From: Andrii Nakryiko <andrii@kernel.org>
To: <dwarves@vger.kernel.org>, <acme@kernel.org>, <bpf@vger.kernel.org>
Cc: <andrii@kernel.org>, <kernel-team@fb.com>
Subject: [PATCH dwarves 2/4] libbtf: improve variable naming and error reporting when writing out BTF
Date: Thu, 5 Nov 2020 21:25:47 -0800 [thread overview]
Message-ID: <20201106052549.3782099-3-andrii@kernel.org> (raw)
In-Reply-To: <20201106052549.3782099-1-andrii@kernel.org>
Rename few local variables to reflects the purpose a bit better. Also separate
writing out BTF raw data and objcopy invocation into two separate steps and
improve error reporting for each.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
---
libbtf.c | 33 +++++++++++++++++++++------------
1 file changed, 21 insertions(+), 12 deletions(-)
diff --git a/libbtf.c b/libbtf.c
index babf4fe8cd9e..b6ddd7599395 100644
--- a/libbtf.c
+++ b/libbtf.c
@@ -679,11 +679,11 @@ static int btf_elf__write(const char *filename, struct btf *btf)
{
GElf_Shdr shdr_mem, *shdr;
GElf_Ehdr ehdr_mem, *ehdr;
- Elf_Data *btf_elf = NULL;
+ Elf_Data *btf_data = NULL;
Elf_Scn *scn = NULL;
Elf *elf = NULL;
- const void *btf_data;
- uint32_t btf_size;
+ const void *raw_btf_data;
+ uint32_t raw_btf_size;
int fd, err = -1;
size_t strndx;
@@ -735,18 +735,18 @@ static int btf_elf__write(const char *filename, struct btf *btf)
continue;
char *secname = elf_strptr(elf, strndx, shdr->sh_name);
if (strcmp(secname, ".BTF") == 0) {
- btf_elf = elf_getdata(scn, btf_elf);
+ btf_data = elf_getdata(scn, btf_data);
break;
}
}
- btf_data = btf__get_raw_data(btf, &btf_size);
+ raw_btf_data = btf__get_raw_data(btf, &raw_btf_size);
- if (btf_elf) {
+ if (btf_data) {
/* Exisiting .BTF section found */
- btf_elf->d_buf = (void *)btf_data;
- btf_elf->d_size = btf_size;
- elf_flagdata(btf_elf, ELF_C_SET, ELF_F_DIRTY);
+ btf_data->d_buf = (void *)raw_btf_data;
+ btf_data->d_size = raw_btf_size;
+ elf_flagdata(btf_data, ELF_C_SET, ELF_F_DIRTY);
if (elf_update(elf, ELF_C_NULL) >= 0 &&
elf_update(elf, ELF_C_WRITE) >= 0)
@@ -770,12 +770,21 @@ static int btf_elf__write(const char *filename, struct btf *btf)
goto out;
}
+ if (write(fd, raw_btf_data, raw_btf_size) != raw_btf_size) {
+ fprintf(stderr, "%s: write of %d bytes to '%s' failed: %d!\n",
+ __func__, raw_btf_size, tmp_fn, errno);
+ goto out;
+ }
+
snprintf(cmd, sizeof(cmd), "%s --add-section .BTF=%s %s",
llvm_objcopy, tmp_fn, filename);
+ if (system(cmd)) {
+ fprintf(stderr, "%s: failed to add .BTF section to '%s': %d!\n",
+ __func__, tmp_fn, errno);
+ goto out;
+ }
- if (write(fd, btf_data, btf_size) == btf_size && !system(cmd))
- err = 0;
-
+ err = 0;
unlink(tmp_fn);
}
--
2.24.1
next prev parent reply other threads:[~2020-11-06 5:26 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-11-06 5:25 [PATCH dwarves 0/4] Add split BTF support to pahole Andrii Nakryiko
2020-11-06 5:25 ` [PATCH dwarves 1/4] btf_encoder: fix array index type numbering Andrii Nakryiko
2020-11-06 5:25 ` Andrii Nakryiko [this message]
2020-11-06 5:25 ` [PATCH dwarves 3/4] libbpf: update libbpf submodlue reference to latest master Andrii Nakryiko
2020-11-06 5:25 ` [PATCH dwarves 4/4] btf: add support for split BTF loading and encoding Andrii Nakryiko
2020-11-11 11:56 ` Arnaldo Carvalho de Melo
2020-11-11 12:19 ` Arnaldo Carvalho de Melo
2020-11-11 18:29 ` Andrii Nakryiko
2020-11-11 18:32 ` Arnaldo
2020-11-13 11:35 ` Arnaldo Carvalho de Melo
2020-11-11 18:27 ` Andrii Nakryiko
2020-11-11 18:34 ` Arnaldo
2020-11-11 18:50 ` Andrii Nakryiko
2020-11-10 23:34 ` [PATCH dwarves 0/4] Add split BTF support to pahole Andrii Nakryiko
2020-11-11 0:29 ` Arnaldo
2020-11-11 0:35 ` Andrii Nakryiko
2020-11-11 0:38 ` Arnaldo
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