[Patch v3 3/7] preparation functions for parsing vmcoreinfo

[Atsushi Kumagai]

>Add 2 preparation functions get_elf_loads and get_page_offset, later
>they will be needed for parsing vmcoreinfo.
>
>Meanwhile since get_kernel_version need be called to get page_offset
>before initial() in mem_usage code flow, and surely it will be called
>inside initial() again. Add a static variable to avoid this duplicate
>calling.
>
>Signed-off-by: Baoquan He <bhe at redhat.com>
>---
> elf_info.c     | 50 ++++++++++++++++++++++++++++++++++++++++++++++++++
> elf_info.h     |  1 +
> makedumpfile.c | 23 +++++++++++++++++++++++
> 3 files changed, 74 insertions(+)
>
>diff --git a/elf_info.c b/elf_info.c
>index b277f69..69d3fdb 100644
>--- a/elf_info.c
>+++ b/elf_info.c
>@@ -681,6 +681,56 @@ get_elf32_ehdr(int fd, char *filename, Elf32_Ehdr *ehdr)
> 	return TRUE;
> }
>
>+int
>+get_elf_loads(int fd, char *filename)
>+{
>+	int i, j, phnum, elf_format;
>+	Elf64_Phdr phdr;
>+
>+	/*
>+	 * Check ELF64 or ELF32.
>+	 */
>+	elf_format = check_elf_format(fd, filename, &phnum, &num_pt_loads);
>+	if (elf_format == ELF64)
>+		flags_memory |= MEMORY_ELF64;
>+	else if (elf_format != ELF32)
>+		return FALSE;
>+
>+	if (!num_pt_loads) {
>+		ERRMSG("Can't get the number of PT_LOAD.\n");
>+		return FALSE;
>+	}
>+
>+	/*
>+	 * The below file information will be used as /proc/vmcore.
>+	 */
>+	fd_memory   = fd;
>+	name_memory = filename;
>+
>+	pt_loads = calloc(sizeof(struct pt_load_segment), num_pt_loads);
>+	if (pt_loads == NULL) {
>+		ERRMSG("Can't allocate memory for the PT_LOAD. %s\n",
>+		    strerror(errno));
>+		return FALSE;
>+	}
>+	for (i = 0, j = 0; i < phnum; i++) {
>+		if (!get_phdr_memory(i, &phdr))
>+			return FALSE;
>+
>+		if (phdr.p_type != PT_LOAD)
>+			continue;
>+
>+		if (j >= num_pt_loads)
>+			return FALSE;
>+		if(!dump_Elf_load(&phdr, j))
>+			return FALSE;
>+		j++;
>+	}
>+
>+	return TRUE;
>+}
>+
>+
> /*
>  * Get ELF information about /proc/vmcore.
>  */
>diff --git a/elf_info.h b/elf_info.h
>index 801faff..263d993 100644
>--- a/elf_info.h
>+++ b/elf_info.h
>@@ -44,6 +44,7 @@ int get_elf64_ehdr(int fd, char *filename, Elf64_Ehdr *ehdr);
> int get_elf32_ehdr(int fd, char *filename, Elf32_Ehdr *ehdr);
> int get_elf_info(int fd, char *filename);
> void free_elf_info(void);
>+int get_elf_loads(int fd, char *filename);
>
> int is_elf64_memory(void);
> int is_xen_memory(void);
>diff --git a/makedumpfile.c b/makedumpfile.c
>index 220570e..78aa7a5 100644
>--- a/makedumpfile.c
>+++ b/makedumpfile.c
>@@ -681,6 +681,10 @@ get_kernel_version(char *release)
> 	int32_t version;
> 	long maj, min, rel;
> 	char *start, *end;
>+	static int done = 0;
>+
>+	if (done)
>+		return info->kernel_version;

This function just convert the argument as string into
a number, it shouldn't be affected by external factors.

You should use info->kernel_version in the caller side if
you want to avoid duplicate calling of this function, but
I think it's unnecessary since this function is small.

>
> 	/*
> 	 * This method checks that vmlinux and vmcore are same kernel version.
>@@ -706,6 +710,9 @@ get_kernel_version(char *release)
> 		MSG("The kernel version is not supported.\n");
> 		MSG("The created dumpfile may be incomplete.\n");
> 	}
>+
>+	done = 1;
>+
> 	return version;
> }
>
>@@ -9062,6 +9069,22 @@ int is_crashkernel_mem_reserved(void)
>         return !!crash_reserved_mem_nr;
> }
>
>+static int get_page_offset()
>+{
>+#ifdef __x86_64__
>+	struct utsname utsname;
>+	if (uname(&utsname)) {
>+		ERRMSG("Cannot get name and information about current kernel : %s", strerror(errno));
>+		return FALSE;
>+	}
>+
>+	info->kernel_version = get_kernel_version(utsname.release);
>+	get_versiondep_info_x86_64();
>+#endif /* x86_64 */

You should replace get_versiondep_info_x86_64() with get_versiondep_info()
to get rid of #ifdef.
#ifdef is messy, I don't want to use it if possible.


Thanks
Atsushi Kumagai.

>+
>+	return TRUE;
>+}
>+
> static struct option longopts[] = {
> 	{"split", no_argument, NULL, OPT_SPLIT},
> 	{"reassemble", no_argument, NULL, OPT_REASSEMBLE},
>--
>1.8.5.3