From: Jiri Olsa <jolsa@kernel.org>
To: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: dwarves@vger.kernel.org, bpf@vger.kernel.org,
Alexei Starovoitov <ast@kernel.org>,
Andrii Nakryiko <andriin@fb.com>, Yonghong Song <yhs@fb.com>,
Hao Luo <haoluo@google.com>
Subject: [PATCH 1/2] btf_encoder: Factor filter_functions function
Date: Tue, 24 Nov 2020 17:19:18 +0100 [thread overview]
Message-ID: <20201124161919.2152187-2-jolsa@kernel.org> (raw)
In-Reply-To: <20201124161919.2152187-1-jolsa@kernel.org>
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>
---
btf_encoder.c | 57 +++++++++++++++++++++++++++++++++------------------
1 file changed, 37 insertions(+), 20 deletions(-)
diff --git a/btf_encoder.c b/btf_encoder.c
index c40f059580da..467c4657b2c0 100644
--- a/btf_encoder.c
+++ b/btf_encoder.c
@@ -101,14 +101,17 @@ 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;
+ 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 +141,32 @@ 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 = NULL, 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 +190,9 @@ 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 +501,6 @@ 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 +527,9 @@ 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;
--
2.26.2
next prev parent reply other threads:[~2020-11-24 16:19 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-11-24 16:19 [RFC 0/2] btf_encoder: Detect kernel modules Jiri Olsa
2020-11-24 16:19 ` Jiri Olsa [this message]
2020-11-27 4:05 ` [PATCH 1/2] btf_encoder: Factor filter_functions function Andrii Nakryiko
2020-11-27 17:21 ` Jiri Olsa
2020-11-24 16:19 ` [PATCH 2/2] btf_encoder: Detect kernel module ftrace addresses Jiri Olsa
2020-11-27 4:18 ` Andrii Nakryiko
2020-11-27 17:40 ` Jiri Olsa
2020-11-27 20:39 ` Arnaldo Carvalho de Melo
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