Commit 56549978 authored May 09, 2018 by Adrian Hunter Committed by Arnaldo Carvalho de Melo May 15, 2018

perf tools: Use the "_stest" symbol to identify the kernel map when loading kcore



The first symbol is not necessarily in the kernel text.  Instead of
using the first symbol, use the _stest symbol to identify the kernel map
when loading kcore.

This allows for the introduction of symbols to identify the x86_64 PTI
entry trampolines.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: x86@kernel.org
Link: http://lkml.kernel.org/r/1525866228-30321-6-git-send-email-adrian.hunter@intel.com


Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

parent d8fc764d

tools/perf/util/symbol.c

+8 −8

Original line number	Diff line number	Diff line
		@@ -1149,7 +1149,7 @@ static int dso__load_kcore(struct dso dso, struct map map,
		bool is_64_bit;
		int err, fd;
		char kcore_filename[PATH_MAX];
		struct symbol *sym;
		u64 stext;

		if (!kmaps)
		return -EINVAL;
		@@ -1198,15 +1198,15 @@ static int dso__load_kcore(struct dso dso, struct map map,
		old_map = next;
		}

		/* Find the kernel map using the first symbol */
		sym = dso__first_symbol(dso);
		/* Find the kernel map using the '_stext' symbol */
		if (!kallsyms__get_function_start(kallsyms_filename, "_stext", &stext)) {
		list_for_each_entry(new_map, &md.maps, node) {
		if (sym && sym->start >= new_map->start &&
		sym->start < new_map->end) {
		if (stext >= new_map->start && stext < new_map->end) {
		replacement_map = new_map;
		break;
		}
		}
		}

		if (!replacement_map)
		replacement_map = list_entry(md.maps.next, struct map, node);