[PATCH V3 16/17] perf buildid-cache: kcore_copy: Copy x86 PTI entry trampoline sections

Adrian Hunter
2018-05-22T10:57:06Z

Identify and copy any sections for x86 PTI entry trampolines.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
---
tools/perf/util/symbol-elf.c | 42 ++++++++++++++++++++++++++++++++++++++++++
1 file changed, 42 insertions(+)

diff --git a/tools/perf/util/symbol-elf.c b/tools/perf/util/symbol-elf.c
index 37d9324c277c..584966913aeb 100644
--- a/tools/perf/util/symbol-elf.c
+++ b/tools/perf/util/symbol-elf.c
@@ -1392,6 +1392,11 @@ struct phdr_data {
struct list_head node;
};

+struct sym_data {
+ u64 addr;
+ struct list_head node;
+};
+
struct kcore_copy_info {
u64 stext;
u64 etext;
@@ -1401,6 +1406,7 @@ struct kcore_copy_info {
u64 last_module_symbol;
size_t phnum;
struct list_head phdrs;
+ struct list_head syms;
};

#define kcore_copy__for_each_phdr(k, p) \
@@ -1441,6 +1447,29 @@ static void kcore_copy__free_phdrs(struct kcore_copy_info *kci)
}
}

+static struct sym_data *kcore_copy__new_sym(struct kcore_copy_info *kci,
+ u64 addr)
+{
+ struct sym_data *s = zalloc(sizeof(*s));
+
+ if (s) {
+ s->addr = addr;
+ list_add_tail(&s->node, &kci->syms);
+ }
+
+ return s;
+}
+
+static void kcore_copy__free_syms(struct kcore_copy_info *kci)
+{
+ struct sym_data *s, *tmp;
+
+ list_for_each_entry_safe(s, tmp, &kci->syms, node) {
+ list_del(&s->node);
+ free(s);
+ }
+}
+
static int kcore_copy__process_kallsyms(void *arg, const char *name, char type,
u64 start)
{
@@ -1471,6 +1500,9 @@ static int kcore_copy__process_kallsyms(void *arg, const char *name, char type,
return 0;
}

+ if (is_entry_trampoline(name) && !kcore_copy__new_sym(kci, start))
+ return -1;
+
return 0;
}

@@ -1538,6 +1570,7 @@ static int kcore_copy__read_map(u64 start, u64 len, u64 pgoff, void *data)
{
struct kcore_copy_info *kci = data;
u64 end = start + len;
+ struct sym_data *sdat;

if (kcore_copy__map(kci, start, end, pgoff, kci->stext, kci->etext))
return -1;
@@ -1546,6 +1579,13 @@ static int kcore_copy__read_map(u64 start, u64 len, u64 pgoff, void *data)
kci->last_module_symbol))
return -1;

+ list_for_each_entry(sdat, &kci->syms, node) {
+ u64 s = round_down(sdat->addr, page_size);
+
+ if (kcore_copy__map(kci, start, end, pgoff, s, s + len))
+ return -1;
+ }
+
return 0;
}

@@ -1740,6 +1780,7 @@ int kcore_copy(const char *from_dir, const char *to_dir)
struct phdr_data *p;

INIT_LIST_HEAD(&kci.phdrs);
+ INIT_LIST_HEAD(&kci.syms);

if (kcore_copy__copy_file(from_dir, to_dir, "kallsyms"))
return -1;
@@ -1806,6 +1847,7 @@ int kcore_copy(const char *from_dir, const char *to_dir)
kcore_copy__unlink(to_dir, "kallsyms");

kcore_copy__free_phdrs(&kci);
+ kcore_copy__free_syms(&kci);

return err;
}
--
1.9.1