[makedumpfile][PATCH] handle x86_64 xen code/data relocation
Ken'ichi Ohmichi
oomichi at mxs.nes.nec.co.jp
Mon Jul 7 04:23:34 EDT 2008
Hi ODA-san,
I tested your patch on RHEL5.2 (based on xen-3.1.2).
If both your patch and Takebe-san's patch ([1]) are applied to makedumpfile,
it can work fine. Thank you so much.
I will merge them into the next release.
Thanks
Ken'ichi Ohmichi
[1]: [RFC] makedumpfile: fix for xen-3.1.2
http://lists.infradead.org/pipermail/kexec/2008-April/001533.html
Itsuro ODA wrote:
> Hi all,
>
> Recent version of xen (ex. RHEL5.2, 3.2.0) on the x86_64
> moves the physical(machine) address of xen code/data area after
> the system started up. The start address of this is stored in
> 'xen_phys_start'. Thus to get a machine address of a xen text symbol
> from its virtual address, calculate
> "va - __XEN_VIRT_START + xen_phys_start".
>
> makedumpfile command need the value of xen_phys_start.
> They know the virtual address of 'xen_phys_start' symbol but
> no way to extract the value of xen_phys_start.
>
> I posted a patch which adds the xen_phys_start value to the
> CRASHINFO ElfNote section and It was merged the upstream (xen-unstable
> tree).
>
> This patch enables as follows:
> * add --xen_phys_start option for a vmcore which is relocated and does not
> include the xen_phys_start value in the CRASHINFO.
> * extract the xen_phys_start value from the CRASHINFO if the CRASHINFO
> includes the xen_phys_start value.
>
> (note that the crash command includes this function already.)
>
> This patch is for makedumpfile-1.2.6.
>
> Thanks.
> Itsuro Oda
>
> ---
> --- makedumpfile.h.org 2008-06-12 15:25:43.000000000 +0900
> +++ makedumpfile.h 2008-07-03 10:48:07.000000000 +0900
> @@ -467,6 +467,7 @@ do { \
> #define STRLEN_OSRELEASE (65) /* same length as diskdump.h */
>
> #define XEN_ELFNOTE_CRASH_INFO (0x1000001)
> +#define SIZE_XEN_CRASH_INFO_V2 (sizeof(unsigned long) * 10)
>
> /*
> * The value of dependence on machine
> @@ -778,6 +779,9 @@ struct DumpInfo {
> /*
> * for Xen extraction
> */
> + off_t offset_xen_crash_info;
> + unsigned long size_xen_crash_info;
> + unsigned long xen_phys_start;
> unsigned long xen_heap_start; /* start mfn of xen heap area */
> unsigned long xen_heap_end; /* end mfn(+1) of xen heap area */
> unsigned long frame_table_vaddr;
> @@ -1051,11 +1055,14 @@ int get_xen_info_x86();
> #define HYPERVISOR_VIRT_END (0xffff880000000000)
> #define DIRECTMAP_VIRT_START (0xffff830000000000)
> #define DIRECTMAP_VIRT_END (0xffff840000000000)
> +#define XEN_VIRT_START (0xffff828c80000000)
>
> #define is_xen_vaddr(x) \
> ((x) >= HYPERVISOR_VIRT_START && (x) < HYPERVISOR_VIRT_END)
> #define is_direct(x) \
> ((x) >= DIRECTMAP_VIRT_START && (x) < DIRECTMAP_VIRT_END)
> +#define is_xen_text(x) \
> + ((x) >= XEN_VIRT_START && (x) < DIRECTMAP_VIRT_START)
>
> unsigned long long kvtop_xen_x86_64(unsigned long kvaddr);
> #define kvtop_xen(X) kvtop_xen_x86_64(X)
> --- makedumpfile.c.org 2008-06-12 15:01:26.000000000 +0900
> +++ makedumpfile.c 2008-07-03 12:02:44.000000000 +0900
> @@ -2187,6 +2187,8 @@ read_vmcoreinfo_basic_info()
>
> while (fgets(buf, BUFSIZE_FGETS, info->file_vmcoreinfo)) {
> i = strlen(buf);
> + if (!i)
> + break;
> if (buf[i - 1] == '\n')
> buf[i - 1] = '\0';
> if (strncmp(buf, STR_OSRELEASE, strlen(STR_OSRELEASE)) == 0) {
> @@ -2244,6 +2246,8 @@ read_vmcoreinfo_symbol(char *str_symbol)
>
> while (fgets(buf, BUFSIZE_FGETS, info->file_vmcoreinfo)) {
> i = strlen(buf);
> + if (!i)
> + break;
> if (buf[i - 1] == '\n')
> buf[i - 1] = '\0';
> if (strncmp(buf, str_symbol, strlen(str_symbol)) == 0) {
> @@ -2275,6 +2279,8 @@ read_vmcoreinfo_long(char *str_structure
>
> while (fgets(buf, BUFSIZE_FGETS, info->file_vmcoreinfo)) {
> i = strlen(buf);
> + if (!i)
> + break;
> if (buf[i - 1] == '\n')
> buf[i - 1] = '\0';
> if (strncmp(buf, str_structure, strlen(str_structure)) == 0) {
> @@ -2304,6 +2310,8 @@ read_vmcoreinfo_string(char *str_in, cha
>
> while (fgets(buf, BUFSIZE_FGETS, info->file_vmcoreinfo)) {
> i = strlen(buf);
> + if (!i)
> + break;
> if (buf[i - 1] == '\n')
> buf[i - 1] = '\0';
> if (strncmp(buf, str_in, strlen(str_in)) == 0) {
> @@ -2467,8 +2475,20 @@ get_pt_note_info(off_t off_note, unsigne
> /*
> * Check whether /proc/vmcore contains xen's note.
> */
> - } else if (n_type == XEN_ELFNOTE_CRASH_INFO)
> + } else if (n_type == XEN_ELFNOTE_CRASH_INFO) {
> vt.mem_flags |= MEMORY_XEN;
> + if (info->flag_elf64) {
> + info->offset_xen_crash_info = offset
> + + (sizeof(note64)
> + + ((note64.n_namesz + 3) & ~3));
> + info->size_xen_crash_info = note64.n_descsz;
> + } else {
> + info->offset_xen_crash_info = offset
> + + (sizeof(note32)
> + + ((note32.n_namesz + 3) & ~3));
> + info->size_xen_crash_info = note32.n_descsz;
> + }
> + }
>
> if (info->flag_elf64) {
> offset += sizeof(Elf64_Nhdr)
> @@ -5547,6 +5567,36 @@ get_structure_info_xen()
> }
>
> int
> +get_xen_phys_start(void)
> +{
> + off_t offset;
> + unsigned long xen_phys_start;
> + const off_t failed = (off_t)-1;
> +
> + if (info->xen_phys_start)
> + return TRUE;
> +
> + if (info->size_xen_crash_info >= SIZE_XEN_CRASH_INFO_V2) {
> + offset = info->offset_xen_crash_info + 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;
> + }
> +
> + return TRUE;
> +}
> +
> +int
> get_xen_info()
> {
> unsigned long domain;
> @@ -5706,6 +5756,7 @@ show_data_xen()
> MSG("OFFSET(domain.next_in_list): %ld\n", OFFSET(domain.next_in_list));
>
> MSG("\n");
> + MSG("xen_phys_start: %lx\n", info->xen_phys_start);
> MSG("frame_table_vaddr: %lx\n", info->frame_table_vaddr);
> MSG("xen_heap_start: %lx\n", info->xen_heap_start);
> MSG("xen_heap_end:%lx\n", info->xen_heap_end);
> @@ -5790,6 +5841,8 @@ read_vmcoreinfo_basic_info_xen()
>
> while (fgets(buf, BUFSIZE_FGETS, info->file_vmcoreinfo)) {
> i = strlen(buf);
> + if (!i)
> + break;
> if (buf[i - 1] == '\n')
> buf[i - 1] = '\0';
> if (strncmp(buf, STR_PAGESIZE, strlen(STR_PAGESIZE)) == 0) {
> @@ -6023,6 +6076,8 @@ initial_xen()
> return FALSE;
> unlink(info->name_vmcoreinfo);
> }
> + if (!get_xen_phys_start())
> + return FALSE;
> if (!get_xen_info())
> return FALSE;
>
> @@ -6204,6 +6259,7 @@ check_param_for_creating_dumpfile(int ar
> static struct option longopts[] = {
> {"xen-syms", required_argument, NULL, 'y'},
> {"xen-vmcoreinfo", required_argument, NULL, 'z'},
> + {"xen_phys_start", required_argument, NULL, 'P'},
> {"message-level", required_argument, NULL, 'm'},
> {"help", no_argument, NULL, 'h'},
> {0, 0, 0, 0}
> @@ -6266,6 +6322,9 @@ main(int argc, char *argv[])
> case 'm':
> message_level = atoi(optarg);
> break;
> + case 'P':
> + info->xen_phys_start = strtoul(optarg, NULL, 0);
> + break;
> case 'R':
> info->flag_rearrange = 1;
> break;
> --- x86_64.c.org 2008-06-12 15:16:48.000000000 +0900
> +++ x86_64.c 2008-07-03 10:58:24.000000000 +0900
> @@ -190,6 +190,9 @@ kvtop_xen_x86_64(unsigned long kvaddr)
> if (!is_xen_vaddr(kvaddr))
> return NOT_PADDR;
>
> + if (is_xen_text(kvaddr))
> + return (unsigned long)kvaddr - XEN_VIRT_START + info->xen_phys_start;
> +
> if (is_direct(kvaddr))
> return (unsigned long)kvaddr - DIRECTMAP_VIRT_START;
More information about the kexec
mailing list