[PATCH 02/10] perf symbols: Factor out get_plt_sizes()

From: Adrian Hunter
Date: Fri Jan 20 2023 - 07:35:28 EST


Factor out get_plt_sizes() to make the code more readable and further
changes to dso__synthesize_plt_symbols() easier to follow.

Signed-off-by: Adrian Hunter <adrian.hunter@xxxxxxxxx>
---
tools/perf/util/symbol-elf.c | 54 +++++++++++++++++++-----------------
1 file changed, 28 insertions(+), 26 deletions(-)

diff --git a/tools/perf/util/symbol-elf.c b/tools/perf/util/symbol-elf.c
index 96767d1b3f1c..4605680a22a3 100644
--- a/tools/perf/util/symbol-elf.c
+++ b/tools/perf/util/symbol-elf.c
@@ -323,6 +323,33 @@ static char *demangle_sym(struct dso *dso, int kmodule, const char *elf_name)
return demangled;
}

+static void get_plt_sizes(GElf_Ehdr *ehdr, GElf_Shdr *shdr_plt,
+ u64 *plt_header_size, u64 *plt_entry_size)
+{
+ switch (ehdr->e_machine) {
+ case EM_ARM:
+ *plt_header_size = 20;
+ *plt_entry_size = 12;
+ return;
+ case EM_AARCH64:
+ *plt_header_size = 32;
+ *plt_entry_size = 16;
+ return;
+ case EM_SPARC:
+ *plt_header_size = 48;
+ *plt_entry_size = 12;
+ return;
+ case EM_SPARCV9:
+ *plt_header_size = 128;
+ *plt_entry_size = 32;
+ return;
+ default: /* FIXME: s390/alpha/mips/parisc/poperpc/sh/xtensa need to be checked */
+ *plt_header_size = shdr_plt->sh_entsize;
+ *plt_entry_size = shdr_plt->sh_entsize;
+ return;
+ }
+}
+
#define elf_section__for_each_rel(reldata, pos, pos_mem, idx, nr_entries) \
for (idx = 0, pos = gelf_getrel(reldata, 0, &pos_mem); \
idx < nr_entries; \
@@ -411,32 +438,7 @@ int dso__synthesize_plt_symbols(struct dso *dso, struct symsrc *ss)

nr_rel_entries = shdr_rel_plt.sh_size / shdr_rel_plt.sh_entsize;
plt_offset = shdr_plt.sh_offset;
- switch (ehdr.e_machine) {
- case EM_ARM:
- plt_header_size = 20;
- plt_entry_size = 12;
- break;
-
- case EM_AARCH64:
- plt_header_size = 32;
- plt_entry_size = 16;
- break;
-
- case EM_SPARC:
- plt_header_size = 48;
- plt_entry_size = 12;
- break;
-
- case EM_SPARCV9:
- plt_header_size = 128;
- plt_entry_size = 32;
- break;
-
- default: /* FIXME: s390/alpha/mips/parisc/poperpc/sh/xtensa need to be checked */
- plt_header_size = shdr_plt.sh_entsize;
- plt_entry_size = shdr_plt.sh_entsize;
- break;
- }
+ get_plt_sizes(&ehdr, &shdr_plt, &plt_header_size, &plt_entry_size);
plt_offset += plt_header_size;

if (shdr_rel_plt.sh_type == SHT_RELA) {
--
2.34.1