Instead of seeking individual fields inside the ELF note, copy the corresponding struct type from the Xen sources, so people can understand why the code does what it does.
This is mainly a cleanup patch to improve maintainability, but it also simplifies reusing the crash note data from other places. Signed-off-by: Petr Tesarik <[email protected]> --- elf_info.c | 45 +++++++++++++++++++++++++++++---------------- elf_info.h | 38 +++++++++++++++++++++++++++++++++++++- makedumpfile.c | 28 ++++++++-------------------- makedumpfile.h | 2 -- 4 files changed, 74 insertions(+), 39 deletions(-) --- a/elf_info.c +++ b/elf_info.c @@ -86,9 +86,8 @@ static unsigned long size_eraseinfo; /* * Xen information: */ -static off_t offset_xen_crash_info; +static void *xen_crash_info; static unsigned long size_xen_crash_info; -static unsigned long xen_p2m_mfn; /* @@ -292,8 +291,7 @@ static int get_pt_note_info(void) { int n_type, size_desc; - unsigned long p2m_mfn; - off_t offset, offset_desc, off_p2m = 0; + off_t offset, offset_desc; char buf[VMCOREINFO_XEN_NOTE_NAME_BYTES]; char note[MAX_SIZE_NHDR]; @@ -346,23 +344,25 @@ get_pt_note_info(void) */ } else if (n_type == XEN_ELFNOTE_CRASH_INFO) { flags_memory |= MEMORY_XEN; - offset_xen_crash_info = offset_desc; size_xen_crash_info = size_desc; + xen_crash_info = malloc(size_desc); + if (!xen_crash_info) { + ERRMSG("Can't allocate note (%d bytes). %s\n", + size_desc, strerror(errno)); + return FALSE; + } - off_p2m = offset + offset_next_note(note) - - sizeof(p2m_mfn); - if (lseek(fd_memory, off_p2m, SEEK_SET) < 0){ + if (lseek(fd_memory, offset_desc, SEEK_SET) < 0) { ERRMSG("Can't seek the dump memory(%s). %s\n", name_memory, strerror(errno)); return FALSE; } - if (read(fd_memory, &p2m_mfn, sizeof(p2m_mfn)) - != sizeof(p2m_mfn)) { + if (read(fd_memory, xen_crash_info, size_desc) + != size_desc) { ERRMSG("Can't read the dump memory(%s). %s\n", name_memory, strerror(errno)); return FALSE; } - xen_p2m_mfn = p2m_mfn; /* * Check whether a source dumpfile contains eraseinfo. @@ -826,13 +826,12 @@ get_vmcoreinfo_xen(off_t *offset, unsign *size = size_vmcoreinfo_xen; } -void -get_xen_crash_info(off_t *offset, unsigned long *size) +void * +get_xen_crash_info(unsigned long *size) { - if (offset) - *offset = offset_xen_crash_info; if (size) *size = size_xen_crash_info; + return xen_crash_info; } int @@ -859,9 +858,23 @@ set_eraseinfo(off_t offset, unsigned lon size_eraseinfo = size; } +#if defined(__ia64__) +#define p2m_mfn dom0_mm_pgd_mfn +#else +#define p2m_mfn dom0_pfn_to_mfn_frame_list_list +#endif + unsigned long get_xen_p2m_mfn(void) { - return xen_p2m_mfn; +#if defined(__x86__) || defined(__x86_64__) || defined(__ia64__) + if (xen_crash_info) { + if (size_xen_crash_info >= sizeof(crash_xen_info_v2_t)) + return ((crash_xen_info_v2_t*)xen_crash_info)->p2m_mfn; + if (size_xen_crash_info >= sizeof(crash_xen_info_t)) + return ((crash_xen_info_t*)xen_crash_info)->p2m_mfn; + } +#endif + return 0; } --- a/elf_info.h +++ b/elf_info.h @@ -24,6 +24,42 @@ #define MAX_SIZE_NHDR MAX(sizeof(Elf64_Nhdr), sizeof(Elf32_Nhdr)) +typedef struct { + unsigned long xen_major_version; + unsigned long xen_minor_version; + unsigned long xen_extra_version; + unsigned long xen_changeset; + unsigned long xen_compiler; + unsigned long xen_compile_date; + unsigned long xen_compile_time; + unsigned long tainted; +} crash_xen_info_common_t; + +typedef struct { + crash_xen_info_common_t c; +#if defined(__x86__) || defined(__x86_64__) + /* added by changeset 2b43fb3afb3e: */ + unsigned long dom0_pfn_to_mfn_frame_list_list; +#endif +#if defined(__ia64__) + /* added by changeset d7c3b12014b3: */ + unsigned long dom0_mm_pgd_mfn; +#endif +} crash_xen_info_t; + +/* changeset 439a3e9459f2 added xen_phys_start + * to the middle of the struct... */ +typedef struct { + crash_xen_info_common_t c; +#if defined(__x86__) || defined(__x86_64__) + unsigned long xen_phys_start; + unsigned long dom0_pfn_to_mfn_frame_list_list; +#endif +#if defined(__ia64__) + unsigned long dom0_mm_pgd_mfn; +#endif +} crash_xen_info_v2_t; + off_t paddr_to_offset(unsigned long long paddr); off_t paddr_to_offset2(unsigned long long paddr, off_t hint); @@ -62,7 +98,7 @@ void get_vmcoreinfo(off_t *offset, unsig int has_vmcoreinfo_xen(void); void get_vmcoreinfo_xen(off_t *offset, unsigned long *size); -void get_xen_crash_info(off_t *offset, unsigned long *size); +void *get_xen_crash_info(unsigned long *size); int has_eraseinfo(void); void get_eraseinfo(off_t *offset, unsigned long *size); --- a/makedumpfile.c +++ b/makedumpfile.c @@ -5315,30 +5315,18 @@ get_structure_info_xen(void) int get_xen_phys_start(void) { - off_t offset, offset_xen_crash_info; - unsigned long xen_phys_start, size_xen_crash_info; - const off_t failed = (off_t)-1; + unsigned long size_xen_crash_info; + crash_xen_info_v2_t *xen_crash_info; if (info->xen_phys_start) return TRUE; - get_xen_crash_info(&offset_xen_crash_info, &size_xen_crash_info); - if (size_xen_crash_info >= SIZE_XEN_CRASH_INFO_V2) { - offset = offset_xen_crash_info + size_xen_crash_info - - sizeof(unsigned long) * 2; - if (lseek(info->fd_memory, offset, SEEK_SET) == failed) { - ERRMSG("Can't seek the dump memory(%s). %s\n", - info->name_memory, strerror(errno)); - return FALSE; - } - if (read(info->fd_memory, &xen_phys_start, sizeof(unsigned long)) - != sizeof(unsigned long)) { - ERRMSG("Can't read the dump memory(%s). %s\n", - info->name_memory, strerror(errno)); - return FALSE; - } - info->xen_phys_start = xen_phys_start; - } +#if defined(__x86__) || defined(__x86_64__) + xen_crash_info = get_xen_crash_info(&size_xen_crash_info); + if (xen_crash_info && + size_xen_crash_info >= sizeof(crash_xen_info_v2_t)) + info->xen_phys_start = xen_crash_info->xen_phys_start; +#endif return TRUE; } --- a/makedumpfile.h +++ b/makedumpfile.h @@ -416,8 +416,6 @@ do { \ #define SIZE_BUF_STDIN (4096) #define STRLEN_OSRELEASE (65) /* same length as diskdump.h */ -#define SIZE_XEN_CRASH_INFO_V2 (sizeof(unsigned long) * 10) - /* * The value of dependence on machine */ _______________________________________________ kexec mailing list [email protected] http://lists.infradead.org/mailman/listinfo/kexec
