[Patch v3 5/7] prepare the dump loads for kcore analysis
Atsushi Kumagai
kumagai-atsushi at mxc.nes.nec.co.jp
Fri Aug 1 00:12:04 PDT 2014
>In kcore, only "System Ram" and "kernel text" program segments
>are needed. And to be more precise, exclude the crashkernel
>memory range.
>
>Signed-off-by: Baoquan He <bhe at redhat.com>
>---
> elf_info.c | 134 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++
> elf_info.h | 1 +
> makedumpfile.h | 1 +
> 3 files changed, 136 insertions(+)
>
>diff --git a/elf_info.c b/elf_info.c
>index edbfc97..6216f51 100644
>--- a/elf_info.c
>+++ b/elf_info.c
>@@ -777,6 +777,140 @@ get_elf_loads(int fd, char *filename)
> return TRUE;
> }
>
>+static int exclude_segment(struct pt_load_segment **pt_loads, unsigned int *num_pt_loads, uint64_t start,
>uint64_t end)
>+{
>+ int i, j, tidx = -1;
>+ unsigned long long vstart, vend, kvstart, kvend;
>+ struct pt_load_segment temp_seg = {0};
>+ kvstart = (ulong)start | PAGE_OFFSET;
>+ kvend = (ulong)end | PAGE_OFFSET;
>+ unsigned long size;
>+
>+ for (i = 0; i < (*num_pt_loads); i++) {
>+ vstart = (*pt_loads)[i].virt_start;
>+ vend = (*pt_loads)[i].virt_end;
>+ if (kvstart < vend && kvend > vstart) {
>+ if (kvstart != vstart && kvend != vend) {
>+ /* Split load segment */
>+ temp_seg.phys_start = end +1;
>+ temp_seg.phys_end = (*pt_loads)[i].phys_end;
>+ temp_seg.virt_start = kvend + 1;
>+ temp_seg.virt_end = vend;
>+ temp_seg.file_offset = (*pt_loads)[i].file_offset + temp_seg.virt_start -
>(*pt_loads)[i].virt_start;
>+
>+ (*pt_loads)[i].virt_end = kvstart - 1;
>+ (*pt_loads)[i].phys_end = start -1;
>+
>+ tidx = i+1;
>+ } else if (kvstart != vstart) {
>+ (*pt_loads)[i].phys_end = start - 1;
>+ (*pt_loads)[i].virt_end = kvstart - 1;
>+ } else {
>+ (*pt_loads)[i].phys_start = end + 1;
>+ (*pt_loads)[i].virt_start = kvend + 1;
>+ }
>+ }
>+ }
>+ /* Insert split load segment, if any. */
>+ if (tidx >= 0) {
>+ size = (*num_pt_loads + 1) * sizeof((*pt_loads)[0]);
>+ (*pt_loads) = realloc((*pt_loads), size);
>+ if (!(*pt_loads) ) {
>+ ERRMSG("Cannot realloc %ld bytes: %s\n",
>+ size + 0UL, strerror(errno));
>+ exit(1);
>+ }
>+ for (j = (*num_pt_loads - 1); j >= tidx; j--)
>+ (*pt_loads)[j+1] = (*pt_loads)[j];
>+ (*pt_loads)[tidx] = temp_seg;
>+ (*num_pt_loads)++;
>+ }
>+ return 0;
>+}
>+
>+static int
>+process_dump_load(struct pt_load_segment *pls)
>+{
>+ unsigned long long paddr;
>+
>+ paddr = vaddr_to_paddr(pls->virt_start);
>+ pls->phys_start = paddr;
>+ pls->phys_end = paddr + (pls->virt_end - pls->virt_start);
>+ DEBUG_MSG("process_dump_load\n");
>+ DEBUG_MSG(" phys_start : %llx\n", pls->phys_start);
>+ DEBUG_MSG(" phys_end : %llx\n", pls->phys_end);
>+ DEBUG_MSG(" virt_start : %llx\n", pls->virt_start);
>+ DEBUG_MSG(" virt_end : %llx\n", pls->virt_end);
>+
>+ return TRUE;
>+}
>+
>+int get_kcore_dump_loads()
>+{
>+ struct pt_load_segment *pls;
>+ int i, j, loads=0;
>+
>+ for (i = 0; i < num_pt_loads; ++i) {
>+ struct pt_load_segment *p = &pt_loads[i];
>+ if (is_vmalloc_addr(p->virt_start))
>+ continue;
>+ loads++;
>+ }
>+
>+ pls = calloc(sizeof(struct pt_load_segment), loads);
>+ if (pls == NULL) {
>+ ERRMSG("Can't allocate memory for the PT_LOAD. %s\n",
>+ strerror(errno));
>+ return FALSE;
>+ }
>+
>+ for (i = 0, j=0; i < num_pt_loads; ++i) {
>+ struct pt_load_segment *p = &pt_loads[i];
>+ if (is_vmalloc_addr(p->virt_start))
>+ continue;
>+ if (j >= loads)
>+ return FALSE;
>+
>+ if (j == 0) {
>+ offset_pt_load_memory = p->file_offset;
>+ if (offset_pt_load_memory == 0) {
>+ ERRMSG("Can't get the offset of page data.\n");
>+ return FALSE;
>+ }
>+ }
>+
>+ pls[j] = *p;
>+ process_dump_load(&pls[j]);
>+ j++;
>+ }
>+
>+ free(pt_loads);
>+ pt_loads = pls;
>+ num_pt_loads = loads;
>+
>+ for (i=0; i<crash_reserved_mem_nr; i++)
>+ {
>+ exclude_segment(&pt_loads, &num_pt_loads, crash_reserved_mem[i].start, crash_reserved_mem[i].end);
>+ }
>+
>+ max_file_offset = 0;
>+ for (i = 0; i < num_pt_loads; ++i) {
>+ struct pt_load_segment *p = &pt_loads[i];
>+ max_file_offset = MAX(max_file_offset,
>+ p->file_offset + p->phys_end - p->phys_start);
>+ }
>+
>+ for (i = 0; i < num_pt_loads; ++i) {
>+ struct pt_load_segment *p = &pt_loads[i];
>+ DEBUG_MSG("LOAD (%d)\n", i);
>+ DEBUG_MSG(" phys_start : %llx\n", p->phys_start);
>+ DEBUG_MSG(" phys_end : %llx\n", p->phys_end);
>+ DEBUG_MSG(" virt_start : %llx\n", p->virt_start);
>+ DEBUG_MSG(" virt_end : %llx\n", p->virt_end);
>+ }
>+
>+ return TRUE;
>+}
>
> /*
> * Get ELF information about /proc/vmcore.
>diff --git a/elf_info.h b/elf_info.h
>index 3ce0138..ba27fdf 100644
>--- a/elf_info.h
>+++ b/elf_info.h
>@@ -46,6 +46,7 @@ int get_elf_info(int fd, char *filename);
> void free_elf_info(void);
> int get_elf_loads(int fd, char *filename);
> int set_kcore_vmcoreinfo(uint64_t vmcoreinfo_addr, uint64_t vmcoreinfo_len);
>+int get_kcore_dump_loads();
>
> int is_elf64_memory(void);
> int is_xen_memory(void);
>diff --git a/makedumpfile.h b/makedumpfile.h
>index 7ffa1ee..8881c76 100644
>--- a/makedumpfile.h
>+++ b/makedumpfile.h
>@@ -719,6 +719,7 @@ unsigned long long vaddr_to_paddr_x86(unsigned long vaddr);
> #endif /* x86 */
>
> #ifdef __x86_64__
>+int is_vmalloc_addr(ulong vaddr);
> int get_phys_base_x86_64(void);
> int get_machdep_info_x86_64(void);
> int get_versiondep_info_x86_64(void);
It will fail to build due to undefined is_vmalloc_addr() except on
x86_64, let's define it also for the other architectures like below:
#ifdef __x86__
int get_machdep_info_x86(void);
int get_versiondep_info_x86(void);
+int is_vmalloc_addr_x86(ulong vaddr);
unsigned long long vaddr_to_paddr_x86(unsigned long vaddr);
#define get_phys_base() TRUE
#define get_machdep_info() get_machdep_info_x86()
#define get_versiondep_info() get_versiondep_info_x86()
#define vaddr_to_paddr(X) vaddr_to_paddr_x86(X)
+#define is_vmalloc_addr(X) is_vmalloc_addr_x86(X)
#endif /* x86 */
Besides, I think it's better to rename the is_vmalloc_addr() in
arch/x86_64.c to is_vmalloc_addr_x86_64().
Thanks
Atsushi Kumagai
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