在 2019年08月22日 16:51, Simon Horman 写道:
> Hi Lianbo,
>
> I like where this patch is going but I would like to request a few changes.
> Please see comments inline.
>
Thanks for your comment, Simon.
> On Thu, Aug 15, 2019 at 11:37:55AM +0800, Lianbo Jiang wrote:
>> Some code related to vmcore-dmesg.c is put into the util_lib, which
>> is not very reasonable, so lets move it back and tidy up those code.
>>
>> In addition, that will also help to limit the size of vmcore-dmesg.txt.
>>
>> Signed-off-by: Lianbo Jiang <liji...@redhat.com>
>> ---
>> kexec/arch/arm64/kexec-arm64.c | 2 +-
>> util_lib/elf_info.c | 73 ++++++++--------------------------
>> util_lib/include/elf_info.h | 8 +++-
>> vmcore-dmesg/vmcore-dmesg.c | 44 +++++++++++++++++---
>> 4 files changed, 61 insertions(+), 66 deletions(-)
>>
>> diff --git a/kexec/arch/arm64/kexec-arm64.c b/kexec/arch/arm64/kexec-arm64.c
>> index eb3a3a37307c..6ad3b0a134b3 100644
>> --- a/kexec/arch/arm64/kexec-arm64.c
>> +++ b/kexec/arch/arm64/kexec-arm64.c
>> @@ -889,7 +889,7 @@ int get_phys_base_from_pt_load(unsigned long
>> *phys_offset)
>> return EFAILED;
>> }
>>
>> - read_elf_kcore(fd);
>> + read_elf(fd);
>>
>> for (i = 0; get_pt_load(i,
>> &phys_start, NULL, &virt_start, NULL);
>> diff --git a/util_lib/elf_info.c b/util_lib/elf_info.c
>> index 90a3b21662e7..2f254e972721 100644
>> --- a/util_lib/elf_info.c
>> +++ b/util_lib/elf_info.c
>> @@ -20,7 +20,6 @@
>> /* The 32bit and 64bit note headers make it clear we don't care */
>> typedef Elf32_Nhdr Elf_Nhdr;
>>
>> -static const char *fname;
>> static Elf64_Ehdr ehdr;
>> static Elf64_Phdr *phdr;
>> static int num_pt_loads;
>> @@ -120,8 +119,8 @@ void read_elf32(int fd)
>>
>> ret = pread(fd, &ehdr32, sizeof(ehdr32), 0);
>> if (ret != sizeof(ehdr32)) {
>> - fprintf(stderr, "Read of Elf header from %s failed: %s\n",
>> - fname, strerror(errno));
>> + fprintf(stderr, "Read of Elf header failed in %s: %s\n",
>> + __func__, strerror(errno));
>
> I'm not sure of the merit of changing the loging output.
The variable 'fname' is defined two twice, the first definition is in the
vmcore-dmesg.c, and the
second definition is in the elf_info.c. That is confused although it's a static
type, because i do
not see the place where the value of variable 'fname' is set in elf_info.c. So
i guess that it should
be a same variable within the vmcore-dmesg.c and also need to clean up.
> And moreover I don't think it belongs in this patch
> as it doesn't seem related to the other changes.
>
Good question. I will consider how to clean up. Probably, it should be a
separate patch.
>> exit(10);
>> }
>>
>> @@ -193,8 +192,8 @@ void read_elf64(int fd)
>>
>> ret = pread(fd, &ehdr64, sizeof(ehdr64), 0);
>> if (ret < 0 || (size_t)ret != sizeof(ehdr)) {
>> - fprintf(stderr, "Read of Elf header from %s failed: %s\n",
>> - fname, strerror(errno));
>> + fprintf(stderr, "Read of Elf header failed in %s: %s\n",
>> + __func__, strerror(errno));
>> exit(10);
>> }
>>
>> @@ -531,19 +530,7 @@ static int32_t read_file_s32(int fd, uint64_t addr)
>> return read_file_u32(fd, addr);
>> }
>>
>> -static void write_to_stdout(char *buf, unsigned int nr)
>> -{
>> - ssize_t ret;
>> -
>> - ret = write(STDOUT_FILENO, buf, nr);
>> - if (ret != nr) {
>> - fprintf(stderr, "Failed to write out the dmesg log buffer!:"
>> - " %s\n", strerror(errno));
>> - exit(54);
>> - }
>> -}
>> -
>> -static void dump_dmesg_legacy(int fd)
>> +void dump_dmesg_legacy(int fd, handler_t handler)
>> {
>> uint64_t log_buf, log_buf_offset;
>> unsigned log_end, logged_chars, log_end_wrapped;
>> @@ -604,7 +591,7 @@ static void dump_dmesg_legacy(int fd)
>> */
>> logged_chars = log_end < log_buf_len ? log_end : log_buf_len;
>>
>> - write_to_stdout(buf + (log_buf_len - logged_chars), logged_chars);
>> + handler(buf + (log_buf_len - logged_chars), logged_chars);
>> }
>>
>> static inline uint16_t struct_val_u16(char *ptr, unsigned int offset)
>> @@ -623,7 +610,7 @@ static inline uint64_t struct_val_u64(char *ptr,
>> unsigned int offset)
>> }
>>
>> /* Read headers of log records and dump accordingly */
>> -static void dump_dmesg_structured(int fd)
>> +void dump_dmesg_structured(int fd, handler_t handler)
>> {
>> #define OUT_BUF_SIZE 4096
>> uint64_t log_buf, log_buf_offset, ts_nsec;
>> @@ -733,7 +720,7 @@ static void dump_dmesg_structured(int fd)
>> out_buf[len++] = c;
>>
>> if (len >= OUT_BUF_SIZE - 64) {
>> - write_to_stdout(out_buf, len);
>> + handler(out_buf, len);
>> len = 0;
>> }
>> }
>> @@ -753,25 +740,24 @@ static void dump_dmesg_structured(int fd)
>> }
>> free(buf);
>> if (len)
>> - write_to_stdout(out_buf, len);
>> + handler(out_buf, len);
>> }
>>
>> -static void dump_dmesg(int fd)
>> +int check_log_first_idx_vaddr(void)
>> {
>> if (log_first_idx_vaddr)
>> - dump_dmesg_structured(fd);
>> - else
>> - dump_dmesg_legacy(fd);
>> + return 1;
>> +
>> + return 0;
>> }
>>
>> -static int read_elf(int fd)
>> +int read_elf(int fd)
>> {
>> int ret;
>>
>> ret = pread(fd, ehdr.e_ident, EI_NIDENT, 0);
>> if (ret != EI_NIDENT) {
>> - fprintf(stderr, "Read of e_ident from %s failed: %s\n",
>> - fname, strerror(errno));
>> + fprintf(stderr, "Read of e_ident failed: %s\n",
>> strerror(errno));
>> return 3;
>> }
>> if (memcmp(ehdr.e_ident, ELFMAG, SELFMAG) != 0) {
>> @@ -808,40 +794,13 @@ static int read_elf(int fd)
>> return 0;
>> }
>>
>> -int read_elf_vmcore(int fd)
>> -{
>> - int ret;
>> -
>> - ret = read_elf(fd);
>> - if (ret > 0) {
>> - fprintf(stderr, "Unable to read ELF information"
>> - " from vmcore\n");
>> - return ret;
>> - }
>> -
>> - dump_dmesg(fd);
>> -
>> - return 0;
>> -}
>> -
>> -int read_elf_kcore(int fd)
>> -{
>> - int ret;
>> -
>> - ret = read_elf(fd);
>> - if (ret != 0)
>> - return ret;
>> -
>> - return 0;
>> -}
>
> I think that removing read_elf_kcore is not related to the rest of this
> patch and should be in a separate patch - it is a nice cleanup.
>
Good idea, i will split them into a separate patch.
>> -
>> int read_phys_offset_elf_kcore(int fd, unsigned long *phys_off)
>> {
>> int ret;
>>
>> *phys_off = UINT64_MAX;
>>
>> - ret = read_elf_kcore(fd);
>> + ret = read_elf(fd);
>> if (!ret) {
>> /* If we have a valid 'PHYS_OFFSET' by now,
>> * return it to the caller now.
>> diff --git a/util_lib/include/elf_info.h b/util_lib/include/elf_info.h
>> index 1a4debd2d4ba..8ee7d3e2763f 100644
>> --- a/util_lib/include/elf_info.h
>> +++ b/util_lib/include/elf_info.h
>> @@ -23,13 +23,17 @@
>> #include <inttypes.h>
>> #include <ctype.h>
>>
>> +typedef void (*handler_t)(char *msg, unsigned int bytes);
>
> I would prefer it if we did not add new typedefs.
>
OK. I'm considering how to handle it. Any suggestions?
>> +
>> int get_pt_load(int idx,
>> unsigned long long *phys_start,
>> unsigned long long *phys_end,
>> unsigned long long *virt_start,
>> unsigned long long *virt_end);
>> int read_phys_offset_elf_kcore(int fd, unsigned long *phys_off);
>> -int read_elf_kcore(int fd);
>> -int read_elf_vmcore(int fd);
>> +int check_log_first_idx_vaddr(void);
>> +void dump_dmesg_structured(int fd, handler_t handler);
>> +void dump_dmesg_legacy(int fd, handler_t handler);
>> +int read_elf(int fd);
>>
>> #endif /* ELF_INFO_H */
>> diff --git a/vmcore-dmesg/vmcore-dmesg.c b/vmcore-dmesg/vmcore-dmesg.c
>> index 7a386b380291..ff0d540c9130 100644
>> --- a/vmcore-dmesg/vmcore-dmesg.c
>> +++ b/vmcore-dmesg/vmcore-dmesg.c
>> @@ -1,21 +1,53 @@
>> #include <elf_info.h>
>>
>> -/* The 32bit and 64bit note headers make it clear we don't care */
>> -typedef Elf32_Nhdr Elf_Nhdr;
>> +static void write_to_stdout(char *buf, unsigned int nr)
>> +{
>> + ssize_t ret;
>> +
>> + ret = write(STDOUT_FILENO, buf, nr);
>> + if (ret != nr) {
>> + fprintf(stderr, "Failed to write out the dmesg log buffer!:"
>> + " %s\n", strerror(errno));
>> + exit(54);
>> + }
>> +}
>> +
>> +static void dump_dmesg(int fd, handler_t handler)
>> +{
>> + if (check_log_first_idx_vaddr())
>> + dump_dmesg_structured(fd, handler);
>> + else
>> + dump_dmesg_legacy(fd, handler);
>> +}
>
> I think that dump_dmesg() could stay in kexec-arm64.c,
> it does not seem specific to vmcore handling.
>
The dump_dmesg() should be a common function, not only arm64 will use it, but
x86 64 will also call it. It would be good to put the dump_dmesg() to a common
place.
>> -static const char *fname;
>> +static int read_vmcore_dmesg(int fd)
>> +{
>> + int ret;
>> +
>> + ret = read_elf(fd);
>> + if (ret > 0) {
>> + fprintf(stderr, "Unable to read ELF information"
>> + " from vmcore\n");
>> + return ret;
>> + }
>> +
>> + dump_dmesg(fd, write_to_stdout);
>> +
>> + return 0;
>> +}
>>
>> int main(int argc, char **argv)
>> {
>> ssize_t ret;
>> int fd;
>> + const char *fname;
>>
>> if (argc != 2) {
>> fprintf(stderr, "usage: %s <kernel core file>\n", argv[0]);
>> return 1;
>> }
>> - fname = argv[1];
>>
>> + fname = argv[1];
>> fd = open(fname, O_RDONLY);
>> if (fd < 0) {
>> fprintf(stderr, "Cannot open %s: %s\n",
>> @@ -23,8 +55,8 @@ int main(int argc, char **argv)
>> return 2;
>> }
>>
>> - ret = read_elf_vmcore(fd);
>> -
>> + ret = read_vmcore_dmesg(fd);
>> +
>> close(fd);
>>
>> return ret;
>> --
>> 2.17.1
>>
>>
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>> kexec@lists.infradead.org
>> http://lists.infradead.org/mailman/listinfo/kexec
>>
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