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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.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: Arnaldo Carvalho de Melo <acme@redhat.com>
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a1a3a0624e
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1 changed files with 51 additions and 2 deletions
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@ -1390,6 +1390,7 @@ struct phdr_data {
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u64 addr;
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u64 len;
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struct list_head node;
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struct phdr_data *remaps;
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};
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struct sym_data {
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@ -1597,16 +1598,62 @@ static int kcore_copy__read_maps(struct kcore_copy_info *kci, Elf *elf)
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return 0;
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}
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static void kcore_copy__find_remaps(struct kcore_copy_info *kci)
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{
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struct phdr_data *p, *k = NULL;
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u64 kend;
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if (!kci->stext)
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return;
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/* Find phdr that corresponds to the kernel map (contains stext) */
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kcore_copy__for_each_phdr(kci, p) {
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u64 pend = p->addr + p->len - 1;
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if (p->addr <= kci->stext && pend >= kci->stext) {
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k = p;
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break;
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}
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}
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if (!k)
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return;
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kend = k->offset + k->len;
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/* Find phdrs that remap the kernel */
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kcore_copy__for_each_phdr(kci, p) {
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u64 pend = p->offset + p->len;
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if (p == k)
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continue;
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if (p->offset >= k->offset && pend <= kend)
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p->remaps = k;
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}
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}
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static void kcore_copy__layout(struct kcore_copy_info *kci)
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{
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struct phdr_data *p;
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off_t rel = 0;
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kcore_copy__find_remaps(kci);
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kcore_copy__for_each_phdr(kci, p) {
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p->rel = rel;
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rel += p->len;
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if (!p->remaps) {
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p->rel = rel;
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rel += p->len;
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}
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kci->phnum += 1;
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}
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kcore_copy__for_each_phdr(kci, p) {
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struct phdr_data *k = p->remaps;
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if (k)
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p->rel = p->offset - k->offset + k->rel;
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}
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}
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static int kcore_copy__calc_maps(struct kcore_copy_info *kci, const char *dir,
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@ -1821,6 +1868,8 @@ int kcore_copy(const char *from_dir, const char *to_dir)
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kcore_copy__for_each_phdr(&kci, p) {
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off_t offs = p->rel + offset;
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if (p->remaps)
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continue;
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if (copy_bytes(kcore.fd, p->offset, extract.fd, offs, p->len))
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goto out_extract_close;
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}
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