Moving find_all_percpu_vars under generic collect_symbols
function that walks over symbols and calls collect_percpu_var.
We will add another collect function that needs to go through
all the symbols, so it's better we go through them just once.
There's no functional change intended.
Acked-by: Hao Luo <haoluo@xxxxxxxxxx>
Signed-off-by: Jiri Olsa <jolsa@xxxxxxxxxx>
---
btf_encoder.c | 124 +++++++++++++++++++++++++++-----------------------
1 file changed, 67 insertions(+), 57 deletions(-)
diff --git a/btf_encoder.c b/btf_encoder.c
index 4c92908beab2..1866bb16a8ba 100644
--- a/btf_encoder.c
+++ b/btf_encoder.c
@@ -250,75 +250,85 @@ static bool percpu_var_exists(uint64_t addr, uint32_t *sz, const char **name)
return true;
}
-static int find_all_percpu_vars(struct btf_elf *btfe)
+static int collect_percpu_var(struct btf_elf *btfe, GElf_Sym *sym)
{
- uint32_t core_id;
- GElf_Sym sym;
+ const char *sym_name;
+ uint64_t addr;
+ uint32_t size;
- /* cache variables' addresses, preparing for searching in symtab. */
- percpu_var_cnt = 0;
+ /* compare a symbol's shndx to determine if it's a percpu variable */
+ if (elf_sym__section(sym) != btfe->percpu_shndx)
+ return 0;
+ if (elf_sym__type(sym) != STT_OBJECT)
+ return 0;
- /* search within symtab for percpu variables */
- elf_symtab__for_each_symbol(btfe->symtab, core_id, sym) {
- const char *sym_name;
- uint64_t addr;
- uint32_t size;
+ addr = elf_sym__value(sym);
+ /*
+ * Store only those symbols that have allocated space in the percpu section.
+ * This excludes the following three types of symbols:
+ *
+ * 1. __ADDRESSABLE(sym), which are forcely emitted as symbols.
+ * 2. __UNIQUE_ID(prefix), which are introduced to generate unique ids.
+ * 3. __exitcall(fn), functions which are labeled as exit calls.
+ *
+ * In addition, the variables defined using DEFINE_PERCPU_FIRST are
+ * also not included, which currently includes:
+ *
+ * 1. fixed_percpu_data
+ */
+ if (!addr)
+ return 0;
- /* compare a symbol's shndx to determine if it's a percpu variable */
- if (elf_sym__section(&sym) != btfe->percpu_shndx)
- continue;
- if (elf_sym__type(&sym) != STT_OBJECT)
- continue;
+ size = elf_sym__size(sym);
+ if (!size)
+ return 0; /* ignore zero-sized symbols */
- addr = elf_sym__value(&sym);
- /*
- * Store only those symbols that have allocated space in the percpu section.
- * This excludes the following three types of symbols:
- *
- * 1. __ADDRESSABLE(sym), which are forcely emitted as symbols.
- * 2. __UNIQUE_ID(prefix), which are introduced to generate unique ids.
- * 3. __exitcall(fn), functions which are labeled as exit calls.
- *
- * In addition, the variables defined using DEFINE_PERCPU_FIRST are
- * also not included, which currently includes:
- *
- * 1. fixed_percpu_data
- */
- if (!addr)
- continue;
+ sym_name = elf_sym__name(sym, btfe->symtab);
+ if (!btf_name_valid(sym_name)) {
+ dump_invalid_symbol("Found symbol of invalid name when encoding btf",
+ sym_name, btf_elf__verbose, btf_elf__force);
+ if (btf_elf__force)
+ return 0;
+ return -1;
+ }
- size = elf_sym__size(&sym);
- if (!size)
- continue; /* ignore zero-sized symbols */
+ if (btf_elf__verbose)
+ printf("Found per-CPU symbol '%s' at address 0x%lx\n", sym_name, addr);
- sym_name = elf_sym__name(&sym, btfe->symtab);
- if (!btf_name_valid(sym_name)) {
- dump_invalid_symbol("Found symbol of invalid name when encoding btf",
- sym_name, btf_elf__verbose, btf_elf__force);
- if (btf_elf__force)
- continue;
- return -1;
- }
+ if (percpu_var_cnt == MAX_PERCPU_VAR_CNT) {
+ fprintf(stderr, "Reached the limit of per-CPU variables: %d\n",
+ MAX_PERCPU_VAR_CNT);
+ return -1;
+ }
+ percpu_vars[percpu_var_cnt].addr = addr;
+ percpu_vars[percpu_var_cnt].sz = size;
+ percpu_vars[percpu_var_cnt].name = sym_name;
+ percpu_var_cnt++;
- if (btf_elf__verbose)
- printf("Found per-CPU symbol '%s' at address 0x%lx\n", sym_name, addr);
+ return 0;
+}
+
+static int collect_symbols(struct btf_elf *btfe, bool collect_percpu_vars)
+{
+ uint32_t core_id;
+ GElf_Sym sym;
- if (percpu_var_cnt == MAX_PERCPU_VAR_CNT) {
- fprintf(stderr, "Reached the limit of per-CPU variables: %d\n",
- MAX_PERCPU_VAR_CNT);
+ /* cache variables' addresses, preparing for searching in symtab. */
+ percpu_var_cnt = 0;
+
+ /* search within symtab for percpu variables */
+ elf_symtab__for_each_symbol(btfe->symtab, core_id, sym) {
+ if (collect_percpu_vars && collect_percpu_var(btfe, &sym))
return -1;
- }
- percpu_vars[percpu_var_cnt].addr = addr;
- percpu_vars[percpu_var_cnt].sz = size;
- percpu_vars[percpu_var_cnt].name = sym_name;
- percpu_var_cnt++;
}
- if (percpu_var_cnt)
- qsort(percpu_vars, percpu_var_cnt, sizeof(percpu_vars[0]), percpu_var_cmp);
+ if (collect_percpu_vars) {
+ if (percpu_var_cnt)
+ qsort(percpu_vars, percpu_var_cnt, sizeof(percpu_vars[0]), percpu_var_cmp);
- if (btf_elf__verbose)
- printf("Found %d per-CPU variables!\n", percpu_var_cnt);
+ if (btf_elf__verbose)
+ printf("Found %d per-CPU variables!\n", percpu_var_cnt);
+ }
return 0;
}
@@ -347,7 +357,7 @@ int cu__encode_btf(struct cu *cu, int verbose, bool force,
if (!btfe)
return -1;
- if (!skip_encoding_vars && find_all_percpu_vars(btfe))
+ if (collect_symbols(btfe, !skip_encoding_vars))
goto out;
has_index_type = false;
--
2.26.2
