// SPDX-License-Identifier: GPL-2.0
#include <linux/compiler.h>
#include <linux/rbtree.h>
#include <inttypes.h>
#include <string.h>
#include <ctype.h>
#include <stdlib.h>
#include "dso.h"
#include "map.h"
#include "symbol.h"
#include <internal/lib.h> // page_size
#include "tests.h"
#include "debug.h"
#include "machine.h"

#define UM(x) map__unmap_ip(kallsyms_map, (x))

static bool is_ignored_symbol(const char *name, char type)
{
        /* Symbol names that exactly match to the following are ignored.*/
        static const char * const ignored_symbols[] = {
                /*
                 * Symbols which vary between passes. Passes 1 and 2 must have
                 * identical symbol lists. The kallsyms_* symbols below are
                 * only added after pass 1, they would be included in pass 2
                 * when --all-symbols is specified so exclude them to get a
                 * stable symbol list.
                 */
                "kallsyms_offsets",
                "kallsyms_num_syms",
                "kallsyms_names",
                "kallsyms_markers",
                "kallsyms_token_table",
                "kallsyms_token_index",
                /* Exclude linker generated symbols which vary between passes */
                "_SDA_BASE_",           /* ppc */
                "_SDA2_BASE_",          /* ppc */
                NULL
        };

        /* Symbol names that begin with the following are ignored.*/
        static const char * const ignored_prefixes[] = {
                "$",                    /* local symbols for ARM, MIPS, etc. */
                ".L",                   /* local labels, .LBB,.Ltmpxxx,.L__unnamed_xx,.LASANPC, etc. */
                "__crc_",               /* modversions */
                "__efistub_",           /* arm64 EFI stub namespace */
                "__kvm_nvhe_$",         /* arm64 local symbols in non-VHE KVM namespace */
                "__kvm_nvhe_.L",        /* arm64 local symbols in non-VHE KVM namespace */
                "__AArch64ADRPThunk_",  /* arm64 lld */
                "__ARMV5PILongThunk_",  /* arm lld */
                "__ARMV7PILongThunk_",
                "__ThumbV7PILongThunk_",
                "__LA25Thunk_",         /* mips lld */
                "__microLA25Thunk_",
                NULL
        };

        /* Symbol names that end with the following are ignored.*/
        static const char * const ignored_suffixes[] = {
                "_from_arm",            /* arm */
                "_from_thumb",          /* arm */
                "_veneer",              /* arm */
                NULL
        };

        /* Symbol names that contain the following are ignored.*/
        static const char * const ignored_matches[] = {
                ".long_branch.",        /* ppc stub */
                ".plt_branch.",         /* ppc stub */
                NULL
        };

        const char * const *p;

        for (p = ignored_symbols; *p; p++)
                if (!strcmp(name, *p))
                        return true;

        for (p = ignored_prefixes; *p; p++)
                if (!strncmp(name, *p, strlen(*p)))
                        return true;

        for (p = ignored_suffixes; *p; p++) {
                int l = strlen(name) - strlen(*p);

                if (l >= 0 && !strcmp(name + l, *p))
                        return true;
        }

        for (p = ignored_matches; *p; p++) {
                if (strstr(name, *p))
                        return true;
        }

        if (type == 'U' || type == 'u')
                return true;
        /* exclude debugging symbols */
        if (type == 'N' || type == 'n')
                return true;

        if (toupper(type) == 'A') {
                /* Keep these useful absolute symbols */
                if (strcmp(name, "__kernel_syscall_via_break") &&
                    strcmp(name, "__kernel_syscall_via_epc") &&
                    strcmp(name, "__kernel_sigtramp") &&
                    strcmp(name, "__gp"))
                        return true;
        }

        return false;
}

struct test__vmlinux_matches_kallsyms_cb_args {
        struct machine kallsyms;
        struct map *vmlinux_map;
        bool header_printed;
};

static int test__vmlinux_matches_kallsyms_cb1(struct map *map, void *data)
{
        struct test__vmlinux_matches_kallsyms_cb_args *args = data;
        struct dso *dso = map__dso(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.
         */
        struct map *pair = maps__find_by_name(args->kallsyms.kmaps,
                                        (dso__kernel(dso) ? dso__short_name(dso) : dso__name(dso)));

        if (pair) {
                map__set_priv(pair);
                map__put(pair);
        } else {
                if (!args->header_printed) {
                        pr_info("WARN: Maps only in vmlinux:\n");
                        args->header_printed = true;
                }
                map__fprintf(map, stderr);
        }
        return 0;
}

static int test__vmlinux_matches_kallsyms_cb2(struct map *map, void *data)
{
        struct test__vmlinux_matches_kallsyms_cb_args *args = data;
        struct map *pair;
        u64 mem_start = map__unmap_ip(args->vmlinux_map, map__start(map));
        u64 mem_end = map__unmap_ip(args->vmlinux_map, map__end(map));

        pair = maps__find(args->kallsyms.kmaps, mem_start);

        if (pair != NULL && !map__priv(pair) && map__start(pair) == mem_start) {
                struct dso *dso = map__dso(map);

                if (!args->header_printed) {
                        pr_info("WARN: Maps in vmlinux with a different name in kallsyms:\n");
                        args->header_printed = true;
                }

                pr_info("WARN: %" PRIx64 "-%" PRIx64 " %" PRIx64 " %s in kallsyms as",
                        map__start(map), map__end(map), map__pgoff(map), dso__name(dso));
                if (mem_end != map__end(pair))
                        pr_info(":\nWARN: *%" PRIx64 "-%" PRIx64 " %" PRIx64,
                                map__start(pair), map__end(pair), map__pgoff(pair));
                pr_info(" %s\n", dso__name(dso));
                map__set_priv(pair);
        }
        map__put(pair);
        return 0;
}

static int test__vmlinux_matches_kallsyms_cb3(struct map *map, void *data)
{
        struct test__vmlinux_matches_kallsyms_cb_args *args = data;

        if (!map__priv(map)) {
                if (!args->header_printed) {
                        pr_info("WARN: Maps only in kallsyms:\n");
                        args->header_printed = true;
                }
                map__fprintf(map, stderr);
        }
        return 0;
}

static int test__vmlinux_matches_kallsyms(struct test_suite *test __maybe_unused,
                                        int subtest __maybe_unused)
{
        int err = TEST_FAIL;
        struct rb_node *nd;
        struct symbol *sym;
        struct map *kallsyms_map;
        struct machine vmlinux;
        struct maps *maps;
        u64 mem_start, mem_end;
        struct test__vmlinux_matches_kallsyms_cb_args args;

        /*
         * 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(&args.kallsyms, "", HOST_KERNEL_ID);
        machine__init(&vmlinux, "", HOST_KERNEL_ID);

        maps = machine__kernel_maps(&vmlinux);

        /*
         * 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(&args.kallsyms) < 0) {
                pr_debug("machine__create_kernel_maps failed");
                err = TEST_SKIP;
                goto out;
        }

        /*
         * Step 3:
         *
         * Load and split /proc/kallsyms into multiple maps, one per module.
         * Do not use kcore, as this test was designed before kcore support
         * and has parts that only make sense if using the non-kcore code.
         * XXX: extend it to stress the kcorre code as well, hint: the list
         * of modules extracted from /proc/kcore, in its current form, can't
         * be compacted against the list of modules found in the "vmlinux"
         * code and with the one got from /proc/modules from the "kallsyms" code.
         */
        if (machine__load_kallsyms(&args.kallsyms, "/proc/kallsyms") <= 0) {
                pr_debug("machine__load_kallsyms failed");
                err = TEST_SKIP;
                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(&args.kallsyms);

        /*
         * Step 5:
         *
         * Now repeat step 2, this time for the vmlinux file we'll auto-locate.
         */
        if (machine__create_kernel_maps(&vmlinux) < 0) {
                pr_info("machine__create_kernel_maps failed");
                goto out;
        }

        args.vmlinux_map = machine__kernel_map(&vmlinux);

        /*
         * 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) <= 0) {
                pr_info("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.
         */
        map__for_each_symbol(args.vmlinux_map, sym, nd) {
                struct symbol *pair, *first_pair;

                sym  = rb_entry(nd, struct symbol, rb_node);

                if (sym->start == sym->end)
                        continue;

                mem_start = map__unmap_ip(args.vmlinux_map, sym->start);
                mem_end = map__unmap_ip(args.vmlinux_map, sym->end);

                first_pair = machine__find_kernel_symbol(&args.kallsyms, mem_start, NULL);
                pair = first_pair;

                if (pair && UM(pair->start) == mem_start) {
next_pair:
                        if (arch__compare_symbol_names(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("WARN: %#" 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 {
                                pair = machine__find_kernel_symbol_by_name(&args.kallsyms,
                                                                           sym->name, NULL);
                                if (pair) {
                                        if (UM(pair->start) == mem_start)
                                                goto next_pair;

                                        pr_debug("WARN: %#" PRIx64 ": diff name v: %s k: %s\n",
                                                 mem_start, sym->name, pair->name);
                                } else {
                                        pr_debug("WARN: %#" PRIx64 ": diff name v: %s k: %s\n",
                                                 mem_start, sym->name, first_pair->name);
                                }

                                continue;
                        }
                } else if (mem_start == map__end(args.kallsyms.vmlinux_map)) {
                        /*
                         * Ignore aliases to _etext, i.e. to the end of the kernel text area,
                         * such as __indirect_thunk_end.
                         */
                        continue;
                } else if (is_ignored_symbol(sym->name, sym->type)) {
                        /*
                         * Ignore hidden symbols, see scripts/kallsyms.c for the details
                         */
                        continue;
                } else {
                        pr_debug("ERR : %#" PRIx64 ": %s not on kallsyms\n",
                                 mem_start, sym->name);
                }

                err = -1;
        }

        if (verbose <= 0)
                goto out;

        args.header_printed = false;
        maps__for_each_map(maps, test__vmlinux_matches_kallsyms_cb1, &args);

        args.header_printed = false;
        maps__for_each_map(maps, test__vmlinux_matches_kallsyms_cb2, &args);

        args.header_printed = false;
        maps = machine__kernel_maps(&args.kallsyms);
        maps__for_each_map(maps, test__vmlinux_matches_kallsyms_cb3, &args);

out:
        machine__exit(&args.kallsyms);
        machine__exit(&vmlinux);
        return err;
}

DEFINE_SUITE("vmlinux symtab matches kallsyms", vmlinux_matches_kallsyms);