Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull perf updates from Thomas Gleixner:
 "Kernel:
   - Improve kallsyms coverage
   - Add x86 entry trampolines to kcore
   - Fix ARM SPE handling
   - Correct PPC event post processing

  Tools:
   - Make the build system more robust
   - Small fixes and enhancements all over the place
   - Update kernel ABI header copies
   - Preparatory work for converting libtraceevnt to a shared library
   - License cleanups"

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (100 commits)
  tools arch: Update arch/x86/lib/memcpy_64.S copy used in 'perf bench mem memcpy'
  tools arch x86: Update tools's copy of cpufeatures.h
  perf python: Fix pyrf_evlist__read_on_cpu() interface
  perf mmap: Store real cpu number in 'struct perf_mmap'
  perf tools: Remove ext from struct kmod_path
  perf tools: Add gzip_is_compressed function
  perf tools: Add lzma_is_compressed function
  perf tools: Add is_compressed callback to compressions array
  perf tools: Move the temp file processing into decompress_kmodule
  perf tools: Use compression id in decompress_kmodule()
  perf tools: Store compression id into struct dso
  perf tools: Add compression id into 'struct kmod_path'
  perf tools: Make is_supported_compression() static
  perf tools: Make decompress_to_file() function static
  perf tools: Get rid of dso__needs_decompress() call in __open_dso()
  perf tools: Get rid of dso__needs_decompress() call in symbol__disassemble()
  perf tools: Get rid of dso__needs_decompress() call in read_object_code()
  tools lib traceevent: Change to SPDX License format
  perf llvm: Allow passing options to llc in addition to clang
  perf parser: Improve error message for PMU address filters
  ...

1 files changed, 37 insertions, 14 deletions

diff --git a/kernel/kallsyms.c b/kernel/kallsyms.c
index a23e21ada81b..02a0b01380d8 100644
--- a/kernel/kallsyms.c
+++ b/kernel/kallsyms.c
@@ -432,6 +432,7 @@ int sprint_backtrace(char *buffer, unsigned long address)
 /* To avoid using get_symbol_offset for every symbol, we carry prefix along. */
 struct kallsym_iter {
 	loff_t pos;
+	loff_t pos_arch_end;
 	loff_t pos_mod_end;
 	loff_t pos_ftrace_mod_end;
 	unsigned long value;
@@ -443,9 +444,29 @@ struct kallsym_iter {
 	int show_value;
 };
 
+int __weak arch_get_kallsym(unsigned int symnum, unsigned long *value,
+			    char *type, char *name)
+{
+	return -EINVAL;
+}
+
+static int get_ksymbol_arch(struct kallsym_iter *iter)
+{
+	int ret = arch_get_kallsym(iter->pos - kallsyms_num_syms,
+				   &iter->value, &iter->type,
+				   iter->name);
+
+	if (ret < 0) {
+		iter->pos_arch_end = iter->pos;
+		return 0;
+	}
+
+	return 1;
+}
+
 static int get_ksymbol_mod(struct kallsym_iter *iter)
 {
-	int ret = module_get_kallsym(iter->pos - kallsyms_num_syms,
+	int ret = module_get_kallsym(iter->pos - iter->pos_arch_end,
 				     &iter->value, &iter->type,
 				     iter->name, iter->module_name,
 				     &iter->exported);
@@ -501,32 +522,34 @@ static void reset_iter(struct kallsym_iter *iter, loff_t new_pos)
 	iter->nameoff = get_symbol_offset(new_pos);
 	iter->pos = new_pos;
 	if (new_pos == 0) {
+		iter->pos_arch_end = 0;
 		iter->pos_mod_end = 0;
 		iter->pos_ftrace_mod_end = 0;
 	}
 }
 
+/*
+ * The end position (last + 1) of each additional kallsyms section is recorded
+ * in iter->pos_..._end as each section is added, and so can be used to
+ * determine which get_ksymbol_...() function to call next.
+ */
 static int update_iter_mod(struct kallsym_iter *iter, loff_t pos)
 {
 	iter->pos = pos;
 
-	if (iter->pos_ftrace_mod_end > 0 &&
-	    iter->pos_ftrace_mod_end < iter->pos)
-		return get_ksymbol_bpf(iter);
+	if ((!iter->pos_arch_end || iter->pos_arch_end > pos) &&
+	    get_ksymbol_arch(iter))
+		return 1;
 
-	if (iter->pos_mod_end > 0 &&
-	    iter->pos_mod_end < iter->pos) {
-		if (!get_ksymbol_ftrace_mod(iter))
-			return get_ksymbol_bpf(iter);
+	if ((!iter->pos_mod_end || iter->pos_mod_end > pos) &&
+	    get_ksymbol_mod(iter))
 		return 1;
-	}
 
-	if (!get_ksymbol_mod(iter)) {
-		if (!get_ksymbol_ftrace_mod(iter))
-			return get_ksymbol_bpf(iter);
-	}
+	if ((!iter->pos_ftrace_mod_end || iter->pos_ftrace_mod_end > pos) &&
+	    get_ksymbol_ftrace_mod(iter))
+		return 1;
 
-	return 1;
+	return get_ksymbol_bpf(iter);
 }
 
 /* Returns false if pos at or past end of file. */