+ }
+
+ if (verbose > 1)
+ machine__fprintf(machine, stderr);
+
+ thread = machine__find_thread(machine, pid, pid);
+ if (!thread) {
+ pr_err("Could not get thread\n");
+ goto out;
+ }
+
+ err = test_dwarf_unwind__krava_1(thread);
+ thread__put(thread);
+
+ out:
+ machine__delete(machine);
+ perf_env__exit(&host_env);
+ return err;
+}
+
+DEFINE_SUITE("Test dwarf unwind", dwarf_unwind);