Commit-ID: 22916fdb9c50e8fb303bdcedca88fd8798a85844 Gitweb: https://git.kernel.org/tip/22916fdb9c50e8fb303bdcedca88fd8798a85844 Author: Adrian Hunter <adrian.hun...@intel.com> AuthorDate: Tue, 22 May 2018 13:54:45 +0300 Committer: Arnaldo Carvalho de Melo <a...@redhat.com> CommitDate: Wed, 23 May 2018 10:26:44 -0300
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: Adrian Hunter <adrian.hun...@intel.com> Cc: Alexander Shishkin <alexander.shish...@linux.intel.com> Cc: Andi Kleen <a...@linux.intel.com> Cc: Andy Lutomirski <l...@kernel.org> Cc: Dave Hansen <dave.han...@linux.intel.com> Cc: H. Peter Anvin <h...@zytor.com> Cc: Jiri Olsa <jo...@redhat.com> Cc: Joerg Roedel <j...@8bytes.org> Cc: Peter Zijlstra <pet...@infradead.org> Cc: Thomas Gleixner <t...@linutronix.de> Cc: x...@kernel.org Link: http://lkml.kernel.org/r/1526986485-6562-18-git-send-email-adrian.hun...@intel.com Signed-off-by: Arnaldo Carvalho de Melo <a...@redhat.com> --- tools/perf/util/symbol-elf.c | 53 ++++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 51 insertions(+), 2 deletions(-) diff --git a/tools/perf/util/symbol-elf.c b/tools/perf/util/symbol-elf.c index 584966913aeb..29770ea61768 100644 --- a/tools/perf/util/symbol-elf.c +++ b/tools/perf/util/symbol-elf.c @@ -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) { - p->rel = rel; - rel += p->len; + 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; }
