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2023-07-29scripts/kallsyms: Fix build failure by setting errno before calling getline()James Clark1-0/+1
getline() returns -1 at EOF as well as on error. It also doesn't set errno to 0 on success, so initialize it to 0 before using errno to check for an error condition. See the paragraph here [1]: For some system calls and library functions (e.g., getpriority(2)), -1 is a valid return on success. In such cases, a successful return can be distinguished from an error return by setting errno to zero before the call, and then, if the call returns a status that indicates that an error may have occurred, checking to see if errno has a nonzero value. Bear has a bug [2] that launches processes with errno set and causes the following build failure: $ bear -- make LLVM=1 ... LD .tmp_vmlinux.kallsyms1 NM .tmp_vmlinux.kallsyms1.syms KSYMS .tmp_vmlinux.kallsyms1.S read_symbol: Invalid argument [1]: https://linux.die.net/man/3/errno [2]: https://github.com/rizsotto/Bear/issues/469 Fixes: 1c975da56a6f ("scripts/kallsyms: remove KSYM_NAME_LEN_BUFFER") Reviewed-by: Miguel Ojeda <ojeda@kernel.org> Signed-off-by: James Clark <james.clark@arm.com> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2023-07-13kallsyms: strip LTO-only suffixes from promoted global functionsYonghong Song1-3/+3
Commit 6eb4bd92c1ce ("kallsyms: strip LTO suffixes from static functions") stripped all function/variable suffixes started with '.' regardless of whether those suffixes are generated at LTO mode or not. In fact, as far as I know, in LTO mode, when a static function/variable is promoted to the global scope, '.llvm.<...>' suffix is added. The existing mechanism breaks live patch for a LTO kernel even if no <symbol>.llvm.<...> symbols are involved. For example, for the following kernel symbols: $ grep bpf_verifier_vlog /proc/kallsyms ffffffff81549f60 t bpf_verifier_vlog ffffffff8268b430 d bpf_verifier_vlog._entry ffffffff8282a958 d bpf_verifier_vlog._entry_ptr ffffffff82e12a1f d bpf_verifier_vlog.__already_done 'bpf_verifier_vlog' is a static function. '_entry', '_entry_ptr' and '__already_done' are static variables used inside 'bpf_verifier_vlog', so llvm promotes them to file-level static with prefix 'bpf_verifier_vlog.'. Note that the func-level to file-level static function promotion also happens without LTO. Given a symbol name 'bpf_verifier_vlog', with LTO kernel, current mechanism will return 4 symbols to live patch subsystem which current live patching subsystem cannot handle it. With non-LTO kernel, only one symbol is returned. In [1], we have a lengthy discussion, the suggestion is to separate two cases: (1). new symbols with suffix which are generated regardless of whether LTO is enabled or not, and (2). new symbols with suffix generated only when LTO is enabled. The cleanup_symbol_name() should only remove suffixes for case (2). Case (1) should not be changed so it can work uniformly with or without LTO. This patch removed LTO-only suffix '.llvm.<...>' so live patching and tracing should work the same way for non-LTO kernel. The cleanup_symbol_name() in scripts/kallsyms.c is also changed to have the same filtering pattern so both kernel and kallsyms tool have the same expectation on the order of symbols. [1] https://lore.kernel.org/live-patching/20230615170048.2382735-1-song@kernel.org/T/#u Fixes: 6eb4bd92c1ce ("kallsyms: strip LTO suffixes from static functions") Reported-by: Song Liu <song@kernel.org> Signed-off-by: Yonghong Song <yhs@fb.com> Reviewed-by: Zhen Lei <thunder.leizhen@huawei.com> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Acked-by: Song Liu <song@kernel.org> Link: https://lore.kernel.org/r/20230628181926.4102448-1-yhs@fb.com Signed-off-by: Kees Cook <keescook@chromium.org>
2023-06-14scripts/kallsyms: remove KSYM_NAME_LEN_BUFFERMasahiro Yamada1-29/+32
You do not need to decide the buffer size statically. Use getline() to grow the line buffer as needed. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Reviewed-by: Nicolas Schier <n.schier@avm.de>
2023-06-14scripts/kallsyms: constify long_optionsMasahiro Yamada1-1/+1
getopt_long() does not modify this. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Reviewed-by: Nicolas Schier <n.schier@avm.de>
2023-04-17scripts/kallsyms: update the usage in the comment blockMasahiro Yamada1-1/+1
Commit 010a0aad39fc ("kallsyms: Correctly sequence symbols when CONFIG_LTO_CLANG=y") added --lto-clang, and updated the usage() function, but not the comment. Update it in the same way. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
2023-04-17scripts/kallsyms: decrease expand_symbol() / cleanup_symbol_name() callsMasahiro Yamada1-18/+15
Currently, expand_symbol() is called many times to get the uncompressed symbol names for sorting, and also for adding comments. With the output order shuffled in the previous commit, the symbol data are now written in the following order: (1) kallsyms_num_syms (2) kallsyms_names <-- need compressed names (3) kallsyms_markers (4) kallsyms_token_table (5) kallsyms_token_index (6) kallsyms_addressed / kallsyms_offsets <-- need uncompressed names (for commenting) (7) kallsyms_relative_base (8) kallsyms_seq_of_names <-- need uncompressed names (for sorting) The compressed names are only needed by (2). Call expand_symbol() between (2) and (3) to restore the original symbol names. This requires just one expand_symbol() call for each symbol. Call cleanup_symbol_name() between (7) and (8) instead of during sorting. It is allowed to overwrite the ->sym field because (8) just outputs the index instead of the name of each symbol. Again, this requires just one cleanup_symbol_name() call for each symbol. This refactoring makes it ~30% faster. [Before] $ time scripts/kallsyms --all-symbols --absolute-percpu --base-relative \ .tmp_vmlinux.kallsyms2.syms >/dev/null real 0m1.027s user 0m1.010s sys 0m0.016s [After] $ time scripts/kallsyms --all-symbols --absolute-percpu --base-relative \ .tmp_vmlinux.kallsyms2.syms >/dev/null real 0m0.717s user 0m0.717s sys 0m0.000s Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2023-04-17scripts/kallsyms: change the output orderMasahiro Yamada1-59/+59
Currently, this tool outputs symbol data in the following order. (1) kallsyms_addressed / kallsyms_offsets (2) kallsyms_relative_base (3) kallsyms_num_syms (4) kallsyms_names (5) kallsyms_markers (6) kallsyms_seq_of_names (7) kallsyms_token_table (8) kallsyms_token_index This commit changes the order as follows: (1) kallsyms_num_syms (2) kallsyms_names (3) kallsyms_markers (4) kallsyms_token_table (5) kallsyms_token_index (6) kallsyms_addressed / kallsyms_offsets (7) kallsyms_relative_base (8) kallsyms_seq_of_names The motivation is to decrease the number of function calls to expand_symbol() and cleanup_symbol_name(). The compressed names are only required for writing 'kallsyms_names'. If you do this first, we can restore the original symbol names. You do not need to repeat the same operation over again. The actual refactoring will happen in the next commit. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2023-04-17scripts/kallsyms: move compiler-generated symbol patterns to mksysmapMasahiro Yamada1-60/+0
scripts/kallsyms.c maintains compiler-generated symbols, but we end up with something similar in scripts/mksysmap to avoid the "Inconsistent kallsyms data" error. For example, commit c17a2538704f ("mksysmap: Fix the mismatch of 'L0' symbols in System.map"). They were separately maintained prior to commit 94ff2f63d6a3 ("kbuild: reuse mksysmap output for kallsyms"). Now that scripts/kallsyms.c parses the output of scripts/mksysmap, it makes more sense to collect all the ignored patterns to mksysmap. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
2023-04-17scripts/kallsyms: exclude symbols generated by itself dynamicallyMasahiro Yamada1-16/+0
Drop the symbols generated by scripts/kallsyms itself automatically instead of maintaining the symbol list manually. Pass the kallsyms object from the previous kallsyms step (if it exists) as the third parameter of scripts/mksysmap, which will weed out the generated symbols from the input to the next kallsyms step. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2023-04-17scripts/kallsyms: remove redundant code for omitting U and NMasahiro Yamada1-4/+1
The symbol types 'U' and 'N' are already filtered out by the following line in scripts/mksysmap: -e ' [aNUw] ' Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
2023-04-17kallsyms: expand symbol name into comment for debuggingArnd Bergmann1-1/+2
The assembler output of kallsyms.c is not meant for people to understand, and is generally not helpful when debugging "Inconsistent kallsyms data" warnings. I have previously struggled with these, but found it helpful to list which symbols changed between the first and second pass in the .tmp_vmlinux.kallsyms*.S files. As this file is preprocessed, it's possible to add a C-style multiline comment with the full type/name tuple. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2023-03-07kallsyms: add kallsyms_seqs_of_names to list of special symbolsArnd Bergmann1-0/+1
My randconfig build setup ran into another kallsyms warning: Inconsistent kallsyms data Try make KALLSYMS_EXTRA_PASS=1 as a workaround After adding some debugging code to kallsyms.c, I saw that the recently added kallsyms_seqs_of_names symbol can sometimes cause the second stage table to be slightly longer than the first stage, which makes the build inconsistent. Add it to the exception table that contains all other kallsyms-generated symbols. Fixes: 60443c88f3a8 ("kallsyms: Improve the performance of kallsyms_lookup_name()") Signed-off-by: Arnd Bergmann <arnd@arndb.de> Reviewed-by: Zhen Lei <thunder.leizhen@huawei.com> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2022-12-16Merge tag 'char-misc-6.2-rc1' of ↵Linus Torvalds1-1/+2
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc Pull char/misc driver updates from Greg KH: "Here is the large set of char/misc and other driver subsystem changes for 6.2-rc1. Nothing earth-shattering in here at all, just a lot of new driver development and minor fixes. Highlights include: - fastrpc driver updates - iio new drivers and updates - habanalabs driver updates for new hardware and features - slimbus driver updates - speakup module parameters added to aid in boot time configuration - i2c probe_new conversions for lots of different drivers - other small driver fixes and additions One semi-interesting change in here is the increase of the number of misc dynamic minors available to 1048448 to handle new huge-cpu systems. All of these have been in linux-next for a while with no reported problems" * tag 'char-misc-6.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (521 commits) extcon: usbc-tusb320: Convert to i2c's .probe_new() extcon: rt8973: Convert to i2c's .probe_new() extcon: fsa9480: Convert to i2c's .probe_new() extcon: max77843: Replace irqchip mask_invert with unmask_base chardev: fix error handling in cdev_device_add() mcb: mcb-parse: fix error handing in chameleon_parse_gdd() drivers: mcb: fix resource leak in mcb_probe() coresight: etm4x: fix repeated words in comments coresight: cti: Fix null pointer error on CTI init before ETM coresight: trbe: remove cpuhp instance node before remove cpuhp state counter: stm32-lptimer-cnt: fix the check on arr and cmp registers update misc: fastrpc: Add dma_mask to fastrpc_channel_ctx misc: fastrpc: Add mmap request assigning for static PD pool misc: fastrpc: Safekeep mmaps on interrupted invoke misc: fastrpc: Add support for audiopd misc: fastrpc: Rework fastrpc_req_munmap misc: fastrpc: Use fastrpc_map_put in fastrpc_map_create on fail misc: fastrpc: Add fastrpc_remote_heap_alloc misc: fastrpc: Add reserved mem support misc: fastrpc: Rename audio protection domain to root ...
2022-11-23scripts/kallsyms.c Make the comment up-to-date with current implementationYuma Ueda1-1/+2
The comment in scripts/kallsyms.c describing the usage of scripts/kallsyms does not reflect the latest implementation. Fix the comment to be equivalent to what the usage() function prints. Signed-off-by: Yuma Ueda <cyan@0x00a1e9.dev> Reviewed-by: Miguel Ojeda <ojeda@kernel.org> Link: https://lore.kernel.org/r/20221118133631.4554-1-cyan@0x00a1e9.dev Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-11-13kallsyms: Reduce the memory occupied by kallsyms_seqs_of_names[]Zhen Lei1-1/+4
kallsyms_seqs_of_names[] records the symbol index sorted by address, the maximum value in kallsyms_seqs_of_names[] is the number of symbols. And 2^24 = 16777216, which means that three bytes are enough to store the index. This can help us save (1 * kallsyms_num_syms) bytes of memory. Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com> Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
2022-11-13kallsyms: Correctly sequence symbols when CONFIG_LTO_CLANG=yZhen Lei1-2/+34
LLVM appends various suffixes for local functions and variables, suffixes observed: - foo.llvm.[0-9a-f]+ - foo.[0-9a-f]+ Therefore, when CONFIG_LTO_CLANG=y, kallsyms_lookup_name() needs to truncate the suffix of the symbol name before comparing the local function or variable name. Old implementation code: - if (strcmp(namebuf, name) == 0) - return kallsyms_sym_address(i); - if (cleanup_symbol_name(namebuf) && strcmp(namebuf, name) == 0) - return kallsyms_sym_address(i); The preceding process is traversed by address from low to high. That is, for those with the same name after the suffix is removed, the one with the smallest address is returned first. Therefore, when sorting in the tool, if the raw names are the same, they should be sorted by address in ascending order. ASCII[.] = 2e ASCII[0-9] = 30,39 ASCII[A-Z] = 41,5a ASCII[_] = 5f ASCII[a-z] = 61,7a According to the preceding ASCII code values, the following sorting result is strictly followed. --------------------------------- | main-key | sub-key | |---------------------------------| | | addr_lowest | | <name> | ... | | <name>.<suffix> | ... | | | addr_highest | |---------------------------------| | <name>?<others> | | //? is [_A-Za-z0-9] --------------------------------- Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com> Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
2022-11-13kallsyms: Improve the performance of kallsyms_lookup_name()Zhen Lei1-0/+37
Currently, to search for a symbol, we need to expand the symbols in 'kallsyms_names' one by one, and then use the expanded string for comparison. It's O(n). If we sort names in ascending order like addresses, we can also use binary search. It's O(log(n)). In order not to change the implementation of "/proc/kallsyms", the table kallsyms_names[] is still stored in a one-to-one correspondence with the address in ascending order. Add array kallsyms_seqs_of_names[], it's indexed by the sequence number of the sorted names, and the corresponding content is the sequence number of the sorted addresses. For example: Assume that the index of NameX in array kallsyms_seqs_of_names[] is 'i', the content of kallsyms_seqs_of_names[i] is 'k', then the corresponding address of NameX is kallsyms_addresses[k]. The offset in kallsyms_names[] is get_symbol_offset(k). Note that the memory usage will increase by (4 * kallsyms_num_syms) bytes, the next two patches will reduce (1 * kallsyms_num_syms) bytes and properly handle the case CONFIG_LTO_CLANG=y. Performance test results: (x86) Before: min=234, max=10364402, avg=5206926 min=267, max=11168517, avg=5207587 After: min=1016, max=90894, avg=7272 min=1014, max=93470, avg=7293 The average lookup performance of kallsyms_lookup_name() improved 715x. Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com> Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
2022-11-13scripts/kallsyms: rename build_initial_tok_table()Zhen Lei1-2/+2
Except for the function build_initial_tok_table(), no token abbreviation is used elsewhere. $ cat scripts/kallsyms.c | grep tok | wc -l 33 $ cat scripts/kallsyms.c | grep token | wc -l 31 Here, it would be clearer to use the full name. Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com> Reviewed-by: Petr Mladek <pmladek@suse.com> Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
2022-10-10Merge tag 'kbuild-v6.1' of ↵Linus Torvalds1-21/+33
git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild Pull Kbuild updates from Masahiro Yamada: - Remove potentially incomplete targets when Kbuid is interrupted by SIGINT etc in case GNU Make may miss to do that when stderr is piped to another program. - Rewrite the single target build so it works more correctly. - Fix rpm-pkg builds with V=1. - List top-level subdirectories in ./Kbuild. - Ignore auto-generated __kstrtab_* and __kstrtabns_* symbols in kallsyms. - Avoid two different modules in lib/zstd/ having shared code, which potentially causes building the common code as build-in and modular back-and-forth. - Unify two modpost invocations to optimize the build process. - Remove head-y syntax in favor of linker scripts for placing particular sections in the head of vmlinux. - Bump the minimal GNU Make version to 3.82. - Clean up misc Makefiles and scripts. * tag 'kbuild-v6.1' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (41 commits) docs: bump minimal GNU Make version to 3.82 ia64: simplify esi object addition in Makefile Revert "kbuild: Check if linker supports the -X option" kbuild: rebuild .vmlinux.export.o when its prerequisite is updated kbuild: move modules.builtin(.modinfo) rules to Makefile.vmlinux_o zstd: Fixing mixed module-builtin objects kallsyms: ignore __kstrtab_* and __kstrtabns_* symbols kallsyms: take the input file instead of reading stdin kallsyms: drop duplicated ignore patterns from kallsyms.c kbuild: reuse mksysmap output for kallsyms mksysmap: update comment about __crc_* kbuild: remove head-y syntax kbuild: use obj-y instead extra-y for objects placed at the head kbuild: hide error checker logs for V=1 builds kbuild: re-run modpost when it is updated kbuild: unify two modpost invocations kbuild: move vmlinux.o rule to the top Makefile kbuild: move .vmlinux.objs rule to Makefile.modpost kbuild: list sub-directories in ./Kbuild Makefile.compiler: replace cc-ifversion with compiler-specific macros ...
2022-10-04Merge tag 'kcfi-v6.1-rc1' of ↵Linus Torvalds1-0/+1
git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux Pull kcfi updates from Kees Cook: "This replaces the prior support for Clang's standard Control Flow Integrity (CFI) instrumentation, which has required a lot of special conditions (e.g. LTO) and work-arounds. The new implementation ("Kernel CFI") is specific to C, directly designed for the Linux kernel, and takes advantage of architectural features like x86's IBT. This series retains arm64 support and adds x86 support. GCC support is expected in the future[1], and additional "generic" architectural support is expected soon[2]. Summary: - treewide: Remove old CFI support details - arm64: Replace Clang CFI support with Clang KCFI support - x86: Introduce Clang KCFI support" Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107048 [1] Link: https://github.com/samitolvanen/llvm-project/commits/kcfi_generic [2] * tag 'kcfi-v6.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: (22 commits) x86: Add support for CONFIG_CFI_CLANG x86/purgatory: Disable CFI x86: Add types to indirectly called assembly functions x86/tools/relocs: Ignore __kcfi_typeid_ relocations kallsyms: Drop CONFIG_CFI_CLANG workarounds objtool: Disable CFI warnings objtool: Preserve special st_shndx indexes in elf_update_symbol treewide: Drop __cficanonical treewide: Drop WARN_ON_FUNCTION_MISMATCH treewide: Drop function_nocfi init: Drop __nocfi from __init arm64: Drop unneeded __nocfi attributes arm64: Add CFI error handling arm64: Add types to indirect called assembly functions psci: Fix the function type for psci_initcall_t lkdtm: Emit an indirect call for CFI tests cfi: Add type helper macros cfi: Switch to -fsanitize=kcfi cfi: Drop __CFI_ADDRESSABLE cfi: Remove CONFIG_CFI_CLANG_SHADOW ...
2022-10-02kallsyms: take the input file instead of reading stdinMasahiro Yamada1-18/+33
This gets rid of the pipe operator connected with 'cat'. Also use getopt_long() to parse the command line. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2022-10-02kallsyms: drop duplicated ignore patterns from kallsyms.cMasahiro Yamada1-3/+0
Now that kallsyms.c parses the output from mksysmap, some symbols have already been dropped. Move comments to scripts/mksysmap. Also, make the grep command readable. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2022-09-28kallsyms: increase maximum kernel symbol length to 512Miguel Ojeda1-2/+2
Rust symbols can become quite long due to namespacing introduced by modules, types, traits, generics, etc. For instance, the following code: pub mod my_module { pub struct MyType; pub struct MyGenericType<T>(T); pub trait MyTrait { fn my_method() -> u32; } impl MyTrait for MyGenericType<MyType> { fn my_method() -> u32 { 42 } } } generates a symbol of length 96 when using the upcoming v0 mangling scheme: _RNvXNtCshGpAVYOtgW1_7example9my_moduleINtB2_13MyGenericTypeNtB2_6MyTypeENtB2_7MyTrait9my_method At the moment, Rust symbols may reach up to 300 in length. Setting 512 as the maximum seems like a reasonable choice to keep some headroom. Reviewed-by: Kees Cook <keescook@chromium.org> Reviewed-by: Petr Mladek <pmladek@suse.com> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Co-developed-by: Alex Gaynor <alex.gaynor@gmail.com> Signed-off-by: Alex Gaynor <alex.gaynor@gmail.com> Co-developed-by: Wedson Almeida Filho <wedsonaf@google.com> Signed-off-by: Wedson Almeida Filho <wedsonaf@google.com> Co-developed-by: Gary Guo <gary@garyguo.net> Signed-off-by: Gary Guo <gary@garyguo.net> Co-developed-by: Boqun Feng <boqun.feng@gmail.com> Signed-off-by: Boqun Feng <boqun.feng@gmail.com> Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2022-09-28kallsyms: support "big" kernel symbolsMiguel Ojeda1-3/+26
Rust symbols can become quite long due to namespacing introduced by modules, types, traits, generics, etc. Increasing to 255 is not enough in some cases, therefore introduce longer lengths to the symbol table. In order to avoid increasing all lengths to 2 bytes (since most of them are small, including many Rust ones), use ULEB128 to keep smaller symbols in 1 byte, with the rest in 2 bytes. Reviewed-by: Kees Cook <keescook@chromium.org> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Co-developed-by: Alex Gaynor <alex.gaynor@gmail.com> Signed-off-by: Alex Gaynor <alex.gaynor@gmail.com> Co-developed-by: Wedson Almeida Filho <wedsonaf@google.com> Signed-off-by: Wedson Almeida Filho <wedsonaf@google.com> Co-developed-by: Gary Guo <gary@garyguo.net> Signed-off-by: Gary Guo <gary@garyguo.net> Co-developed-by: Boqun Feng <boqun.feng@gmail.com> Signed-off-by: Boqun Feng <boqun.feng@gmail.com> Co-developed-by: Matthew Wilcox <willy@infradead.org> Signed-off-by: Matthew Wilcox <willy@infradead.org> Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2022-09-28kallsyms: add static relationship between `KSYM_NAME_LEN{,_BUFFER}`Miguel Ojeda1-2/+12
This adds a static assert to ensure `KSYM_NAME_LEN_BUFFER` gets updated when `KSYM_NAME_LEN` changes. The relationship used is one that keeps the new size (512+1) close to the original buffer size (500). Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Co-developed-by: Boqun Feng <boqun.feng@gmail.com> Signed-off-by: Boqun Feng <boqun.feng@gmail.com> Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2022-09-28kallsyms: avoid hardcoding buffer sizeBoqun Feng1-2/+8
This introduces `KSYM_NAME_LEN_BUFFER` in place of the previously hardcoded size of the input buffer. It will also make it easier to update the size in a single place in a later patch. Reviewed-by: Kees Cook <keescook@chromium.org> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Boqun Feng <boqun.feng@gmail.com> Co-developed-by: Miguel Ojeda <ojeda@kernel.org> Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2022-09-28kallsyms: use `ARRAY_SIZE` instead of hardcoded sizeBoqun Feng1-1/+1
This removes one place where the `500` constant is hardcoded. Reviewed-by: Kees Cook <keescook@chromium.org> Reviewed-by: Geert Stappers <stappers@stappers.nl> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Boqun Feng <boqun.feng@gmail.com> Co-developed-by: Miguel Ojeda <ojeda@kernel.org> Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2022-09-26scripts/kallsyms: Ignore __kcfi_typeid_Sami Tolvanen1-0/+1
The compiler generates __kcfi_typeid_ symbols for annotating assembly functions with type information. These are constants that can be referenced in assembly code and are resolved by the linker. Ignore them in kallsyms. Signed-off-by: Sami Tolvanen <samitolvanen@google.com> Reviewed-by: Kees Cook <keescook@chromium.org> Tested-by: Kees Cook <keescook@chromium.org> Tested-by: Nathan Chancellor <nathan@kernel.org> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Tested-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/20220908215504.3686827-3-samitolvanen@google.com
2022-05-27scripts/kallsyms: update usage message of the kallsyms programYuntao Wang1-1/+1
The kallsyms program supports --absolute-percpu option but does not display it in the usage message, fix it. Signed-off-by: Yuntao Wang <ytcoode@gmail.com> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2022-04-28KVM: arm64: Symbolize the nVHE HYP addressesKalesh Singh1-1/+2
Reintroduce the __kvm_nvhe_ symbols in kallsyms, ignoring the local symbols in this namespace. The local symbols are not informative and can cause aliasing issues when symbolizing the addresses. With the necessary symbols now in kallsyms we can symbolize nVHE addresses using the %p print format specifier: [ 98.916444][ T426] kvm [426]: nVHE hyp panic at: [<ffffffc0096156fc>] __kvm_nvhe_overflow_stack+0x8/0x34! Signed-off-by: Kalesh Singh <kaleshsingh@google.com> Tested-by: Fuad Tabba <tabba@google.com> Reviewed-by: Fuad Tabba <tabba@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20220420214317.3303360-7-kaleshsingh@google.com
2022-02-21kallsyms: ignore all local labels prefixed by '.L'Changbin Du1-1/+1
The llvm compiler can generate lots of local labels ('.LBB', '.Ltmpxxx', '.L__unnamed_xx', etc.). These symbols usually are useless for debugging. And they might overlap with handwritten symbols. Before this change, a dumpstack shows a local symbol for epc: [ 0.040341][ T0] Hardware name: riscv-virtio,qemu (DT) [ 0.040376][ T0] epc : .LBB6_14+0x22/0x6a [ 0.040452][ T0] ra : restore_all+0x12/0x6e The simple solution is that we can ignore all local labels prefixed by '.L'. For handwritten symbols which need to be preserved should drop the '.L' prefix. After this change, the C defined symbol is shown so we can locate the problematical code immediately: [ 0.035795][ T0] Hardware name: riscv-virtio,qemu (DT) [ 0.036332][ T0] epc : trace_hardirqs_on+0x54/0x13c [ 0.036567][ T0] ra : restore_all+0x12/0x6e Signed-off-by: Changbin Du <changbin.du@gmail.com> Reviewed-by: Nathan Chancellor <nathan@kernel.org> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2021-02-05kallsyms: fix nonconverging kallsyms table with lldArnd Bergmann1-0/+6
ARM randconfig builds with lld sometimes show a build failure from kallsyms: Inconsistent kallsyms data Try make KALLSYMS_EXTRA_PASS=1 as a workaround The problem is the veneers/thunks getting added by the linker extend the symbol table, which in turn leads to more veneers being needed, so it may take a few extra iterations to converge. This bug has been fixed multiple times before, but comes back every time a new symbol name is used. lld uses a different set of identifiers from ld.bfd, so the additional ones need to be added as well. I looked through the sources and found that arm64 and mips define similar prefixes, so I'm adding those as well, aside from the ones I observed. I'm not sure about powerpc64, which seems to already be handled through a section match, but if it comes back, the "__long_branch_" and "__plt_" prefixes would have to get added as well. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-09-24scripts/kallsyms: skip ppc compiler stub *.long_branch.* / *.plt_branch.*Masahiro Yamada1-1/+15
PowerPC allmodconfig often fails to build as follows: LD .tmp_vmlinux.kallsyms1 KSYM .tmp_vmlinux.kallsyms1.o LD .tmp_vmlinux.kallsyms2 KSYM .tmp_vmlinux.kallsyms2.o LD .tmp_vmlinux.kallsyms3 KSYM .tmp_vmlinux.kallsyms3.o LD vmlinux SORTTAB vmlinux SYSMAP System.map Inconsistent kallsyms data Try make KALLSYMS_EXTRA_PASS=1 as a workaround make[2]: *** [../Makefile:1162: vmlinux] Error 1 Setting KALLSYMS_EXTRA_PASS=1 does not help. This is caused by the compiler inserting stubs such as *.long_branch.* and *.plt_branch.* $ powerpc-linux-nm -n .tmp_vmlinux.kallsyms2 [ snip ] c00000000210c010 t 00000075.plt_branch.da9:19 c00000000210c020 t 00000075.plt_branch.1677:5 c00000000210c030 t 00000075.long_branch.memmove c00000000210c034 t 00000075.plt_branch.9e0:5 c00000000210c044 t 00000075.plt_branch.free_initrd_mem ... Actually, the problem mentioned in scripts/link-vmlinux.sh comments; "In theory it's possible this results in even more stubs, but unlikely" is happening here, and ends up with another kallsyms step required. scripts/kallsyms.c already ignores various compiler stubs. Let's do similar to make kallsysms for PowerPC always succeed in 2 steps. Reported-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Tested-by: Guenter Roeck <linux@roeck-us.net>
2020-07-05KVM: arm64: Add build rules for separate VHE/nVHE object filesDavid Brazdil1-0/+1
Add new folders arch/arm64/kvm/hyp/{vhe,nvhe} and Makefiles for building code that runs in EL2 under VHE/nVHE KVM, repsectivelly. Add an include folder for hyp-specific header files which will include code common to VHE/nVHE. Build nVHE code with -D__KVM_NVHE_HYPERVISOR__, VHE code with -D__KVM_VHE_HYPERVISOR__. Under nVHE compile each source file into a `.hyp.tmp.o` object first, then prefix all its symbols with "__kvm_nvhe_" using `objcopy` and produce a `.hyp.o`. Suffixes were chosen so that it would be possible for VHE and nVHE to share some source files, but compiled with different CFLAGS. The nVHE ELF symbol prefix is added to kallsyms.c as ignored. EL2-only symbols will never appear in EL1 stack traces. Due to symbol prefixing, add a section in image-vars.h for aliases of symbols that are defined in nVHE EL2 and accessed by kernel in EL1 or vice versa. Signed-off-by: David Brazdil <dbrazdil@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20200625131420.71444-4-dbrazdil@google.com
2020-05-04gcc-10 warnings: fix low-hanging fruitLinus Torvalds1-1/+1
Due to a bug-report that was compiler-dependent, I updated one of my machines to gcc-10. That shows a lot of new warnings. Happily they seem to be mostly the valid kind, but it's going to cause a round of churn for getting rid of them.. This is the really low-hanging fruit of removing a couple of zero-sized arrays in some core code. We have had a round of these patches before, and we'll have many more coming, and there is nothing special about these except that they were particularly trivial, and triggered more warnings than most. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-03-19scripts/kallsyms: fix wrong kallsyms_relative_baseMikhail Petrov1-4/+4
There is the code in the read_symbol function in 'scripts/kallsyms.c': if (is_ignored_symbol(name, type)) return NULL; /* Ignore most absolute/undefined (?) symbols. */ if (strcmp(name, "_text") == 0) _text = addr; But the is_ignored_symbol function returns true for name="_text" and type='A'. So the next condition is not executed and the _text variable is always zero. It makes the wrong kallsyms_relative_base symbol as a result of the code (CONFIG_KALLSYMS_BASE_RELATIVE is defined): if (base_relative) { output_label("kallsyms_relative_base"); output_address(relative_base); printf("\n"); } Because the output_address function uses the _text variable. So the kallsyms_lookup function and all related functions in the kernel do not work properly. For example, the stack trace in oops: Call Trace: [aa095e58] [809feab8] kobj_ns_ops_tbl+0x7ff09ac8/0x7ff1c1c4 (unreliable) [aa095e98] [80002b64] kobj_ns_ops_tbl+0x7f50db74/0x80000010 [aa095ef8] [809c3d24] kobj_ns_ops_tbl+0x7feced34/0x7ff1c1c4 [aa095f28] [80002ed0] kobj_ns_ops_tbl+0x7f50dee0/0x80000010 [aa095f38] [8000f238] kobj_ns_ops_tbl+0x7f51a248/0x80000010 The right stack trace: Call Trace: [aa095e58] [809feab8] module_vdu_video_init+0x2fc/0x3bc (unreliable) [aa095e98] [80002b64] do_one_initcall+0x40/0x1f0 [aa095ef8] [809c3d24] kernel_init_freeable+0x164/0x1d8 [aa095f28] [80002ed0] kernel_init+0x14/0x124 [aa095f38] [8000f238] ret_from_kernel_thread+0x14/0x1c [masahiroy@kernel.org: This issue happens on binutils <= 2.22 The following commit fixed it: https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=d2667025dd30611514810c28bee9709e4623012a The symbol type of _text is 'T' on binutils >= 2.23 The minimal supported binutils version for the kernel build is 2.21 ] Signed-off-by: Mikhail Petrov <Mikhail.Petrov@mir.dev> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-02-10scripts/kallsyms: fix memory corruption caused by write over-runMasahiro Yamada1-2/+2
memcpy() writes one more byte than allocated. Fixes: 8d60526999aa ("scripts/kallsyms: change table to store (strcut sym_entry *)") Reported-by: youling257 <youling257@gmail.com> Reported-by: Pavel Machek <pavel@ucw.cz> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Tested-by: Pavel Machek <pavel@ucw.cz>
2020-02-03scripts/kallsyms: change table to store (strcut sym_entry *)Masahiro Yamada1-56/+65
The symbol table is extended every 10000 addition by using realloc(), where data copy might occur to the new buffer. To decrease the amount of possible data copy, let's change the table to store the pointer. The symbol type + symbol name part is appended at the end of (struct sym_entry), and allocated together with the struct body. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-02-03scripts/kallsyms: rename local variables in read_symbol()Masahiro Yamada1-12/+12
I will use 'sym' for the point to struce sym_entry in the next commit. Rename 'sym', 'stype' to 'name', 'type', which are more intuitive. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2019-12-14scripts/kallsyms: fix offset overflow of kallsyms_relative_baseMasahiro Yamada1-20/+18
Since commit 5e5c4fa78745 ("scripts/kallsyms: shrink table before sorting it"), kallsyms_relative_base can be larger than _text, which causes overflow when building the 32-bit kernel. https://lkml.org/lkml/2019/12/7/156 This is because _text is, unless --all-symbols is specified, now trimmed from the symbol table before record_relative_base() is called. Handle the offset signedness also for kallsyms_relative_base. Introduce a new helper, output_address(), to reduce the code duplication. Fixes: 5e5c4fa78745 ("scripts/kallsyms: shrink table before sorting it") Reported-by: Olof Johansson <olof@lixom.net> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2019-11-25scripts/kallsyms: remove redundant initializersMasahiro Yamada1-3/+3
These are set to zero without the explicit initializers. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2019-11-25scripts/kallsyms: put check_symbol_range() calls close togetherMasahiro Yamada1-3/+1
Put the relevant code close together. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2019-11-25scripts/kallsyms: make check_symbol_range() void functionMasahiro Yamada1-9/+6
There is no more reason to check the return value of check_symbol_range(). Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2019-11-25scripts/kallsyms: move ignored symbol types to is_ignored_symbol()Masahiro Yamada1-15/+15
Collect the ignored patterns to is_ignored_symbol(). Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2019-11-25scripts/kallsyms: move more patterns to the ignored_prefixes arrayMasahiro Yamada1-10/+2
Refactoring for shortening the code. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2019-11-25scripts/kallsyms: skip ignored symbols very earlyMasahiro Yamada1-51/+62
Unless the address range matters, symbols can be ignored earlier, which avoids unneeded memory allocation. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2019-11-25scripts/kallsyms: add const qualifiers where possibleMasahiro Yamada1-14/+14
Add 'const' where a function does not write to the pointer dereferenes. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2019-11-25scripts/kallsyms: make find_token() return (unsigned char *)Masahiro Yamada1-1/+2
The callers of this function expect (unsigned char *). I do not see a good reason to make this function return (void *). Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2019-11-25scripts/kallsyms: replace prefix_underscores_count() with strspn()Masahiro Yamada1-12/+2
You can do equivalent things with strspn(). I do not see noticeable performance difference. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2019-11-25scripts/kallsyms: add sym_name() to mitigate cast uglinessMasahiro Yamada1-13/+16
sym_entry::sym is (unsigned char *) instead of (char *) because kallsyms exploits the MSB for compression, and the characters are used as the index of token_profit array. However, it requires casting (unsigned char *) to (char *) in some places since standard library functions such as strcmp(), strlen() expect (char *). Introduce a new helper, sym_name(), which advances the given pointer by 1 and casts it to (char *). Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
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