[PATCH v2 04/16] scripts/kallsyms: set relative_base more effectively

From: Masahiro Yamada
Date: Sat Nov 23 2019 - 11:05:39 EST


Currently, record_relative_base() iterates over the entire table to
find the minimum address, but it is not efficient because we sort
the table anyway.

After sort_symbol(), the table is sorted by address. (kallsyms parses
the 'nm -n' output, so the data is already sorted by address, but this
commit does not rely on it.)

Move record_relative_base() after sort_symbols(), and take the first
non-absolute symbol value.

Signed-off-by: Masahiro Yamada <yamada.masahiro@xxxxxxxxxxxxx>
---

Changes in v2: None

scripts/kallsyms.c | 12 ++++++++----
1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/scripts/kallsyms.c b/scripts/kallsyms.c
index de986eda41a6..c9efb67c6ecb 100644
--- a/scripts/kallsyms.c
+++ b/scripts/kallsyms.c
@@ -739,11 +739,15 @@ static void record_relative_base(void)
{
unsigned int i;

- relative_base = -1ULL;
for (i = 0; i < table_cnt; i++)
- if (!symbol_absolute(&table[i]) &&
- table[i].addr < relative_base)
+ if (!symbol_absolute(&table[i])) {
+ /*
+ * The table is sorted by address.
+ * Take the first non-absolute symbol value.
+ */
relative_base = table[i].addr;
+ return;
+ }
}

int main(int argc, char **argv)
@@ -767,9 +771,9 @@ int main(int argc, char **argv)
shrink_table();
if (absolute_percpu)
make_percpus_absolute();
+ sort_symbols();
if (base_relative)
record_relative_base();
- sort_symbols();
optimize_token_table();
write_src();

--
2.17.1