OpenE2K
/
dwarves
2
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity

btf_encoder: Factor filter_functions function 

Reorder the filter_functions function so we can add processing of kernel
modules in following patch.

There's no functional change intended.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Hao Luo <haoluo@google.com>
Cc: Yonghong Song <yhs@fb.com>
Cc: bpf@vger.kernel.org
Cc: dwarves@vger.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This commit is contained in:
Jiri Olsa 2020-12-03 23:06:23 +01:00 committed by Arnaldo Carvalho de Melo
parent 1e6a3fed6e
commit aff60970d1
1 changed files with 41 additions and 20 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

61
btf_encoder.c
View File

@ -101,14 +101,21 @@ static int addrs_cmp(const void *_a, const void *_b)
return *a < *b ? -1 : 1;
}
static int filter_functions(struct btf_elf *btfe, struct funcs_layout *fl)
static int get_vmlinux_addrs(struct btf_elf *btfe, struct funcs_layout *fl,
unsigned long **paddrs, unsigned long *pcount)
{
unsigned long *addrs, count, offset, i;
int functions_valid = 0;
unsigned long *addrs, count, offset;
Elf_Data *data;
GElf_Shdr shdr;
Elf_Scn *sec;
/* Initialize for the sake of all error paths below. */
*paddrs = NULL;
*pcount = 0;
if (!fl->mcount_start || !fl->mcount_stop)
return 0;
/*
* Find mcount addressed marked by __start_mcount_loc
* and __stop_mcount_loc symbols and load them into
@ -138,7 +145,32 @@ static int filter_functions(struct btf_elf *btfe, struct funcs_layout *fl)
}
memcpy(addrs, data->d_buf + offset, count * sizeof(addrs[0]));
*paddrs = addrs;
*pcount = count;
return 0;
}
static int setup_functions(struct btf_elf *btfe, struct funcs_layout *fl)
{
unsigned long *addrs, count, i;
int functions_valid = 0;
/*
* Check if we are processing vmlinux image and
* get mcount data if it's detected.
*/
if (get_vmlinux_addrs(btfe, fl, &addrs, &count))
return -1;
if (!addrs) {
if (btf_elf__verbose)
printf("ftrace symbols not detected, falling back to DWARF data\n");
delete_functions();
return 0;
}
qsort(addrs, count, sizeof(addrs[0]), addrs_cmp);
qsort(functions, functions_cnt, sizeof(functions[0]), functions_cmp);
/*
* Let's got through all collected functions and filter
@ -162,6 +194,9 @@ static int filter_functions(struct btf_elf *btfe, struct funcs_layout *fl)
functions_cnt = functions_valid;
free(addrs);
if (btf_elf__verbose)
printf("Found %d functions!\n", functions_cnt);
return 0;
}
@ -470,11 +505,6 @@ static void collect_symbol(GElf_Sym *sym, struct funcs_layout *fl)
fl->mcount_stop = sym->st_value;
}
static int has_all_symbols(struct funcs_layout *fl)
{
return fl->mcount_start && fl->mcount_stop;
}
static int collect_symbols(struct btf_elf *btfe, bool collect_percpu_vars)
{
struct funcs_layout fl = { };
@ -501,18 +531,9 @@ static int collect_symbols(struct btf_elf *btfe, bool collect_percpu_vars)
printf("Found %d per-CPU variables!\n", percpu_var_cnt);
}
if (functions_cnt && has_all_symbols(&fl)) {
qsort(functions, functions_cnt, sizeof(functions[0]), functions_cmp);
if (filter_functions(btfe, &fl)) {
fprintf(stderr, "Failed to filter dwarf functions\n");
return -1;
}
if (btf_elf__verbose)
printf("Found %d functions!\n", functions_cnt);
} else {
if (btf_elf__verbose)
printf("ftrace symbols not detected, falling back to DWARF data\n");
delete_functions();
if (functions_cnt && setup_functions(btfe, &fl)) {
fprintf(stderr, "Failed to filter DWARF functions\n");
return -1;
}
return 0;