diff options
| -rw-r--r-- | .gitignore | 1 | ||||
| -rw-r--r-- | Documentation/dontdiff | 1 | ||||
| -rw-r--r-- | Documentation/kbuild/kbuild.rst | 5 | ||||
| -rw-r--r-- | Documentation/process/changes.rst | 7 | ||||
| -rw-r--r-- | Makefile | 1 | ||||
| -rw-r--r-- | lib/Kconfig.debug | 15 | ||||
| -rw-r--r-- | scripts/Makefile.vmlinux | 18 | ||||
| -rw-r--r-- | scripts/Makefile.vmlinux_o | 3 | ||||
| -rwxr-xr-x | scripts/generate_builtin_ranges.awk | 508 |
9 files changed, 559 insertions, 0 deletions
diff --git a/.gitignore b/.gitignore index c06a3ef6d6c6..625bf59ad845 100644 --- a/.gitignore +++ b/.gitignore @@ -69,6 +69,7 @@ modules.order /Module.markers /modules.builtin /modules.builtin.modinfo +/modules.builtin.ranges /modules.nsdeps # diff --git a/Documentation/dontdiff b/Documentation/dontdiff index 3c399f132e2d..a867aea95c40 100644 --- a/Documentation/dontdiff +++ b/Documentation/dontdiff @@ -180,6 +180,7 @@ modpost modules-only.symvers modules.builtin modules.builtin.modinfo +modules.builtin.ranges modules.nsdeps modules.order modversions.h* diff --git a/Documentation/kbuild/kbuild.rst b/Documentation/kbuild/kbuild.rst index 9c8d1d046ea5..a0f7726c46f8 100644 --- a/Documentation/kbuild/kbuild.rst +++ b/Documentation/kbuild/kbuild.rst @@ -22,6 +22,11 @@ modules.builtin.modinfo This file contains modinfo from all modules that are built into the kernel. Unlike modinfo of a separate module, all fields are prefixed with module name. +modules.builtin.ranges +---------------------- +This file contains address offset ranges (per ELF section) for all modules +that are built into the kernel. Together with System.map, it can be used +to associate module names with symbols. Environment variables ===================== diff --git a/Documentation/process/changes.rst b/Documentation/process/changes.rst index 3fc63f27c226..00f1ed7c59c3 100644 --- a/Documentation/process/changes.rst +++ b/Documentation/process/changes.rst @@ -64,6 +64,7 @@ GNU tar 1.28 tar --version gtags (optional) 6.6.5 gtags --version mkimage (optional) 2017.01 mkimage --version Python (optional) 3.5.x python3 --version +GNU AWK (optional) 5.1.0 gawk --version ====================== =============== ======================================== .. [#f1] Sphinx is needed only to build the Kernel documentation @@ -192,6 +193,12 @@ platforms. The tool is available via the ``u-boot-tools`` package or can be built from the U-Boot source code. See the instructions at https://docs.u-boot.org/en/latest/build/tools.html#building-tools-for-linux +GNU AWK +------- + +GNU AWK is needed if you want kernel builds to generate address range data for +builtin modules (CONFIG_BUILTIN_MODULE_RANGES). + System utilities **************** @@ -1482,6 +1482,7 @@ endif # CONFIG_MODULES # Directories & files removed with 'make clean' CLEAN_FILES += vmlinux.symvers modules-only.symvers \ modules.builtin modules.builtin.modinfo modules.nsdeps \ + modules.builtin.ranges vmlinux.o.map \ compile_commands.json rust/test \ rust-project.json .vmlinux.objs .vmlinux.export.c diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index a30c03a66172..5e2f30921cb2 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -571,6 +571,21 @@ config VMLINUX_MAP pieces of code get eliminated with CONFIG_LD_DEAD_CODE_DATA_ELIMINATION. +config BUILTIN_MODULE_RANGES + bool "Generate address range information for builtin modules" + depends on !LTO + depends on VMLINUX_MAP + help + When modules are built into the kernel, there will be no module name + associated with its symbols in /proc/kallsyms. Tracers may want to + identify symbols by module name and symbol name regardless of whether + the module is configured as loadable or not. + + This option generates modules.builtin.ranges in the build tree with + offset ranges (per ELF section) for the module(s) they belong to. + It also records an anchor symbol to determine the load address of the + section. + config DEBUG_FORCE_WEAK_PER_CPU bool "Force weak per-cpu definitions" depends on DEBUG_KERNEL diff --git a/scripts/Makefile.vmlinux b/scripts/Makefile.vmlinux index 5ceecbed31eb..1284f05555b9 100644 --- a/scripts/Makefile.vmlinux +++ b/scripts/Makefile.vmlinux @@ -33,6 +33,24 @@ targets += vmlinux vmlinux: scripts/link-vmlinux.sh vmlinux.o $(KBUILD_LDS) FORCE +$(call if_changed_dep,link_vmlinux) +# module.builtin.ranges +# --------------------------------------------------------------------------- +ifdef CONFIG_BUILTIN_MODULE_RANGES +__default: modules.builtin.ranges + +quiet_cmd_modules_builtin_ranges = GEN $@ + cmd_modules_builtin_ranges = gawk -f $(real-prereqs) > $@ + +targets += modules.builtin.ranges +modules.builtin.ranges: $(srctree)/scripts/generate_builtin_ranges.awk \ + modules.builtin vmlinux.map vmlinux.o.map FORCE + $(call if_changed,modules_builtin_ranges) + +vmlinux.map: vmlinux + @: + +endif + # Add FORCE to the prerequisites of a target to force it to be always rebuilt. # --------------------------------------------------------------------------- diff --git a/scripts/Makefile.vmlinux_o b/scripts/Makefile.vmlinux_o index d64070b6b4bc..0b6e2ebf60dc 100644 --- a/scripts/Makefile.vmlinux_o +++ b/scripts/Makefile.vmlinux_o @@ -45,9 +45,12 @@ objtool-args = $(vmlinux-objtool-args-y) --link # Link of vmlinux.o used for section mismatch analysis # --------------------------------------------------------------------------- +vmlinux-o-ld-args-$(CONFIG_BUILTIN_MODULE_RANGES) += -Map=$@.map + quiet_cmd_ld_vmlinux.o = LD $@ cmd_ld_vmlinux.o = \ $(LD) ${KBUILD_LDFLAGS} -r -o $@ \ + $(vmlinux-o-ld-args-y) \ $(addprefix -T , $(initcalls-lds)) \ --whole-archive vmlinux.a --no-whole-archive \ --start-group $(KBUILD_VMLINUX_LIBS) --end-group \ diff --git a/scripts/generate_builtin_ranges.awk b/scripts/generate_builtin_ranges.awk new file mode 100755 index 000000000000..b9ec761b3bef --- /dev/null +++ b/scripts/generate_builtin_ranges.awk @@ -0,0 +1,508 @@ +#!/usr/bin/gawk -f +# SPDX-License-Identifier: GPL-2.0 +# generate_builtin_ranges.awk: Generate address range data for builtin modules +# Written by Kris Van Hees <kris.van.hees@oracle.com> +# +# Usage: generate_builtin_ranges.awk modules.builtin vmlinux.map \ +# vmlinux.o.map > modules.builtin.ranges +# + +# Return the module name(s) (if any) associated with the given object. +# +# If we have seen this object before, return information from the cache. +# Otherwise, retrieve it from the corresponding .cmd file. +# +function get_module_info(fn, mod, obj, s) { + if (fn in omod) + return omod[fn]; + + if (match(fn, /\/[^/]+$/) == 0) + return ""; + + obj = fn; + mod = ""; + fn = substr(fn, 1, RSTART) "." substr(fn, RSTART + 1) ".cmd"; + if (getline s <fn == 1) { + if (match(s, /DKBUILD_MODFILE=['"]+[^'"]+/) > 0) { + mod = substr(s, RSTART + 16, RLENGTH - 16); + gsub(/['"]/, "", mod); + } else if (match(s, /RUST_MODFILE=[^ ]+/) > 0) + mod = substr(s, RSTART + 13, RLENGTH - 13); + } + close(fn); + + # A single module (common case) also reflects objects that are not part + # of a module. Some of those objects have names that are also a module + # name (e.g. core). We check the associated module file name, and if + # they do not match, the object is not part of a module. + if (mod !~ / /) { + if (!(mod in mods)) + mod = ""; + } + + gsub(/([^/ ]*\/)+/, "", mod); + gsub(/-/, "_", mod); + + # At this point, mod is a single (valid) module name, or a list of + # module names (that do not need validation). + omod[obj] = mod; + + return mod; +} + +# Update the ranges entry for the given module 'mod' in section 'osect'. +# +# We use a modified absolute start address (soff + base) as index because we +# may need to insert an anchor record later that must be at the start of the +# section data, and the first module may very well start at the same address. +# So, we use (addr << 1) + 1 to allow a possible anchor record to be placed at +# (addr << 1). This is safe because the index is only used to sort the entries +# before writing them out. +# +function update_entry(osect, mod, soff, eoff, sect, idx) { + sect = sect_in[osect]; + idx = sprintf("%016x", (soff + sect_base[osect]) * 2 + 1); + entries[idx] = sprintf("%s %08x-%08x %s", sect, soff, eoff, mod); + count[sect]++; +} + +# (1) Build a lookup map of built-in module names. +# +# The first file argument is used as input (modules.builtin). +# +# Lines will be like: +# kernel/crypto/lzo-rle.ko +# and we record the object name "crypto/lzo-rle". +# +ARGIND == 1 { + sub(/kernel\//, ""); # strip off "kernel/" prefix + sub(/\.ko$/, ""); # strip off .ko suffix + + mods[$1] = 1; + next; +} + +# (2) Collect address information for each section. +# +# The second file argument is used as input (vmlinux.map). +# +# We collect the base address of the section in order to convert all addresses +# in the section into offset values. +# +# We collect the address of the anchor (or first symbol in the section if there +# is no explicit anchor) to allow users of the range data to calculate address +# ranges based on the actual load address of the section in the running kernel. +# +# We collect the start address of any sub-section (section included in the top +# level section being processed). This is needed when the final linking was +# done using vmlinux.a because then the list of objects contained in each +# section is to be obtained from vmlinux.o.map. The offset of the sub-section +# is recorded here, to be used as an addend when processing vmlinux.o.map +# later. +# + +# Both GNU ld and LLVM lld linker map format are supported by converting LLVM +# lld linker map records into equivalent GNU ld linker map records. +# +# The first record of the vmlinux.map file provides enough information to know +# which format we are dealing with. +# +ARGIND == 2 && FNR == 1 && NF == 7 && $1 == "VMA" && $7 == "Symbol" { + map_is_lld = 1; + if (dbg) + printf "NOTE: %s uses LLVM lld linker map format\n", FILENAME >"/dev/stderr"; + next; +} + +# (LLD) Convert a section record fronm lld format to ld format. +# +# lld: ffffffff82c00000 2c00000 2493c0 8192 .data +# -> +# ld: .data 0xffffffff82c00000 0x2493c0 load address 0x0000000002c00000 +# +ARGIND == 2 && map_is_lld && NF == 5 && /[0-9] [^ ]+$/ { + $0 = $5 " 0x"$1 " 0x"$3 " load address 0x"$2; +} + +# (LLD) Convert an anchor record from lld format to ld format. +# +# lld: ffffffff81000000 1000000 0 1 _text = . +# -> +# ld: 0xffffffff81000000 _text = . +# +ARGIND == 2 && map_is_lld && !anchor && NF == 7 && raw_addr == "0x"$1 && $6 == "=" && $7 == "." { + $0 = " 0x"$1 " " $5 " = ."; +} + +# (LLD) Convert an object record from lld format to ld format. +# +# lld: 11480 11480 1f07 16 vmlinux.a(arch/x86/events/amd/uncore.o):(.text) +# -> +# ld: .text 0x0000000000011480 0x1f07 arch/x86/events/amd/uncore.o +# +ARGIND == 2 && map_is_lld && NF == 5 && $5 ~ /:\(/ { + gsub(/\)/, ""); + sub(/ vmlinux\.a\(/, " "); + sub(/:\(/, " "); + $0 = " "$6 " 0x"$1 " 0x"$3 " " $5; +} + +# (LLD) Convert a symbol record from lld format to ld format. +# +# We only care about these while processing a section for which no anchor has +# been determined yet. +# +# lld: ffffffff82a859a4 2a859a4 0 1 btf_ksym_iter_id +# -> +# ld: 0xffffffff82a859a4 btf_ksym_iter_id +# +ARGIND == 2 && map_is_lld && sect && !anchor && NF == 5 && $5 ~ /^[_A-Za-z][_A-Za-z0-9]*$/ { + $0 = " 0x"$1 " " $5; +} + +# (LLD) We do not need any other ldd linker map records. +# +ARGIND == 2 && map_is_lld && /^[0-9a-f]{16} / { + next; +} + +# (LD) Section records with just the section name at the start of the line +# need to have the next line pulled in to determine whether it is a +# loadable section. If it is, the next line will contains a hex value +# as first and second items. +# +ARGIND == 2 && !map_is_lld && NF == 1 && /^[^ ]/ { + s = $0; + getline; + if ($1 !~ /^0x/ || $2 !~ /^0x/) + next; + + $0 = s " " $0; +} + +# (LD) Object records with just the section name denote records with a long +# section name for which the remainder of the record can be found on the +# next line. +# +# (This is also needed for vmlinux.o.map, when used.) +# +ARGIND >= 2 && !map_is_lld && NF == 1 && /^ [^ \*]/ { + s = $0; + getline; + $0 = s " " $0; +} + +# Beginning a new section - done with the previous one (if any). +# +ARGIND == 2 && /^[^ ]/ { + sect = 0; +} + +# Process a loadable section (we only care about .-sections). +# +# Record the section name and its base address. +# We also record the raw (non-stripped) address of the section because it can +# be used to identify an anchor record. +# +# Note: +# Since some AWK implementations cannot handle large integers, we strip off the +# first 4 hex digits from the address. This is safe because the kernel space +# is not large enough for addresses to extend into those digits. The portion +# to strip off is stored in addr_prefix as a regexp, so further clauses can +# perform a simple substitution to do the address stripping. +# +ARGIND == 2 && /^\./ { + # Explicitly ignore a few sections that are not relevant here. + if ($1 ~ /^\.orc_/ || $1 ~ /_sites$/ || $1 ~ /\.percpu/) + next; + + # Sections with a 0-address can be ignored as well. + if ($2 ~ /^0x0+$/) + next; + + raw_addr = $2; + addr_prefix = "^" substr($2, 1, 6); + base = $2; + sub(addr_prefix, "0x", base); + base = strtonum(base); + sect = $1; + anchor = 0; + sect_base[sect] = base; + sect_size[sect] = strtonum($3); + + if (dbg) + printf "[%s] BASE %016x\n", sect, base >"/dev/stderr"; + + next; +} + +# If we are not in a section we care about, we ignore the record. +# +ARGIND == 2 && !sect { + next; +} + +# Record the first anchor symbol for the current section. +# +# An anchor record for the section bears the same raw address as the section +# record. +# +ARGIND == 2 && !anchor && NF == 4 && raw_addr == $1 && $3 == "=" && $4 == "." { + anchor = sprintf("%s %08x-%08x = %s", sect, 0, 0, $2); + sect_anchor[sect] = anchor; + + if (dbg) + printf "[%s] ANCHOR %016x = %s (.)\n", sect, 0, $2 >"/dev/stderr"; + + next; +} + +# If no anchor record was found for the current section, use the first symbol +# in the section as anchor. +# +ARGIND == 2 && !anchor && NF == 2 && $1 ~ /^0x/ && $2 !~ /^0x/ { + addr = $1; + sub(addr_prefix, "0x", addr); + addr = strtonum(addr) - base; + anchor = sprintf("%s %08x-%08x = %s", sect, addr, addr, $2); + sect_anchor[sect] = anchor; + + if (dbg) + printf "[%s] ANCHOR %016x = %s\n", sect, addr, $2 >"/dev/stderr"; + + next; +} + +# The first occurrence of a section name in an object record establishes the +# addend (often 0) for that section. This information is needed to handle +# sections that get combined in the final linking of vmlinux (e.g. .head.text +# getting included at the start of .text). +# +# If the section does not have a base yet, use the base of the encapsulating +# section. +# +ARGIND == 2 && sect && NF == 4 && /^ [^ \*]/ && !($1 in sect_addend) { + if (!($1 in sect_base)) { + sect_base[$1] = base; + + if (dbg) + printf "[%s] BASE %016x\n", $1, base >"/dev/stderr"; + } + + addr = $2; + sub(addr_prefix, "0x", addr); + addr = strtonum(addr); + sect_addend[$1] = addr - sect_base[$1]; + sect_in[$1] = sect; + + if (dbg) + printf "[%s] ADDEND %016x - %016x = %016x\n", $1, addr, base, sect_addend[$1] >"/dev/stderr"; + + # If the object is vmlinux.o then we will need vmlinux.o.map to get the + # actual offsets of objects. + if ($4 == "vmlinux.o") + need_o_map = 1; +} + +# (3) Collect offset ranges (relative to the section base address) for built-in +# modules. +# +# If the final link was done using the actual objects, vmlinux.map contains all +# the information we need (see section (3a)). +# If linking was done using vmlinux.a as intermediary, we will need to process +# vmlinux.o.map (see section (3b)). + +# (3a) Determine offset range info using vmlinux.map. +# +# Since we are already processing vmlinux.map, the top level section that is +# being processed is already known. If we do not have a base address for it, +# we do not need to process records for it. +# +# Given the object name, we determine the module(s) (if any) that the current +# object is associated with. +# +# If we were already processing objects for a (list of) module(s): +# - If the current object belongs to the same module(s), update the range data +# to include the current object. +# - Otherwise, ensure that the end offset of the range is valid. +# +# If the current object does not belong to a built-in module, ignore it. +# +# If it does, we add a new built-in module offset range record. +# +ARGIND == 2 && !need_o_map && /^ [^ ]/ && NF == 4 && $3 != "0x0" { + if (!(sect in sect_base)) + next; + + # Turn the address into an offset from the section base. + soff = $2; + sub(addr_prefix, "0x", soff); + soff = strtonum(soff) - sect_base[sect]; + eoff = soff + strtonum($3); + + # Determine which (if any) built-in modules the object belongs to. + mod = get_module_info($4); + + # If we are processing a built-in module: + # - If the current object is within the same module, we update its + # entry by extending the range and move on + # - Otherwise: + # + If we are still processing within the same main section, we + # validate the end offset against the start offset of the + # current object (e.g. .rodata.str1.[18] objects are often + # listed with an incorrect size in the linker map) + # + Otherwise, we validate the end offset against the section + # size + if (mod_name) { + if (mod == mod_name) { + mod_eoff = eoff; + update_entry(mod_sect, mod_name, mod_soff, eoff); + + next; + } else if (sect == sect_in[mod_sect]) { + if (mod_eoff > soff) + update_entry(mod_sect, mod_name, mod_soff, soff); + } else { + v = sect_size[sect_in[mod_sect]]; + if (mod_eoff > v) + update_entry(mod_sect, mod_name, mod_soff, v); + } + } + + mod_name = mod; + + # If we encountered an object that is not part of a built-in module, we + # do not need to record any data. + if (!mod) + next; + + # At this point, we encountered the start of a new built-in module. + mod_name = mod; + mod_soff = soff; + mod_eoff = eoff; + mod_sect = $1; + update_entry($1, mod, soff, mod_eoff); + + next; +} + +# If we do not need to parse the vmlinux.o.map file, we are done. +# +ARGIND == 3 && !need_o_map { + if (dbg) + printf "Note: %s is not needed.\n", FILENAME >"/dev/stderr"; + exit; +} + +# (3) Collect offset ranges (relative to the section base address) for built-in +# modules. +# + +# (LLD) Convert an object record from lld format to ld format. +# +ARGIND == 3 && map_is_lld && NF == 5 && $5 ~ /:\(/ { + gsub(/\)/, ""); + sub(/:\(/, " "); + + sect = $6; + if (!(sect in sect_addend)) + next; + + sub(/ vmlinux\.a\(/, " "); + $0 = " "sect " 0x"$1 " 0x"$3 " " $5; +} + +# (3b) Determine offset range info using vmlinux.o.map. +# +# If we do not know an addend for the object's section, we are interested in +# anything within that section. +# +# Determine the top-level section that the object's section was included in +# during the final link. This is the section name offset range data will be +# associated with for this object. +# +# The remainder of the processing of the current object record follows the +# procedure outlined in (3a). +# +ARGIND == 3 && /^ [^ ]/ && NF == 4 && $3 != "0x0" { + osect = $1; + if (!(osect in sect_addend)) + next; + + # We need to work with the main section. + sect = sect_in[osect]; + + # Turn the address into an offset from the section base. + soff = $2; + sub(addr_prefix, "0x", soff); + soff = strtonum(soff) + sect_addend[osect]; + eoff = soff + strtonum($3); + + # Determine which (if any) built-in modules the object belongs to. + mod = get_module_info($4); + + # If we are processing a built-in module: + # - If the current object is within the same module, we update its + # entry by extending the range and move on + # - Otherwise: + # + If we are still processing within the same main section, we + # validate the end offset against the start offset of the + # current object (e.g. .rodata.str1.[18] objects are often + # listed with an incorrect size in the linker map) + # + Otherwise, we validate the end offset against the section + # size + if (mod_name) { + if (mod == mod_name) { + mod_eoff = eoff; + update_entry(mod_sect, mod_name, mod_soff, eoff); + + next; + } else if (sect == sect_in[mod_sect]) { + if (mod_eoff > soff) + update_entry(mod_sect, mod_name, mod_soff, soff); + } else { + v = sect_size[sect_in[mod_sect]]; + if (mod_eoff > v) + update_entry(mod_sect, mod_name, mod_soff, v); + } + } + + mod_name = mod; + + # If we encountered an object that is not part of a built-in module, we + # do not need to record any data. + if (!mod) + next; + + # At this point, we encountered the start of a new built-in module. + mod_name = mod; + mod_soff = soff; + mod_eoff = eoff; + mod_sect = osect; + update_entry(osect, mod, soff, mod_eoff); + + next; +} + +# (4) Generate the output. +# +# Anchor records are added for each section that contains offset range data +# records. They are added at an adjusted section base address (base << 1) to +# ensure they come first in the second records (see update_entry() above for +# more information). +# +# All entries are sorted by (adjusted) address to ensure that the output can be +# parsed in strict ascending address order. +# +END { + for (sect in count) { + if (sect in sect_anchor) { + idx = sprintf("%016x", sect_base[sect] * 2); + entries[idx] = sect_anchor[sect]; + } + } + + n = asorti(entries, indices); + for (i = 1; i <= n; i++) + print entries[indices[i]]; +} |