summaryrefslogtreecommitdiff
path: root/tools/perf/util/symbol-elf.c
diff options
context:
space:
mode:
authorLinus Torvalds <torvalds@linux-foundation.org>2024-03-15 02:31:23 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2024-03-15 02:31:23 +0300
commit1bbeaf83dd7b5e3628b98bec66ff8fe2646e14aa (patch)
treea391eed8ae206613b48e02e56e6ad5c4432d8767 /tools/perf/util/symbol-elf.c
parent63bd30f249dcf0a7ce16967935cecee8feec24bb (diff)
parent0f66dfe7b91d2743cc71dfff37af503215b204ef (diff)
downloadlinux-1bbeaf83dd7b5e3628b98bec66ff8fe2646e14aa.tar.xz
Merge tag 'perf-tools-for-v6.9-2024-03-13' of git://git.kernel.org/pub/scm/linux/kernel/git/perf/perf-tools
Pull perf tools updates from Namhyung Kim: "perf stat: - Support new 'cluster' aggregation mode for shared resources depending on the hardware configuration: $ sudo perf stat -a --per-cluster -e cycles,instructions sleep 1 Performance counter stats for 'system wide': S0-D0-CLS0 2 85,051,822 cycles S0-D0-CLS0 2 73,909,908 instructions # 0.87 insn per cycle S0-D0-CLS2 2 93,365,918 cycles S0-D0-CLS2 2 83,006,158 instructions # 0.89 insn per cycle S0-D0-CLS4 2 104,157,523 cycles S0-D0-CLS4 2 53,234,396 instructions # 0.51 insn per cycle S0-D0-CLS6 2 65,891,079 cycles S0-D0-CLS6 2 41,478,273 instructions # 0.63 insn per cycle 1.002407989 seconds time elapsed - Various fixes and cleanups for event metrics including NaN handling perf script: - Use libcapstone if available to disassemble the instructions. This enables 'perf script -F disasm' and 'perf script --insn-trace=disasm' (for Intel-PT): $ perf script -F event,ip,disasm cycles:P: ffffffffa988d428 wrmsr cycles:P: ffffffffa9839d25 movq %rax, %r14 cycles:P: ffffffffa9cdcaf0 endbr64 cycles:P: ffffffffa988d428 wrmsr cycles:P: ffffffffa988d428 wrmsr cycles:P: ffffffffaa401f86 iretq cycles:P: ffffffffa99c4de5 movq 0x30(%rcx), %r8 cycles:P: ffffffffa988d428 wrmsr cycles:P: ffffffffaa401f86 iretq cycles:P: ffffffffa9907983 movl 0x68(%rbx), %eax cycles:P: ffffffffa988d428 wrmsr - Expose sample ID / stream ID to python scripts perf test: - Add more perf test cases from Redhat internal test suites. This time it adds the base infra and a few perf probe tests. More to come. :) - Add 'perf test -p' for parallel execution and fix some issues found by the parallel test - Support symbol test to print symbols in given (active) module: $ perf test -F -v Symbols --dso /lib/modules/$(uname -r)/kernel/fs/ext4/ext4.ko --- start --- Testing /lib/modules/6.5.13-1rodete2-amd64/kernel/fs/ext4/ext4.ko Overlapping symbols: 7a990-7a9a0 l __pfx_ext4_exit_fs 7a990-7a9a0 g __pfx_cleanup_module Overlapping symbols: 7a9a0-7aa1c l ext4_exit_fs 7a9a0-7aa1c g cleanup_module ... JSON metric updates: - A new round of Intel metric updates - Support Power11 PVR (compatible to Power10) - Fix cache latency events on Zen 4 to set SliceId properly Internal: - Fix reference counting for 'map' data structure, tireless work from Ian! - More memory optimization for struct thread and annotate histogram. Now, 'perf report' (TUI) and 'perf annotate' should be much lighter-weight in terms of memory footprint - Support cross-arch perf register access. Clean up the build configuration so that it can detect arch-register support at runtime. This can allow to parse register data in sample which was recorded in a different arch Others: - Sync task state in 'perf sched' to kernel using trace event fields. The task states have been changed so tools cannot assume a fixed encoding - Clean up 'perf mem' to generalize the arch-specific events - Add support for local and global variables to data type profiling. This would increase the success rate of type resolution with DWARF - Add short option -H for --hierarchy in 'perf report' and 'perf top'" * tag 'perf-tools-for-v6.9-2024-03-13' of git://git.kernel.org/pub/scm/linux/kernel/git/perf/perf-tools: (154 commits) perf annotate: Add comments in the data structures perf annotate: Remove sym_hist.addr[] array perf annotate: Calculate instruction overhead using hashmap perf annotate: Add a hashmap for symbol histogram perf threads: Reduce table size from 256 to 8 perf threads: Switch from rbtree to hashmap perf threads: Move threads to its own files perf machine: Move machine's threads into its own abstraction perf machine: Move fprintf to for_each loop and a callback perf trace: Ignore thread hashing in summary perf report: Sort child tasks by tid perf vendor events amd: Fix Zen 4 cache latency events perf version: Display availability of OpenCSD support perf vendor events intel: Add umasks/occ_sel to PCU events. perf map: Fix map reference count issues libperf evlist: Avoid out-of-bounds access perf lock contention: Account contending locks too perf metrics: Fix segv for metrics with no events perf metrics: Fix metric matching perf pmu: Fix a potential memory leak in perf_pmu__lookup() ...
Diffstat (limited to 'tools/perf/util/symbol-elf.c')
-rw-r--r--tools/perf/util/symbol-elf.c79
1 files changed, 76 insertions, 3 deletions
diff --git a/tools/perf/util/symbol-elf.c b/tools/perf/util/symbol-elf.c
index 4b934ed3bfd1..0b91f813c4fa 100644
--- a/tools/perf/util/symbol-elf.c
+++ b/tools/perf/util/symbol-elf.c
@@ -23,6 +23,7 @@
#include <linux/ctype.h>
#include <linux/kernel.h>
#include <linux/zalloc.h>
+#include <linux/string.h>
#include <symbol/kallsyms.h>
#include <internal/lib.h>
@@ -1329,6 +1330,58 @@ out_close:
return -1;
}
+static bool is_exe_text(int flags)
+{
+ return (flags & (SHF_ALLOC | SHF_EXECINSTR)) == (SHF_ALLOC | SHF_EXECINSTR);
+}
+
+/*
+ * Some executable module sections like .noinstr.text might be laid out with
+ * .text so they can use the same mapping (memory address to file offset).
+ * Check if that is the case. Refer to kernel layout_sections(). Return the
+ * maximum offset.
+ */
+static u64 max_text_section(Elf *elf, GElf_Ehdr *ehdr)
+{
+ Elf_Scn *sec = NULL;
+ GElf_Shdr shdr;
+ u64 offs = 0;
+
+ /* Doesn't work for some arch */
+ if (ehdr->e_machine == EM_PARISC ||
+ ehdr->e_machine == EM_ALPHA)
+ return 0;
+
+ /* ELF is corrupted/truncated, avoid calling elf_strptr. */
+ if (!elf_rawdata(elf_getscn(elf, ehdr->e_shstrndx), NULL))
+ return 0;
+
+ while ((sec = elf_nextscn(elf, sec)) != NULL) {
+ char *sec_name;
+
+ if (!gelf_getshdr(sec, &shdr))
+ break;
+
+ if (!is_exe_text(shdr.sh_flags))
+ continue;
+
+ /* .init and .exit sections are not placed with .text */
+ sec_name = elf_strptr(elf, ehdr->e_shstrndx, shdr.sh_name);
+ if (!sec_name ||
+ strstarts(sec_name, ".init") ||
+ strstarts(sec_name, ".exit"))
+ break;
+
+ /* Must be next to previous, assumes .text is first */
+ if (offs && PERF_ALIGN(offs, shdr.sh_addralign ?: 1) != shdr.sh_offset)
+ break;
+
+ offs = shdr.sh_offset + shdr.sh_size;
+ }
+
+ return offs;
+}
+
/**
* ref_reloc_sym_not_found - has kernel relocation symbol been found.
* @kmap: kernel maps and relocation reference symbol
@@ -1368,7 +1421,8 @@ static int dso__process_kernel_symbol(struct dso *dso, struct map *map,
struct maps *kmaps, struct kmap *kmap,
struct dso **curr_dsop, struct map **curr_mapp,
const char *section_name,
- bool adjust_kernel_syms, bool kmodule, bool *remap_kernel)
+ bool adjust_kernel_syms, bool kmodule, bool *remap_kernel,
+ u64 max_text_sh_offset)
{
struct dso *curr_dso = *curr_dsop;
struct map *curr_map;
@@ -1424,6 +1478,17 @@ static int dso__process_kernel_symbol(struct dso *dso, struct map *map,
if (!kmap)
return 0;
+ /*
+ * perf does not record module section addresses except for .text, but
+ * some sections can use the same mapping as .text.
+ */
+ if (kmodule && adjust_kernel_syms && is_exe_text(shdr->sh_flags) &&
+ shdr->sh_offset <= max_text_sh_offset) {
+ *curr_mapp = map;
+ *curr_dsop = dso;
+ return 0;
+ }
+
snprintf(dso_name, sizeof(dso_name), "%s%s", dso->short_name, section_name);
curr_map = maps__find_by_name(kmaps, dso_name);
@@ -1470,8 +1535,10 @@ static int dso__process_kernel_symbol(struct dso *dso, struct map *map,
dso__set_loaded(curr_dso);
*curr_mapp = curr_map;
*curr_dsop = curr_dso;
- } else
+ } else {
*curr_dsop = map__dso(curr_map);
+ map__put(curr_map);
+ }
return 0;
}
@@ -1497,6 +1564,7 @@ dso__load_sym_internal(struct dso *dso, struct map *map, struct symsrc *syms_ss,
Elf *elf;
int nr = 0;
bool remap_kernel = false, adjust_kernel_syms = false;
+ u64 max_text_sh_offset = 0;
if (kmap && !kmaps)
return -1;
@@ -1584,6 +1652,10 @@ dso__load_sym_internal(struct dso *dso, struct map *map, struct symsrc *syms_ss,
remap_kernel = true;
adjust_kernel_syms = dso->adjust_symbols;
}
+
+ if (kmodule && adjust_kernel_syms)
+ max_text_sh_offset = max_text_section(runtime_ss->elf, &runtime_ss->ehdr);
+
elf_symtab__for_each_symbol(syms, nr_syms, idx, sym) {
struct symbol *f;
const char *elf_name = elf_sym__name(&sym, symstrs);
@@ -1673,7 +1745,8 @@ dso__load_sym_internal(struct dso *dso, struct map *map, struct symsrc *syms_ss,
if (dso->kernel) {
if (dso__process_kernel_symbol(dso, map, &sym, &shdr, kmaps, kmap, &curr_dso, &curr_map,
- section_name, adjust_kernel_syms, kmodule, &remap_kernel))
+ section_name, adjust_kernel_syms, kmodule,
+ &remap_kernel, max_text_sh_offset))
goto out_elf_end;
} else if ((used_opd && runtime_ss->adjust_symbols) ||
(!used_opd && syms_ss->adjust_symbols)) {