Re: [PATCH v4] kallsyms: add names of built-in modules

Eugene Loh
2019-12-18T23:56:19Z

Ping.

On 12/10/2019 09:48 AM, eugene.loh@oracle.com wrote:
> From: Eugene Loh <eugene.loh@oracle.com>
>
> /proc/kallsyms is very useful for tracers and other tools that need
> to map kernel symbols to addresses.
>
> It would be useful if there were a mapping between kernel symbol and
> module name that only changed when the kernel source code is changed.
> This mapping should not vanish simply because a module becomes built
> into the kernel.
>
> Therefore:
>
> - Generate a file "modules_thick.builtin" that maps from thin
> archives that make up built-in modules to their constituent
> object files.
>
> - Generate a linker map ".tmp_vmlinux.map", converting it into
> ".tmp_vmlinux.ranges", mapping address ranges to object files.
>
> - Read "modules_thick.builtin" and ".tmp_vmlinux.ranges" to
> map symbol addresses to built-in-module names. Write those
> module names (kallsyms_modules) and that per-symbol module
> information (kallsyms_symbol_modules) to the *.s output file.
>
> - Use kallsyms_modules and kallsyms_symbol_modules to add
> built-in-module information to /proc/kallsyms.
>
> Note that kernel symbols for built-in modules appear in ascending
> order by address, as usual, and thus will appear interspersed with
> symbols that are part of other built-in modules or of the kernel.
>
> Also, while it is possible for an object to appear in multiple
> built-in modules, making an unambiguous mapping of symbol to module
> impossible in such cases, this patch addresses the typical cases.
>
> Signed-off-by: Kris Van Hees <kris.van.hees@oracle.com>
> Signed-off-by: Nick Alcock <nick.alcock@oracle.com>
> Signed-off-by: Eugene Loh <eugene.loh@oracle.com>
> Reviewed-by: Kris Van Hees <kris.van.hees@oracle.com>
> ---
> .gitignore | 1 +
> Documentation/dontdiff | 1 +
> Makefile | 41 +++--
> kernel/kallsyms.c | 12 +-
> scripts/Makefile | 5 +
> scripts/Makefile.modbuiltin | 20 ++-
> scripts/kallsyms.c | 298 +++++++++++++++++++++++++++++++++++-
> scripts/link-vmlinux.sh | 17 ++
> scripts/modules_thick.c | 104 +++++++++++++
> scripts/modules_thick.h | 27 ++++
> scripts/namespace.pl | 5 +
> 11 files changed, 509 insertions(+), 22 deletions(-)
> create mode 100644 scripts/modules_thick.c
> create mode 100644 scripts/modules_thick.h
>
> diff --git a/.gitignore b/.gitignore
> index 72ef86a5570d..0b9c88f1d388 100644
> --- a/.gitignore
> +++ b/.gitignore
> @@ -46,6 +46,7 @@
> Module.symvers
> modules.builtin
> modules.order
> +modules_thick.builtin
>
> #
> # Top-level generic files
> diff --git a/Documentation/dontdiff b/Documentation/dontdiff
> index 72fc2e9e2b63..9d0db2ef3a51 100644
> --- a/Documentation/dontdiff
> +++ b/Documentation/dontdiff
> @@ -181,6 +181,7 @@ modules.builtin
> modules.builtin.modinfo
> modules.nsdeps
> modules.order
> +modules_thick.builtin
> modversions.h*
> nconf
> nconf-cfg
> diff --git a/Makefile b/Makefile
> index 73e3c2802927..430d49d3a93e 100644
> --- a/Makefile
> +++ b/Makefile
> @@ -1073,7 +1073,7 @@ cmd_link-vmlinux = \
> $(CONFIG_SHELL) $< $(LD) $(KBUILD_LDFLAGS) $(LDFLAGS_vmlinux) ; \
> $(if $(ARCH_POSTLINK), $(MAKE) -f $(ARCH_POSTLINK) $@, true)
>
> -vmlinux: scripts/link-vmlinux.sh autoksyms_recursive $(vmlinux-deps) FORCE
> +vmlinux: scripts/link-vmlinux.sh autoksyms_recursive $(vmlinux-deps) modules_thick.builtin FORCE
> +$(call if_changed,link-vmlinux)
>
> targets := vmlinux
> @@ -1284,17 +1284,6 @@ modules: $(if $(KBUILD_BUILTIN),vmlinux) modules.order modules.builtin
> modules.order: descend
> $(Q)$(AWK) '!x[$$0]++' $(addsuffix /$@, $(build-dirs)) > $@
>
> -modbuiltin-dirs := $(addprefix _modbuiltin_, $(build-dirs))
> -
> -modules.builtin: $(modbuiltin-dirs)
> - $(Q)$(AWK) '!x[$$0]++' $(addsuffix /$@, $(build-dirs)) > $@
> -
> -PHONY += $(modbuiltin-dirs)
> -# tristate.conf is not included from this Makefile. Add it as a prerequisite
> -# here to make it self-healing in case somebody accidentally removes it.
> -$(modbuiltin-dirs): include/config/tristate.conf
> - $(Q)$(MAKE) $(modbuiltin)=$(patsubst _modbuiltin_%,%,$@)
> -
> # Target to prepare building external modules
> PHONY += modules_prepare
> modules_prepare: prepare
> @@ -1347,6 +1336,33 @@ modules modules_install:
>
> endif # CONFIG_MODULES
>
> +# modules.builtin has a 'thick' form which maps from kernel modules (or rather
> +# the object file names they would have had had they not been built in) to their
> +# constituent object files: kallsyms uses this to determine which modules any
> +# given object file is part of. (We cannot eliminate the slight redundancy
> +# here without double-expansion.)
> +
> +modbuiltin-dirs := $(addprefix _modbuiltin_, $(build-dirs))
> +
> +modbuiltin-thick-dirs := $(addprefix _modbuiltin_thick_, $(build-dirs))
> +
> +modules.builtin: $(modbuiltin-dirs)
> + $(Q)$(AWK) '!x[$$0]++' $(addsuffix /$@, $(build-dirs)) > $@
> +
> +modules_thick.builtin: $(modbuiltin-thick-dirs)
> + $(Q)$(AWK) '!x[$$0]++' $(addsuffix /$@, $(build-dirs)) > $@
> +
> +PHONY += $(modbuiltin-dirs) $(modbuiltin-thick-dirs)
> +# tristate.conf is not included from this Makefile. Add it as a prerequisite
> +# here to make it self-healing in case somebody accidentally removes it.
> +$(modbuiltin-dirs): include/config/tristate.conf
> + $(Q)$(MAKE) $(modbuiltin)=$(patsubst _modbuiltin_%,%,$@) \
> + builtin-file=modules.builtin
> +
> +$(modbuiltin-thick-dirs): include/config/tristate.conf
> + $(Q)$(MAKE) $(modbuiltin)=$(patsubst _modbuiltin_thick_%,%,$@) \
> + builtin-file=modules_thick.builtin
> +
> ###
> # Cleaning is done on three levels.
> # make clean Delete most generated files
> @@ -1712,6 +1728,7 @@ clean: $(clean-dirs)
> -o -name '*.asn1.[ch]' \
> -o -name '*.symtypes' -o -name 'modules.order' \
> -o -name modules.builtin -o -name '.tmp_*.o.*' \
> + -o -name modules_thick.builtin \
> -o -name '*.c.[012]*.*' \
> -o -name '*.ll' \
> -o -name '*.gcno' \) -type f -print | xargs rm -f
> diff --git a/kernel/kallsyms.c b/kernel/kallsyms.c
> index 136ce049c4ad..ce8576503e35 100644
> --- a/kernel/kallsyms.c
> +++ b/kernel/kallsyms.c
> @@ -46,6 +46,8 @@ __attribute__((weak, section(".rodata")));
>
> extern const u8 kallsyms_token_table[] __weak;
> extern const u16 kallsyms_token_index[] __weak;
> +extern const char kallsyms_modules[] __weak;
> +extern const u32 kallsyms_symbol_modules[] __weak;
>
> extern const unsigned int kallsyms_markers[] __weak;
>
> @@ -508,8 +510,16 @@ static int get_ksymbol_bpf(struct kallsym_iter *iter)
> static unsigned long get_ksymbol_core(struct kallsym_iter *iter)
> {
> unsigned off = iter->nameoff;
> + u32 mod_index = 0;
>
> - iter->module_name[0] = '\0';
> + if (kallsyms_symbol_modules)
> + mod_index = kallsyms_symbol_modules[iter->pos];
> +
> + if (mod_index == 0 || kallsyms_modules == NULL)
> + iter->module_name[0] = '\0';
> + else
> + strcpy(iter->module_name, &kallsyms_modules[mod_index]);
> + iter->exported = 0;
> iter->value = kallsyms_sym_address(iter->pos);
>
> iter->type = kallsyms_get_symbol_type(off);
> diff --git a/scripts/Makefile b/scripts/Makefile
> index 00c47901cb06..44641cabb261 100644
> --- a/scripts/Makefile
> +++ b/scripts/Makefile
> @@ -26,6 +26,11 @@ HOSTLDLIBS_extract-cert = -lcrypto
>
> always := $(hostprogs-y) $(hostprogs-m)
>
> +kallsyms-objs := kallsyms.o
> +kallsyms-objs += modules_thick.o
> +
> +HOSTCFLAGS_modules_thick.o := -I$(srctree)/scripts
> +HOSTCFLAGS_kallsyms.o := -I$(srctree)/scripts
> # The following hostprogs-y programs are only build on demand
> hostprogs-y += unifdef
>
> diff --git a/scripts/Makefile.modbuiltin b/scripts/Makefile.modbuiltin
> index 7d4711b88656..06f31e58111e 100644
> --- a/scripts/Makefile.modbuiltin
> +++ b/scripts/Makefile.modbuiltin
> @@ -1,6 +1,6 @@
> # SPDX-License-Identifier: GPL-2.0
> # ==========================================================================
> -# Generating modules.builtin
> +# Generating modules.builtin and modules_thick.builtin
> # ==========================================================================
>
> src := $(obj)
> @@ -30,19 +30,29 @@ __subdir-Y := $(patsubst %/,%,$(filter %/, $(obj-Y)))
> subdir-Y += $(__subdir-Y)
> subdir-ym := $(sort $(subdir-y) $(subdir-Y) $(subdir-m))
> subdir-ym := $(addprefix $(obj)/,$(subdir-ym))
> -obj-Y := $(addprefix $(obj)/,$(obj-Y))
> +pathobj-Y := $(addprefix $(obj)/,$(obj-Y))
>
> modbuiltin-subdirs := $(patsubst %,%/modules.builtin, $(subdir-ym))
> -modbuiltin-mods := $(filter %.ko, $(obj-Y:.o=.ko))
> +modbuiltin-mods := $(filter %.ko, $(pathobj-Y:.o=.ko))
> modbuiltin-target := $(obj)/modules.builtin
> +modthickbuiltin-subdirs := $(patsubst %,%/modules_thick.builtin, $(subdir-ym))
> +modthickbuiltin-target := $(obj)/modules_thick.builtin
>
> -__modbuiltin: $(modbuiltin-target) $(subdir-ym)
> +__modbuiltin: $(obj)/$(builtin-file) $(subdir-ym)
> @:
>
> $(modbuiltin-target): $(subdir-ym) FORCE
> $(Q)(for m in $(modbuiltin-mods); do echo $$m; done; \
> cat /dev/null $(modbuiltin-subdirs)) > $@
>
> +$(modthickbuiltin-target): $(subdir-ym) FORCE
> + $(Q) $(foreach mod-o, $(filter %.o,$(obj-Y)),\
> + printf "%s:" $(addprefix $(obj)/,$(mod-o)) >> $@; \
> + printf " %s" $(sort $(strip $(addprefix $(obj)/,$($(mod-o:.o=-objs)) \
> + $($(mod-o:.o=-y)) $($(mod-o:.o=-Y))))) >> $@; \
> + printf "\n" >> $@; ) \
> + cat /dev/null $(modthickbuiltin-subdirs) >> $@;
> +
> PHONY += FORCE
>
> FORCE:
> @@ -52,6 +62,6 @@ FORCE:
>
> PHONY += $(subdir-ym)
> $(subdir-ym):
> - $(Q)$(MAKE) $(modbuiltin)=$@
> + $(Q)$(MAKE) $(modbuiltin)=$@ builtin-file=$(builtin-file)
>
> .PHONY: $(PHONY)
> diff --git a/scripts/kallsyms.c b/scripts/kallsyms.c
> index fb55f262f42d..7368996e5d7b 100644
> --- a/scripts/kallsyms.c
> +++ b/scripts/kallsyms.c
> @@ -5,7 +5,8 @@
> * This software may be used and distributed according to the terms
> * of the GNU General Public License, incorporated herein by reference.
> *
> - * Usage: nm -n vmlinux | scripts/kallsyms [--all-symbols] > symbols.S
> + * Usage: nm -n vmlinux | scripts/kallsyms [--all-symbols]
> + * [--absolute-percpu] [--base-relative] > symbols.S
> *
> * Table compression uses all the unused char codes on the symbols and
> * maps these to the most used substrings (tokens). For instance, it might
> @@ -18,12 +19,15 @@
> *
> */
>
> +#define _GNU_SOURCE 1
> #include <stdbool.h>
> #include <stdio.h>
> #include <stdlib.h>
> #include <string.h>
> #include <ctype.h>
> #include <limits.h>
> +#include <errno.h>
> +#include "modules_thick.h"
>
> #define ARRAY_SIZE(arr) (sizeof(arr) / sizeof(arr[0]))
>
> @@ -35,6 +39,7 @@ struct sym_entry {
> unsigned int start_pos;
> unsigned char *sym;
> unsigned int percpu_absolute;
> + unsigned int module;
> };
>
> struct addr_range {
> @@ -68,10 +73,101 @@ static unsigned char best_table[256][2];
> static unsigned char best_table_len[256];
>
>
> +static unsigned int strhash(const char *s)
> +{
> + /* fnv32 hash */
> + unsigned int hash = 2166136261U;
> +
> + for (; *s; s++)
> + hash = (hash ^ *s) * 0x01000193;
> + return hash;
> +}
> +
> +#define OBJ2MOD_BITS 10
> +#define OBJ2MOD_N (1 << OBJ2MOD_BITS)
> +#define OBJ2MOD_MASK (OBJ2MOD_N - 1)
> +struct obj2mod_elem {
> + char *obj;
> + int mod;
> + struct obj2mod_elem *next;
> +};
> +
> +static struct obj2mod_elem *obj2mod[OBJ2MOD_N];
> +
> +static void obj2mod_put(const char *obj, int mod)
> +{
> + int i = strhash(obj) & OBJ2MOD_MASK;
> + struct obj2mod_elem *elem = malloc(sizeof(struct obj2mod_elem));
> +
> + if (!elem) {
> + fprintf(stderr, "kallsyms: out of memory\n");
> + exit(1);
> + }
> +
> + elem->obj = strdup(obj);
> + if (!elem->obj) {
> + fprintf(stderr, "kallsyms: out of memory\n");
> + free(elem);
> + exit(1);
> + }
> +
> + elem->mod = mod;
> + elem->next = obj2mod[i];
> + obj2mod[i] = elem;
> +}
> +
> +static int obj2mod_get(const char *obj)
> +{
> + int i = strhash(obj) & OBJ2MOD_MASK;
> + struct obj2mod_elem *elem;
> +
> + for (elem = obj2mod[i]; elem; elem = elem->next)
> + if (strcmp(elem->obj, obj) == 0)
> + return elem->mod;
> + return 0;
> +}
> +
> +static void obj2mod_free(void)
> +{
> + int i;
> +
> + for (i = 0; i < OBJ2MOD_N; i++) {
> + struct obj2mod_elem *elem = obj2mod[i];
> + struct obj2mod_elem *next;
> +
> + while (elem) {
> + next = elem->next;
> + free(elem->obj);
> + free(elem);
> + elem = next;
> + }
> + }
> +}
> +
> +/*
> + * The builtin module names. The "offset" points to the name as if
> + * all builtin module names were concatenated to a single string.
> + */
> +static unsigned int builtin_module_size; /* number allocated */
> +static unsigned int builtin_module_len; /* number assigned */
> +static char **builtin_modules; /* array of module names */
> +static unsigned int *builtin_module_offsets; /* offset */
> +
> +/*
> + * An ordered list of address ranges and how they map to built-in modules.
> + */
> +struct addrmap_entry {
> + unsigned long long addr;
> + unsigned long long size;
> + unsigned int module;
> +};
> +static struct addrmap_entry *addrmap;
> +static int addrmap_num, addrmap_alloced;
> +
> static void usage(void)
> {
> - fprintf(stderr, "Usage: kallsyms [--all-symbols] "
> - "[--base-relative] < in.map > out.S\n");
> + fprintf(stderr, "Usage: kallsyms [--all-symbols] [--absolute-percpu] "
> + "[--base-relative] < nm_vmlinux.out > symbols.S\n");
> exit(1);
> }
>
> @@ -98,6 +194,8 @@ static bool is_ignored_symbol(const char *name, char type)
> "kallsyms_markers",
> "kallsyms_token_table",
> "kallsyms_token_index",
> + "kallsyms_symbol_modules",
> + "kallsyms_modules",
> /* Exclude linker generated symbols which vary between passes */
> "_SDA_BASE_", /* ppc */
> "_SDA2_BASE_", /* ppc */
> @@ -174,10 +272,23 @@ static void check_symbol_range(const char *sym, unsigned long long addr,
> }
> }
>
> +static int addrmap_compare(const void *keyp, const void *rangep)
> +{
> + unsigned long long addr = *((const unsigned long long *)keyp);
> + const struct addrmap_entry *range = rangep;
> +
> + if (addr < range->addr)
> + return -1;
> + if (addr < range->addr + range->size)
> + return 0;
> + return 1;
> +}
> +
> static int read_symbol(FILE *in, struct sym_entry *s)
> {
> char sym[500], stype;
> int rc;
> + struct addrmap_entry *range;
>
> rc = fscanf(in, "%llx %c %499s\n", &s->addr, &stype, sym);
> if (rc != 3) {
> @@ -202,6 +313,14 @@ static int read_symbol(FILE *in, struct sym_entry *s)
> check_symbol_range(sym, s->addr, text_ranges, ARRAY_SIZE(text_ranges));
> check_symbol_range(sym, s->addr, &percpu_range, 1);
>
> + /* try to find a module that this address belongs to */
> + range = bsearch(&s->addr,
> + addrmap, addrmap_num, sizeof(*addrmap), &addrmap_compare);
> + if (range)
> + s->module = builtin_module_offsets[range->module];
> + else
> + s->module = 0;
> +
> /* include the type field in the symbol name, so that it gets
> * compressed together */
> s->len = strlen(sym) + 1;
> @@ -469,6 +588,19 @@ static void write_src(void)
> for (i = 0; i < 256; i++)
> printf("\t.short\t%d\n", best_idx[i]);
> printf("\n");
> +
> + output_label("kallsyms_modules");
> + for (i = 0; i < builtin_module_len; i++)
> + printf("\t.asciz\t\"%s\"\n", builtin_modules[i]);
> + printf("\n");
> +
> + for (i = 0; i < builtin_module_len; i++)
> + free(builtin_modules[i]);
> +
> + output_label("kallsyms_symbol_modules");
> + for (i = 0; i < table_cnt; i++)
> + printf("\t.int\t%d\n", table[i].module);
> + printf("\n");
> }
>
>
> @@ -734,12 +866,169 @@ static void record_relative_base(void)
> }
> }
>
> +/*
> + * Reallocate the builtin modules list.
> + */
> +static void realloc_builtin_modules(void)
> +{
> + builtin_module_size += 50;
> +
> + builtin_modules = realloc(builtin_modules,
> + sizeof(*builtin_modules) *
> + builtin_module_size);
> + builtin_module_offsets = realloc(builtin_module_offsets,
> + sizeof(*builtin_module_offsets) *
> + builtin_module_size);
> +
> + if (!builtin_modules || !builtin_module_offsets) {
> + fprintf(stderr, "kallsyms failure: out of memory.\n");
> + exit(EXIT_FAILURE);
> + }
> +}
> +
> +/*
> + * Add a single built-in module (possibly composed of many files) to the
> + * modules list. Take the offset of the current module and return it
> + * (purely for simplicity's sake in the caller).
> + */
> +static size_t add_builtin_module(const char *module_name, char **module_paths,
> + size_t offset)
> +{
> + /* map the module's object paths to the module offset */
> + while (*module_paths) {
> + obj2mod_put(*module_paths, builtin_module_len);
> + module_paths++;
> + }
> +
> + /* add the module name */
> + if (builtin_module_size <= builtin_module_len)
> + realloc_builtin_modules();
> + builtin_modules[builtin_module_len] = strdup(module_name);
> + builtin_module_offsets[builtin_module_len] = offset;
> + builtin_module_len++;
> +
> + return (offset + strlen(module_name) + 1);
> +}
> +
> +/*
> + * Read the linker map.
> + */
> +static void read_linker_map(void)
> +{
> + unsigned long long addr, size;
> + char obj[PATH_MAX+1];
> + FILE *f = fopen(".tmp_vmlinux.ranges", "r");
> +
> + if (!f) {
> + fprintf(stderr, "Cannot open '.tmp_vmlinux.ranges'.\n");
> + exit(1);
> + }
> +
> + addrmap_num = 0;
> + addrmap_alloced = 4096;
> + addrmap = malloc(sizeof(*addrmap) * addrmap_alloced);
> + if (!addrmap)
> + goto oom;
> +
> + /*
> + * For each address range (addr,size) and object, add to addrmap
> + * the range and the built-in module to which the object maps.
> + */
> + while (fscanf(f, "%llx %llx %s\n", &addr, &size, obj) == 3) {
> + int m = obj2mod_get(obj);
> +
> + if (addr == 0 || size == 0 || m == 0)
> + continue;
> +
> + if (addrmap_num >= addrmap_alloced) {
> + addrmap_alloced *= 2;
> + addrmap = realloc(addrmap,
> + sizeof(*addrmap) * addrmap_alloced);
> + if (!addrmap)
> + goto oom;
> + }
> +
> + addrmap[addrmap_num].addr = addr;
> + addrmap[addrmap_num].size = size;
> + addrmap[addrmap_num].module = m;
> + addrmap_num++;
> + }
> + fclose(f);
> + return;
> +
> +oom:
> + fprintf(stderr, "kallsyms: out of memory\n");
> + exit(1);
> +}
> +
> +/*
> + * Read "modules_thick.builtin" (the list of built-in modules). Construct:
> + * - builtin_modules: array of built-in-module names
> + * - builtin_module_offsets: array of offsets that will later be
> + * used to access a concatenated list of built-in-module names
> + * - obj2mod: a temporary, many-to-one, hash mapping
> + * from object-file paths to built-in-module names
> + * Read ".tmp_vmlinux.ranges" (the linker map).
> + * - addrmap[] maps address ranges to built-in module names (using obj2mod)
> + */
> +static void read_modules(void)
> +{
> + FILE *f;
> + char *line;
> + size_t line_size;
> + size_t offset = 0;
> +
> + realloc_builtin_modules(); /* initial allocation */
> +
> + builtin_modules[0] = strdup(""); /* a symbol that cannot be modular */
> + builtin_module_offsets[0] = 0;
> + builtin_module_len = 1;
> + offset++;
> +
> + /*
> + * Iterate over all modules in modules_thick.builtin and add each.
> + */
> + f = fopen("modules_thick.builtin", "r");
> + if (f == NULL) {
> + fprintf(stderr, "Cannot open modules_thick.builtin: %s\n",
> + strerror(errno));
> + exit(1);
> + }
> +
> + while (getline(&line, &line_size, f) > 0) {
> + char **paths;
> + char *module_name = NULL;
> +
> + paths = modules_thick_parse(line, &module_name);
> + if (paths == NULL)
> + break;
> + offset = add_builtin_module(module_name, paths, offset);
> + free(paths);
> + free(module_name);
> + }
> + if (ferror(f)) {
> + fprintf(stderr, "Error reading from modules_thick file: %s\n",
> + strerror(errno));
> + exit(1);
> + }
> +
> + fclose(f);
> + free(line);
> +
> + /*
> + * Read linker map.
> + */
> + read_linker_map();
> +
> + obj2mod_free();
> +}
> +
> int main(int argc, char **argv)
> {
> if (argc >= 2) {
> int i;
> for (i = 1; i < argc; i++) {
> - if(strcmp(argv[i], "--all-symbols") == 0)
> + if (strcmp(argv[i], "--all-symbols") == 0)
> all_symbols = 1;
> else if (strcmp(argv[i], "--absolute-percpu") == 0)
> absolute_percpu = 1;
> @@ -751,6 +1040,7 @@ int main(int argc, char **argv)
> } else if (argc != 1)
> usage();
>
> + read_modules();
> read_map(stdin);
> shrink_table();
> if (absolute_percpu)
> diff --git a/scripts/link-vmlinux.sh b/scripts/link-vmlinux.sh
> index 436379940356..ac14d292387a 100755
> --- a/scripts/link-vmlinux.sh
> +++ b/scripts/link-vmlinux.sh
> @@ -76,6 +76,7 @@ vmlinux_link()
> --start-group \
> ${KBUILD_VMLINUX_LIBS} \
> --end-group \
> + -Map=.tmp_vmlinux.map \
> ${@}"
>
> ${LD} ${KBUILD_LDFLAGS} ${LDFLAGS_vmlinux} \
> @@ -88,6 +89,7 @@ vmlinux_link()
> -Wl,--start-group \
> ${KBUILD_VMLINUX_LIBS} \
> -Wl,--end-group \
> + -Wl,-Map=.tmp_vmlinux.map \
> ${@}"
>
> ${CC} ${CFLAGS_vmlinux} \
> @@ -140,6 +142,19 @@ kallsyms()
> info KSYM ${2}
> local kallsymopt;
>
> + # read the linker map to identify ranges of addresses:
> + # - for each *.o file, report address, size, pathname
> + # - most such lines will have four fields
> + # - but sometimes there is a line break after the first field
> + # - start reading at "Linker script and memory map"
> + # - stop reading at ".brk"
> + ${AWK} '
> + /\.o$/ && start==1 && NF>=3 { print $(NF-2), $(NF-1), $NF }
> + /^Linker script and memory map/ { start = 1 }
> + /^\.brk/ { exit(0) }
> + ' .tmp_vmlinux.map | sort > .tmp_vmlinux.ranges
> +
> + # get kallsyms options
> if [ -n "${CONFIG_KALLSYMS_ALL}" ]; then
> kallsymopt="${kallsymopt} --all-symbols"
> fi
> @@ -152,11 +167,13 @@ kallsyms()
> kallsymopt="${kallsymopt} --base-relative"
> fi
>
> + # set up compilation
> local aflags="${KBUILD_AFLAGS} ${KBUILD_AFLAGS_KERNEL} \
> ${NOSTDINC_FLAGS} ${LINUXINCLUDE} ${KBUILD_CPPFLAGS}"
>
> local afile="`basename ${2} .o`.S"
>
> + # construct file and compile
> ${NM} -n ${1} | scripts/kallsyms ${kallsymopt} > ${afile}
> ${CC} ${aflags} -c -o ${2} ${afile}
> }
> diff --git a/scripts/modules_thick.c b/scripts/modules_thick.c
> new file mode 100644
> index 000000000000..2d33b92060f9
> --- /dev/null
> +++ b/scripts/modules_thick.c
> @@ -0,0 +1,104 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * A simple modules_thick reader.
> + *
> + * (C) 2014, 2019 Oracle, Inc. All rights reserved.
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License as published by
> + * the Free Software Foundation; either version 2 of the License, or
> + * (at your option) any later version.
> + */
> +
> +#include <errno.h>
> +#include <stdio.h>
> +#include <stdlib.h>
> +#include <string.h>
> +
> +#include "modules_thick.h"
> +
> +/*
> + * Parse a line from "modules_thick.builtin". Allocate and return a module name
> + * and a null-terminated array of object paths (file names). The name and array
> + * should be freed by the caller; the strings the array points to are in "line".
> + *
> + * Modules can consist of multiple paths: in this case, the portion before the
> + * colon is the path to the module, while the portion after the colon is a
> + * space-separated list of object paths. In this case, the portion before the
> + * colon is an "object file" that does not actually exist: it is merged into
> + * built-in.a without ever being written out.
> + */
> +char ** __attribute__((__nonnull__))
> +modules_thick_parse(char *line, char **module_name)
> +{
> + size_t npaths = 1;
> + char **paths;
> + char *tmp;
> + char *olist;
> +
> + /* find object-file list after the colon, if any */
> + olist = strchr(line, ':');
> + if (olist != NULL) {
> + *olist = '\0';
> + olist++;
> + olist += strspn(olist, " \n");
> + if (*olist != '\0') {
> + /* replace any trailing \n with \0 */
> + tmp = strchr(olist, '\n');
> + if (tmp != NULL)
> + *tmp = '\0';
> + } else
> + olist = NULL;
> + }
> +
> + /* get pathless module_name, starting after the last '/', if any */
> + tmp = strrchr(line, '/');
> + *module_name = strdup(tmp ? tmp + 1 : line);
> +
> + /* replace '-' with '_' as is done to names when built as modules */
> + for (tmp = *module_name; *tmp != '\0'; tmp++)
> + if (*tmp == '-')
> + *tmp = '_';
> +
> + /* terminate at the last '.' to remove any suffix */
> + tmp = strrchr(*module_name, '.');
> + if (tmp != NULL)
> + *tmp = '\0';
> +
> + /*
> + * Count the number of paths by counting the number of spaces.
> + * This could be an overestimate.
> + */
> + if (olist) {
> + npaths = 0;
> + for (tmp = olist; tmp != NULL; tmp = strchr(tmp + 1, ' '))
> + npaths++;
> + }
> +
> + paths = malloc((npaths + 1) * sizeof(char *));
> + if (!paths) {
> + fprintf(stderr, "%s: out of memory\n", __func__);
> + exit(1);
> + }
> +
> + /* copy the paths in */
> + if (olist) {
> + size_t i = 0;
> +
> + while ((tmp = strsep(&olist, " ")) != NULL) {
> + if (i >= npaths) {
> + fprintf(stderr,
> + "%s bug: npaths overflow on module %s\n",
> + __func__, *module_name);
> + exit(1);
> + }
> + paths[i++] = tmp;
> + }
> + npaths = i;
> + } else
> + paths[0] = line; /* untransformed module name */
> +
> + paths[npaths] = NULL;
> +
> + return paths;
> +}
> diff --git a/scripts/modules_thick.h b/scripts/modules_thick.h
> new file mode 100644
> index 000000000000..7e2c0309c731
> --- /dev/null
> +++ b/scripts/modules_thick.h
> @@ -0,0 +1,27 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +/*
> + * A simple modules_thick reader.
> + *
> + * (C) 2014, 2019 Oracle, Inc. All rights reserved.
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License as published by
> + * the Free Software Foundation; either version 2 of the License, or
> + * (at your option) any later version.
> + */
> +
> +#ifndef _LINUX_MODULES_THICK_H
> +#define _LINUX_MODULES_THICK_H
> +
> +#include <stdio.h>
> +#include <stddef.h>
> +
> +/*
> + * Parse a line from "modules_thick.builtin". Return a module name
> + * and a null-terminated array of object paths (file names).
> + */
> +
> +char ** __attribute__((__nonnull__))
> +modules_thick_parse(char *line, char **module_name);
> +
> +#endif
> diff --git a/scripts/namespace.pl b/scripts/namespace.pl
> index 1da7bca201a4..4c7615e720de 100755
> --- a/scripts/namespace.pl
> +++ b/scripts/namespace.pl
> @@ -120,6 +120,11 @@ my %nameexception = (
> 'kallsyms_addresses'=> 1,
> 'kallsyms_offsets' => 1,
> 'kallsyms_relative_base'=> 1,
> + 'kallsyms_token_table'=> 1,
> + 'kallsyms_token_index'=> 1,
> + 'kallsyms_markers' => 1,
> + 'kallsyms_modules' => 1,
> + 'kallsyms_symbol_modules'=> 1,
> '__this_module' => 1,
> '_etext' => 1,
> '_edata' => 1,