| #include <linux/compiler.h> |
| #include <linux/rbtree.h> |
| #include <string.h> |
| #include "map.h" |
| #include "symbol.h" |
| #include "util.h" |
| #include "tests.h" |
| #include "debug.h" |
| #include "machine.h" |
| |
| static int vmlinux_matches_kallsyms_filter(struct map *map __maybe_unused, |
| struct symbol *sym) |
| { |
| bool *visited = symbol__priv(sym); |
| *visited = true; |
| return 0; |
| } |
| |
| #define UM(x) kallsyms_map->unmap_ip(kallsyms_map, (x)) |
| |
| int test__vmlinux_matches_kallsyms(void) |
| { |
| int err = -1; |
| struct rb_node *nd; |
| struct symbol *sym; |
| struct map *kallsyms_map, *vmlinux_map, *map; |
| struct machine kallsyms, vmlinux; |
| enum map_type type = MAP__FUNCTION; |
| struct maps *maps = &vmlinux.kmaps.maps[type]; |
| u64 mem_start, mem_end; |
| |
| /* |
| * Step 1: |
| * |
| * Init the machines that will hold kernel, modules obtained from |
| * both vmlinux + .ko files and from /proc/kallsyms split by modules. |
| */ |
| machine__init(&kallsyms, "", HOST_KERNEL_ID); |
| machine__init(&vmlinux, "", HOST_KERNEL_ID); |
| |
| /* |
| * Step 2: |
| * |
| * Create the kernel maps for kallsyms and the DSO where we will then |
| * load /proc/kallsyms. Also create the modules maps from /proc/modules |
| * and find the .ko files that match them in /lib/modules/`uname -r`/. |
| */ |
| if (machine__create_kernel_maps(&kallsyms) < 0) { |
| pr_debug("machine__create_kernel_maps "); |
| goto out; |
| } |
| |
| /* |
| * Step 3: |
| * |
| * Load and split /proc/kallsyms into multiple maps, one per module. |
| */ |
| if (machine__load_kallsyms(&kallsyms, "/proc/kallsyms", type, NULL) <= 0) { |
| pr_debug("dso__load_kallsyms "); |
| goto out; |
| } |
| |
| /* |
| * Step 4: |
| * |
| * kallsyms will be internally on demand sorted by name so that we can |
| * find the reference relocation * symbol, i.e. the symbol we will use |
| * to see if the running kernel was relocated by checking if it has the |
| * same value in the vmlinux file we load. |
| */ |
| kallsyms_map = machine__kernel_map(&kallsyms, type); |
| |
| /* |
| * Step 5: |
| * |
| * Now repeat step 2, this time for the vmlinux file we'll auto-locate. |
| */ |
| if (machine__create_kernel_maps(&vmlinux) < 0) { |
| pr_debug("machine__create_kernel_maps "); |
| goto out; |
| } |
| |
| vmlinux_map = machine__kernel_map(&vmlinux, type); |
| |
| /* |
| * Step 6: |
| * |
| * Locate a vmlinux file in the vmlinux path that has a buildid that |
| * matches the one of the running kernel. |
| * |
| * While doing that look if we find the ref reloc symbol, if we find it |
| * we'll have its ref_reloc_symbol.unrelocated_addr and then |
| * maps__reloc_vmlinux will notice and set proper ->[un]map_ip routines |
| * to fixup the symbols. |
| */ |
| if (machine__load_vmlinux_path(&vmlinux, type, |
| vmlinux_matches_kallsyms_filter) <= 0) { |
| pr_debug("Couldn't find a vmlinux that matches the kernel running on this machine, skipping test\n"); |
| err = TEST_SKIP; |
| goto out; |
| } |
| |
| err = 0; |
| /* |
| * Step 7: |
| * |
| * Now look at the symbols in the vmlinux DSO and check if we find all of them |
| * in the kallsyms dso. For the ones that are in both, check its names and |
| * end addresses too. |
| */ |
| for (nd = rb_first(&vmlinux_map->dso->symbols[type]); nd; nd = rb_next(nd)) { |
| struct symbol *pair, *first_pair; |
| bool backwards = true; |
| |
| sym = rb_entry(nd, struct symbol, rb_node); |
| |
| if (sym->start == sym->end) |
| continue; |
| |
| mem_start = vmlinux_map->unmap_ip(vmlinux_map, sym->start); |
| mem_end = vmlinux_map->unmap_ip(vmlinux_map, sym->end); |
| |
| first_pair = machine__find_kernel_symbol(&kallsyms, type, |
| mem_start, NULL, NULL); |
| pair = first_pair; |
| |
| if (pair && UM(pair->start) == mem_start) { |
| next_pair: |
| if (strcmp(sym->name, pair->name) == 0) { |
| /* |
| * kallsyms don't have the symbol end, so we |
| * set that by using the next symbol start - 1, |
| * in some cases we get this up to a page |
| * wrong, trace_kmalloc when I was developing |
| * this code was one such example, 2106 bytes |
| * off the real size. More than that and we |
| * _really_ have a problem. |
| */ |
| s64 skew = mem_end - UM(pair->end); |
| if (llabs(skew) >= page_size) |
| pr_debug("%#" PRIx64 ": diff end addr for %s v: %#" PRIx64 " k: %#" PRIx64 "\n", |
| mem_start, sym->name, mem_end, |
| UM(pair->end)); |
| |
| /* |
| * Do not count this as a failure, because we |
| * could really find a case where it's not |
| * possible to get proper function end from |
| * kallsyms. |
| */ |
| continue; |
| |
| } else { |
| struct rb_node *nnd; |
| detour: |
| nnd = backwards ? rb_prev(&pair->rb_node) : |
| rb_next(&pair->rb_node); |
| if (nnd) { |
| struct symbol *next = rb_entry(nnd, struct symbol, rb_node); |
| |
| if (UM(next->start) == mem_start) { |
| pair = next; |
| goto next_pair; |
| } |
| } |
| |
| if (backwards) { |
| backwards = false; |
| pair = first_pair; |
| goto detour; |
| } |
| |
| pr_debug("%#" PRIx64 ": diff name v: %s k: %s\n", |
| mem_start, sym->name, pair->name); |
| } |
| } else |
| pr_debug("%#" PRIx64 ": %s not on kallsyms\n", |
| mem_start, sym->name); |
| |
| err = -1; |
| } |
| |
| if (!verbose) |
| goto out; |
| |
| pr_info("Maps only in vmlinux:\n"); |
| |
| for (map = maps__first(maps); map; map = map__next(map)) { |
| struct map * |
| /* |
| * If it is the kernel, kallsyms is always "[kernel.kallsyms]", while |
| * the kernel will have the path for the vmlinux file being used, |
| * so use the short name, less descriptive but the same ("[kernel]" in |
| * both cases. |
| */ |
| pair = map_groups__find_by_name(&kallsyms.kmaps, type, |
| (map->dso->kernel ? |
| map->dso->short_name : |
| map->dso->name)); |
| if (pair) |
| pair->priv = 1; |
| else |
| map__fprintf(map, stderr); |
| } |
| |
| pr_info("Maps in vmlinux with a different name in kallsyms:\n"); |
| |
| for (map = maps__first(maps); map; map = map__next(map)) { |
| struct map *pair; |
| |
| mem_start = vmlinux_map->unmap_ip(vmlinux_map, map->start); |
| mem_end = vmlinux_map->unmap_ip(vmlinux_map, map->end); |
| |
| pair = map_groups__find(&kallsyms.kmaps, type, mem_start); |
| if (pair == NULL || pair->priv) |
| continue; |
| |
| if (pair->start == mem_start) { |
| pair->priv = 1; |
| pr_info(" %" PRIx64 "-%" PRIx64 " %" PRIx64 " %s in kallsyms as", |
| map->start, map->end, map->pgoff, map->dso->name); |
| if (mem_end != pair->end) |
| pr_info(":\n*%" PRIx64 "-%" PRIx64 " %" PRIx64, |
| pair->start, pair->end, pair->pgoff); |
| pr_info(" %s\n", pair->dso->name); |
| pair->priv = 1; |
| } |
| } |
| |
| pr_info("Maps only in kallsyms:\n"); |
| |
| maps = &kallsyms.kmaps.maps[type]; |
| |
| for (map = maps__first(maps); map; map = map__next(map)) { |
| if (!map->priv) |
| map__fprintf(map, stderr); |
| } |
| out: |
| machine__exit(&kallsyms); |
| machine__exit(&vmlinux); |
| return err; |
| } |