[makedumpfile][PATCH] handle x86_64 xen code/data relocation
Itsuro ODA
oda at valinux.co.jp
Thu Jul 3 20:27:27 EDT 2008
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;
--
Itsuro ODA <oda at valinux.co.jp>
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