Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 22916fdb authored by Adrian Hunter's avatar Adrian Hunter Committed by Arnaldo Carvalho de Melo
Browse files

perf kcore_copy: Amend the offset of sections that remap kernel text 



x86 PTI entry trampolines all map to the same physical page. If that is
reflected in the program headers of /proc/kcore, then do the same for the
copy of kcore.

Signed-off-by: default avatarAdrian 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/1526986485-6562-18-git-send-email-adrian.hunter@intel.com


Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent a1a3a062

tools/perf/util/symbol-elf.c

+51 −2
Original line number Diff line number Diff line
@@ -1390,6 +1390,7 @@ struct phdr_data { 
	u64 addr;

	u64 len;

	struct list_head node;

	struct phdr_data *remaps;

};



struct sym_data {
@@ -1597,16 +1598,62 @@ static int kcore_copy__read_maps(struct kcore_copy_info *kci, Elf *elf) 
	return 0;

}



static void kcore_copy__find_remaps(struct kcore_copy_info *kci)

{

	struct phdr_data *p, *k = NULL;

	u64 kend;



	if (!kci->stext)

		return;



	/* Find phdr that corresponds to the kernel map (contains stext) */

	kcore_copy__for_each_phdr(kci, p) {

		u64 pend = p->addr + p->len - 1;



		if (p->addr <= kci->stext && pend >= kci->stext) {

			k = p;

			break;

		}

	}



	if (!k)

		return;



	kend = k->offset + k->len;



	/* Find phdrs that remap the kernel */

	kcore_copy__for_each_phdr(kci, p) {

		u64 pend = p->offset + p->len;



		if (p == k)

			continue;



		if (p->offset >= k->offset && pend <= kend)

			p->remaps = k;

	}

}



static void kcore_copy__layout(struct kcore_copy_info *kci)

{

	struct phdr_data *p;

	off_t rel = 0;



	kcore_copy__find_remaps(kci);



	kcore_copy__for_each_phdr(kci, p) {

		if (!p->remaps) {

			p->rel = rel;

			rel += p->len;

		}

		kci->phnum += 1;

	}



	kcore_copy__for_each_phdr(kci, p) {

		struct phdr_data *k = p->remaps;



		if (k)

			p->rel = p->offset - k->offset + k->rel;

	}

}



static int kcore_copy__calc_maps(struct kcore_copy_info *kci, const char *dir,
@@ -1821,6 +1868,8 @@ int kcore_copy(const char *from_dir, const char *to_dir) 
	kcore_copy__for_each_phdr(&kci, p) {

		off_t offs = p->rel + offset;



		if (p->remaps)

			continue;

		if (copy_bytes(kcore.fd, p->offset, extract.fd, offs, p->len))

			goto out_extract_close;

	}