[PATCH v6 5/8] Prepare the dump loads for kcore analysis.

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@redhat.com>

1 files changed, 142 insertions, 0 deletions

diff --git a/elf_info.c b/elf_info.c
index 25b4baf..5be1990 100644
--- a/elf_info.c
+++ b/elf_info.c
@@ -777,6 +777,148 @@ 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(void)
+{
+	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++;
+	}
+
+	if (!loads) {
+		ERRMSG("Can't get the correct number of PT_LOAD. %s\n",
+		    strerror(errno));
+		return FALSE;
+	}
+
+	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.