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2019-07-08kallsyms: exclude kasan local symbols on s390Vasily Gorbik1-0/+3
gcc asan instrumentation emits the following sequence to store frame pc when the kernel is built with CONFIG_RELOCATABLE: debug/vsprintf.s: .section .data.rel.ro.local,"aw" .align 8 .LC3: .quad .LASANPC4826@GOTOFF .text .align 8 .type number, @function number: .LASANPC4826: and in case reloc is issued for LASANPC label it also gets into .symtab with the same address as actual function symbol: $ nm -n vmlinux | grep 0000000001397150 0000000001397150 t .LASANPC4826 0000000001397150 t number In the end kernel backtraces are almost unreadable: [ 143.748476] Call Trace: [ 143.748484] ([<000000002da3e62c>] .LASANPC2671+0x114/0x190) [ 143.748492] [<000000002eca1a58>] .LASANPC2612+0x110/0x160 [ 143.748502] [<000000002de9d830>] print_address_description+0x80/0x3b0 [ 143.748511] [<000000002de9dd64>] __kasan_report+0x15c/0x1c8 [ 143.748521] [<000000002ecb56d4>] strrchr+0x34/0x60 [ 143.748534] [<000003ff800a9a40>] kasan_strings+0xb0/0x148 [test_kasan] [ 143.748547] [<000003ff800a9bba>] kmalloc_tests_init+0xe2/0x528 [test_kasan] [ 143.748555] [<000000002da2117c>] .LASANPC4069+0x354/0x748 [ 143.748563] [<000000002dbfbb16>] do_init_module+0x136/0x3b0 [ 143.748571] [<000000002dbff3f4>] .LASANPC3191+0x2164/0x25d0 [ 143.748580] [<000000002dbffc4c>] .LASANPC3196+0x184/0x1b8 [ 143.748587] [<000000002ecdf2ec>] system_call+0xd8/0x2d8 Since LASANPC labels are not even unique and get into .symtab only due to relocs filter them out in kallsyms. Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2019-03-10Merge tag 'kbuild-v5.1' of ↵Linus Torvalds1-8/+5
git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild Pull Kbuild updates from Masahiro Yamada: - do not generate unneeded top-level built-in.a - let git ignore O= directory entirely - optimize scripts/kallsyms slightly - exclude DWARF info from *.s regardless of config options - fix GCC toolchain search path for Clang to prepare ld.lld support - do not generate modules.order when CONFIG_MODULES is disabled - simplify single target rules and remove VPATH for external module build - allow to add optional flags to dpkg-buildpackage when building deb-pkg - move some compiler option tests from Makefile to Kconfig - various Makefile cleanups * tag 'kbuild-v5.1' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (40 commits) kbuild: remove scripts/basic/% build target kbuild: use -Werror=implicit-... instead of -Werror-implicit-... kbuild: clean up scripts/gcc-version.sh kbuild: remove cc-version macro kbuild: update comment block of scripts/clang-version.sh kbuild: remove commented-out INITRD_COMPRESS kbuild: move -gsplit-dwarf, -gdwarf-4 option tests to Kconfig kbuild: [bin]deb-pkg: add DPKG_FLAGS variable kbuild: move ".config not found!" message from Kconfig to Makefile kbuild: invoke syncconfig if include/config/auto.conf.cmd is missing kbuild: simplify single target rules kbuild: remove empty rules for makefiles kbuild: make -r/-R effective in top Makefile for old Make versions kbuild: move tools_silent to a more relevant place kbuild: compute false-positive -Wmaybe-uninitialized cases in Kconfig kbuild: refactor cc-cross-prefix implementation kbuild: hardcode genksyms path and remove GENKSYMS variable scripts/gdb: refactor rules for symlink creation kbuild: create symlink to vmlinux-gdb.py in scripts_gdb target scripts/gdb: do not descend into scripts/gdb from scripts ...
2019-02-19kallsyms: include <asm/bitsperlong.h> instead of <asm/types.h>Masahiro Yamada1-1/+1
<asm/bitsperlong.h> is enough to include the definition of BITS_PER_LONG. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2019-02-19kallsyms: remove unneeded memset() callsMasahiro Yamada1-3/+0
Global variables in the .bss section are zeroed out before the program starts to run. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2019-02-19kallsyms: add static qualifiers where missingMasahiro Yamada1-4/+4
Fix the following sparse warnings: scripts/kallsyms.c:65:5: warning: symbol 'token_profit' was not declared. Should it be static? scripts/kallsyms.c:68:15: warning: symbol 'best_table' was not declared. Should it be static? scripts/kallsyms.c:69:15: warning: symbol 'best_table_len' was not declared. Should it be static? Also, remove 'inline' from is_arm_mapping_symbol(). The compiler will inline it anyway when it is appropriate to do so. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2019-01-28kallsyms: Handle too long symbols in kallsyms.cEugene Loh1-2/+2
When checking for symbols with excessively long names, account for null terminating character. Fixes: f3462aa952cf ("Kbuild: Handle longer symbols in kallsyms.c") Signed-off-by: Eugene Loh <eugene.loh@oracle.com> Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2019-01-06kallsyms: lower alignment on ARMMathias Krause1-2/+2
As mentioned in the info pages of gas, the '.align' pseudo op's interpretation of the alignment value is architecture specific. It might either be a byte value or taken to the power of two. On ARM it's actually the latter which leads to unnecessary large alignments of 16 bytes for 32 bit builds or 256 bytes for 64 bit builds. Fix this by switching to '.balign' instead which is consistent across all architectures. Signed-off-by: Mathias Krause <minipli@googlemail.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-09-10kallsyms: remove left-over Blackfin codeMasahiro Yamada1-2/+0
These symbols were added by commit 028f042613c3 ("kallsyms: support kernel symbols in Blackfin on-chip memory") for Blackfin. The Blackfin support was removed by commit 4ba66a976072 ("arch: remove blackfin port"). Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-09-10kallsyms: reduce size a little on 64-bitJan Beulich1-2/+2
Both kallsyms_num_syms and kallsyms_markers[] don't really need to use unsigned long as their (base) types; unsigned int fully suffices. Signed-off-by: Jan Beulich <jbeulich@suse.com> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-05-29scripts: Fixed printf format mismatchnixiaoming1-1/+1
scripts/kallsyms.c: function write_src: "printf", the #1 format specifier "d" need arg type "int", but the according arg "table_cnt" has type "unsigned int" scripts/recordmcount.c: function do_file: "fprintf", the #1 format specifier "d" need arg type "int", but the according arg "(*w2)(ehdr->e_machine)" has type "unsigned int" scripts/recordmcount.h: function find_secsym_ndx: "fprintf", the #1 format specifier "d" need arg type "int", but the according arg "txtndx" has type "unsigned int" Signed-off-by: nixiaoming <nixiaoming@huawei.com> Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-05-17kallsyms: remove symbol prefix supportMasahiro Yamada1-36/+11
CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX was selected by BLACKFIN, METAG. They were removed by commit 4ba66a976072 ("arch: remove blackfin port"), commit bb6fb6dfcc17 ("metag: Remove arch/metag/"), respectively. No more architecture enables CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX, hence the --symbol-prefix option is unnecessary. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
2018-04-04Merge tag 'arm64-upstream' of ↵Linus Torvalds1-0/+1
git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux Pull arm64 updates from Will Deacon: "Nothing particularly stands out here, probably because people were tied up with spectre/meltdown stuff last time around. Still, the main pieces are: - Rework of our CPU features framework so that we can whitelist CPUs that don't require kpti even in a heterogeneous system - Support for the IDC/DIC architecture extensions, which allow us to elide instruction and data cache maintenance when writing out instructions - Removal of the large memory model which resulted in suboptimal codegen by the compiler and increased the use of literal pools, which could potentially be used as ROP gadgets since they are mapped as executable - Rework of forced signal delivery so that the siginfo_t is well-formed and handling of show_unhandled_signals is consolidated and made consistent between different fault types - More siginfo cleanup based on the initial patches from Eric Biederman - Workaround for Cortex-A55 erratum #1024718 - Some small ACPI IORT updates and cleanups from Lorenzo Pieralisi - Misc cleanups and non-critical fixes" * tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (70 commits) arm64: uaccess: Fix omissions from usercopy whitelist arm64: fpsimd: Split cpu field out from struct fpsimd_state arm64: tlbflush: avoid writing RES0 bits arm64: cmpxchg: Include linux/compiler.h in asm/cmpxchg.h arm64: move percpu cmpxchg implementation from cmpxchg.h to percpu.h arm64: cmpxchg: Include build_bug.h instead of bug.h for BUILD_BUG arm64: lse: Include compiler_types.h and export.h for out-of-line LL/SC arm64: fpsimd: include <linux/init.h> in fpsimd.h drivers/perf: arm_pmu_platform: do not warn about affinity on uniprocessor perf: arm_spe: include linux/vmalloc.h for vmap() Revert "arm64: Revert L1_CACHE_SHIFT back to 6 (64-byte cache line size)" arm64: cpufeature: Avoid warnings due to unused symbols arm64: Add work around for Arm Cortex-A55 Erratum 1024718 arm64: Delay enabling hardware DBM feature arm64: Add MIDR encoding for Arm Cortex-A55 and Cortex-A35 arm64: capabilities: Handle shared entries arm64: capabilities: Add support for checks based on a list of MIDRs arm64: Add helpers for checking CPU MIDR against a range arm64: capabilities: Clean up midr range helpers arm64: capabilities: Change scope of VHE to Boot CPU feature ...
2018-03-06scripts/kallsyms: filter arm64's __efistub_ symbolsArd Biesheuvel1-0/+1
On arm64, the EFI stub and the kernel proper are essentially the same binary, although the EFI stub executes at a different virtual address as the kernel. For this reason, the EFI stub is restricted in the symbols it can link to, which is ensured by prefixing all EFI stub symbols with __efistub_ (and emitting __efistub_ prefixed aliases for routines that may be shared between the core kernel and the stub) These symbols are leaking into kallsyms, polluting the namespace, so let's filter them explicitly. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-03-02kbuild/kallsyms: trivial typo fixCao jin1-1/+1
Signed-off-by: Cao jin <caoj.fnst@cn.fujitsu.com> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2017-10-13scripts/kallsyms.c: ignore symbol type 'n'Guenter Roeck1-1/+1
gcc on aarch64 may emit synbols of type 'n' if the kernel is built with '-frecord-gcc-switches'. In most cases, those symbols are reported with nm as 000000000000000e n $d and with objdump as 0000000000000000 l d .GCC.command.line 0000000000000000 .GCC.command.line 000000000000000e l .GCC.command.line 0000000000000000 $d Those symbols are detected in is_arm_mapping_symbol() and ignored. However, if "--prefix-symbols=<prefix>" is configured as well, the situation is different. For example, in efi/libstub, arm64 images are built with '--prefix-alloc-sections=.init --prefix-symbols=__efistub_'. In combination with '-frecord-gcc-switches', the symbols are now reported by nm as: 000000000000000e n __efistub_$d and by objdump as: 0000000000000000 l d .GCC.command.line 0000000000000000 .GCC.command.line 000000000000000e l .GCC.command.line 0000000000000000 __efistub_$d Those symbols are no longer ignored and included in the base address calculation. This results in a base address of 000000000000000e, which in turn causes kallsyms to abort with kallsyms failure: relative symbol value 0xffffff900800a000 out of range in relative mode The problem is seen in little endian arm64 builds with CONFIG_EFI enabled and with '-frecord-gcc-switches' set in KCFLAGS. Explicitly ignore symbols of type 'n' since those are clearly debug symbols. Link: http://lkml.kernel.org/r/1507136063-3139-1-git-send-email-linux@roeck-us.net Signed-off-by: Guenter Roeck <linux@roeck-us.net> Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-02-03kbuild: modversions: add infrastructure for emitting relative CRCsArd Biesheuvel1-0/+12
This add the kbuild infrastructure that will allow architectures to emit vmlinux symbol CRCs as 32-bit offsets to another location in the kernel where the actual value is stored. This works around problems with CRCs being mistaken for relocatable symbols on kernels that self relocate at runtime (i.e., powerpc with CONFIG_RELOCATABLE=y) For the kbuild side of things, this comes down to the following: - introducing a Kconfig symbol MODULE_REL_CRCS - adding a -R switch to genksyms to instruct it to emit the CRC symbols as references into the .rodata section - making modpost distinguish such references from absolute CRC symbols by the section index (SHN_ABS) - making kallsyms disregard non-absolute symbols with a __crc_ prefix Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-12-11scripts/kallsyms: remove last remnants of --page-offset optionArd Biesheuvel1-1/+0
The implementation of the --page-offset kallsyms command line option has been removed, so remove it from the usage string as well. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Michal Marek <mmarek@suse.com>
2016-04-07ARM: 8553/1: kallsyms: remove --page-offset command line optionArd Biesheuvel1-8/+0
The --page-offset command line option was only used for ARM, to filter symbol addresses below CONFIG_PAGE_OFFSET. This is no longer needed, so remove the functionality altogether. Acked-by: Nicolas Pitre <nico@linaro.org> Acked-by: Chris Brandt <chris.brandt@renesas.com> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2016-04-07ARM: 8555/1: kallsyms: ignore ARM mode switching veneersArd Biesheuvel1-0/+2
On ARM, the linker may emit veneers to deal with relative branch instructions that appear too far away from their targets. Since the second kallsyms pass results in an increase of the kernel size, it may result in additional veneers to be emitted, potentially affecting the output of kallsyms itself if these symbols are visible to it, and for that reason, symbols whose names end in '_veneer' are ignored explicitly. However, when building Thumb2 kernels, such veneers are named differently if they also incur a mode switch, and since they are not filtered by kallsyms, they may cause the build to fail. So filter symbols whose names end in '_from_arm' or '_from_thumb' as well. Tested-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2016-03-15kallsyms: add support for relative offsets in kallsyms address tableArd Biesheuvel1-10/+69
Similar to how relative extables are implemented, it is possible to emit the kallsyms table in such a way that it contains offsets relative to some anchor point in the kernel image rather than absolute addresses. On 64-bit architectures, it cuts the size of the kallsyms address table in half, since offsets between kernel symbols can typically be expressed in 32 bits. This saves several hundreds of kilobytes of permanent .rodata on average. In addition, the kallsyms address table is no longer subject to dynamic relocation when CONFIG_RELOCATABLE is in effect, so the relocation work done after decompression now doesn't have to do relocation updates for all these values. This saves up to 24 bytes (i.e., the size of a ELF64 RELA relocation table entry) per value, which easily adds up to a couple of megabytes of uncompressed __init data on ppc64 or arm64. Even if these relocation entries typically compress well, the combined size reduction of 2.8 MB uncompressed for a ppc64_defconfig build (of which 2.4 MB is __init data) results in a ~500 KB space saving in the compressed image. Since it is useful for some architectures (like x86) to retain the ability to emit absolute values as well, this patch also adds support for capturing both absolute and relative values when KALLSYMS_ABSOLUTE_PERCPU is in effect, by emitting absolute per-cpu addresses as positive 32-bit values, and addresses relative to the lowest encountered relative symbol as negative values, which are subtracted from the runtime address of this base symbol to produce the actual address. Support for the above is enabled by default for all architectures except IA-64 and Tile-GX, whose symbols are too far apart to capture in this manner. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Tested-by: Guenter Roeck <linux@roeck-us.net> Reviewed-by: Kees Cook <keescook@chromium.org> Tested-by: Kees Cook <keescook@chromium.org> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Ingo Molnar <mingo@kernel.org> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Michal Marek <mmarek@suse.cz> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-03-15kallsyms: don't overload absolute symbol type for percpu symbolsArd Biesheuvel1-2/+12
Commit c6bda7c988a5 ("kallsyms: fix percpu vars on x86-64 with relocation") overloaded the 'A' (absolute) symbol type to signify that a symbol is not subject to dynamic relocation. However, the original A type does not imply that at all, and depending on the version of the toolchain, many A type symbols are emitted that are in fact relative to the kernel text, i.e., if the kernel is relocated at runtime, these symbols should be updated as well. For instance, on sparc32, the following symbols are emitted as absolute (kindly provided by Guenter Roeck): f035a420 A _etext f03d9000 A _sdata f03de8c4 A jiffies f03f8860 A _edata f03fc000 A __init_begin f041bdc8 A __init_text_end f0423000 A __bss_start f0423000 A __init_end f044457d A __bss_stop f044457d A _end On x86_64, similar behavior can be observed: ffffffff81a00000 A __end_rodata_hpage_align ffffffff81b19000 A __vvar_page ffffffff81d3d000 A _end Even if only a couple of them pass the symbol range check that results in them to be taken into account for the final kallsyms symbol table, it is obvious that 'A' does not mean the symbol does not need to be updated at relocation time, and overloading its meaning to signify that is perhaps not a good idea. So instead, add a new percpu_absolute member to struct sym_entry, and when --absolute-percpu is in effect, use it to record symbols whose addresses should be emitted as final values rather than values that still require relocation at runtime. That way, we can drop the check against the 'A' type. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Tested-by: Guenter Roeck <linux@roeck-us.net> Reviewed-by: Kees Cook <keescook@chromium.org> Tested-by: Kees Cook <keescook@chromium.org> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Ingo Molnar <mingo@kernel.org> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Michal Marek <mmarek@suse.cz> Acked-by: Rusty Russell <rusty@rustcorp.com.au> Cc: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-04-07Kbuild: kallsyms: drop special handling of pre-3.0 GCC symbolsArd Biesheuvel1-1/+0
Since we have required at least GCC v3.2 for some time now, we can drop the special handling of the 'gcc[0-9]_compiled.' label which is not emitted anymore since GCC v3.0. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Michal Marek <mmarek@suse.cz>
2015-04-07Kbuild: kallsyms: ignore veneers emitted by the ARM linkerArd Biesheuvel1-9/+21
When linking large kernels on ARM, the linker will insert veneers (i.e., PLT like stubs) when function symbols are out of reach for the ordinary relative branch/branch-and-link instructions. However, due to the fact that the kallsyms region sits in .rodata, which is between .text and .init.text, additional veneers may be emitted in the second pass due to the fact that the size of the kallsyms region itself has pushed the .init.text section further apart, requiring even more veneers. So ignore the veneers when generating the symbol table. Veneers have no corresponding source code, and they will not turn up in backtraces anyway. This patch also lightly refactors the symbol_valid() function to use a local 'sym_name' rather than the obfuscated 'sym + 1' and 'sym + offset' Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Michal Marek <mmarek@suse.cz>
2014-10-02aarch64: filter $x from kallsymsKyle McMartin1-1/+1
Similar to ARM, AArch64 is generating $x and $d syms... which isn't terribly helpful when looking at %pF output and the like. Filter those out in kallsyms, modpost and when looking at module symbols. Seems simplest since none of these check EM_ARM anyway, to just add it to the strchr used, rather than trying to make things overly complicated. initcall_debug improves: dmesg_before.txt: initcall $x+0x0/0x154 [sg] returned 0 after 26331 usecs dmesg_after.txt: initcall init_sg+0x0/0x154 [sg] returned 0 after 15461 usecs Signed-off-by: Kyle McMartin <kyle@redhat.com> Acked-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2014-06-10kbuild: trivial - use tabs for code indent where possibleMasahiro Yamada1-1/+1
Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com> Signed-off-by: Michal Marek <mmarek@suse.cz>
2014-03-17kallsyms: fix percpu vars on x86-64 with relocation.Rusty Russell1-0/+21
x86-64 has a problem: per-cpu variables are actually represented by their absolute offsets within the per-cpu area, but the symbols are not emitted as absolute. Thus kallsyms naively creates them as offsets from _text, meaning their values change if the kernel is relocated (especially noticeable with CONFIG_RANDOMIZE_BASE): $ egrep ' (gdt_|_(stext|_per_cpu_))' /root/kallsyms.nokaslr 0000000000000000 D __per_cpu_start 0000000000004000 D gdt_page 0000000000014280 D __per_cpu_end ffffffff810001c8 T _stext ffffffff81ee53c0 D __per_cpu_offset $ egrep ' (gdt_|_(stext|_per_cpu_))' /root/kallsyms.kaslr1 000000001f200000 D __per_cpu_start 000000001f204000 D gdt_page 000000001f214280 D __per_cpu_end ffffffffa02001c8 T _stext ffffffffa10e53c0 D __per_cpu_offset Making them absolute symbols is the Right Thing, but requires fixes to the relocs tool. So for the moment, we add a --absolute-percpu option which makes them absolute from a kallsyms perspective: $ egrep ' (gdt_|_(stext|_per_cpu_))' /proc/kallsyms # no KASLR 0000000000000000 A __per_cpu_start 000000000000a000 A gdt_page 0000000000013040 A __per_cpu_end ffffffff802001c8 T _stext ffffffff8099b180 D __per_cpu_offset ffffffff809a3000 D __per_cpu_load $ egrep ' (gdt_|_(stext|_per_cpu_))' /proc/kallsyms # With KASLR 0000000000000000 A __per_cpu_start 000000000000a000 A gdt_page 0000000000013040 A __per_cpu_end ffffffff89c001c8 T _stext ffffffff8a39d180 D __per_cpu_offset ffffffff8a3a5000 D __per_cpu_load Based-on-the-original-screenplay-by: Andy Honig <ahonig@google.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Acked-by: Kees Cook <keescook@chromium.org>
2014-03-17kallsyms: generalize address range checkingKees Cook1-21/+32
This refactors the address range checks to be generalized instead of specific to text range checks, in preparation for other range checks. Also extracts logic for "is the symbol absolute" into a function. Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2014-03-10revert "kallsyms: fix absolute addresses for kASLR"Andrew Morton1-1/+2
Revert the recently applied 0f55159d091c ("kallsyms: fix absolute addresses for kASLR"). Kees said : This got NAKed, please don't apply -- this patch works for x86 and : ARM, but may cause problems for others: : : https://lkml.org/lkml/2014/2/24/718 It appears that Kees will be fixing all this up for 3.15. Cc: Andy Honig <ahonig@google.com> Cc: Kees Cook <keescook@chromium.org> Cc: Michal Marek <mmarek@suse.cz> Cc: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-03-04kallsyms: fix absolute addresses for kASLRAndy Honig1-2/+1
Currently symbols that are absolute addresses are incorrectly displayed in /proc/kallsyms if the kernel is loaded with kASLR. The problem was that the scripts/kallsyms.c file which generates the array of symbol names and addresses uses an relocatable value for all symbols, even absolute symbols. This patch fixes that. Several kallsyms output in different boot states for comparison: $ egrep '_(stext|_per_cpu_(start|end))' /root/kallsyms.nokaslr 0000000000000000 D __per_cpu_start 0000000000014280 D __per_cpu_end ffffffff810001c8 T _stext $ egrep '_(stext|_per_cpu_(start|end))' /root/kallsyms.kaslr1 000000001f200000 D __per_cpu_start 000000001f214280 D __per_cpu_end ffffffffa02001c8 T _stext $ egrep '_(stext|_per_cpu_(start|end))' /root/kallsyms.kaslr2 000000000d400000 D __per_cpu_start 000000000d414280 D __per_cpu_end ffffffff8e4001c8 T _stext $ egrep '_(stext|_per_cpu_(start|end))' /root/kallsyms.kaslr-fixed 0000000000000000 D __per_cpu_start 0000000000014280 D __per_cpu_end ffffffffadc001c8 T _stext Signed-off-by: Andy Honig <ahonig@google.com> Signed-off-by: Kees Cook <keescook@chromium.org> Cc: Michal Marek <mmarek@suse.cz> Cc: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-11-15Merge branch 'kbuild' of ↵Linus Torvalds1-0/+6
git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild Pull kbuild changes from Michal Marek: - LTO fixes, but the kallsyms part had to be reverted - Pass -Werror=implicit-int and -Werror=strict-prototypes to the compiler by default - snprintf fix in modpost - remove GREP_OPTIONS from the environment to be immune against exotic grep option settings * 'kbuild' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild: kallsyms: Revert back to 128 max symbol length Kbuild: Ignore GREP_OPTIONS env variable scripts: kallsyms: Use %zu to print 'size_t' scripts/bloat-o-meter: use .startswith rather than fragile slicing scripts/bloat-o-meter: ignore changes in the size of linux_banner kbuild: replace unbounded sprintf call in modpost kbuild, bloat-o-meter: fix static detection Kbuild: Handle longer symbols in kallsyms.c kbuild: Increase kallsyms max symbol length Makefile: enable -Werror=implicit-int and -Werror=strict-prototypes by default
2013-11-13kallsyms: Revert back to 128 max symbol lengthMichal Marek1-1/+1
This reverts commits f3462aa (Kbuild: Handle longer symbols in kallsyms.c) and eea0e9c (kbuild: Increase kallsyms max symbol length) except for the added overflow check. The reason is a regression caused by increasing the buffer: http://marc.info/?l=linux-kernel&m=138387700415675. Reported-by: Fengguang Wu <fengguang.wu@intel.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Joe Mario <jmario@redhat.com> Signed-off-by: Michal Marek <mmarek@suse.cz>
2013-11-08scripts: kallsyms: Use %zu to print 'size_t'Fabio Estevam1-1/+1
Commit f3462aa95 (Kbuild: Handle longer symbols in kallsyms.c) introduced the following warning on ARM: scripts/kallsyms.c:121:4: warning: format '%lu' expects argument of type 'long unsigned int', but argument 4 has type 'size_t' [-Wformat] Use %zu to print 'size_t'. Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com> Signed-off-by: Michal Marek <mmarek@suse.cz>
2013-11-06Kbuild: Handle longer symbols in kallsyms.cAndi Kleen1-1/+7
Also warn for too long symbols v2: Add missing newline. Use 255 max (Joe Perches) Signed-off-by: Andi Kleen <ak@linux.intel.com> Signed-off-by: Michal Marek <mmarek@suse.cz>
2013-11-02scripts/kallsyms: filter symbols not in kernel address spaceMing Lei1-1/+11
This patch uses CONFIG_PAGE_OFFSET to filter symbols which are not in kernel address space because these symbols are generally for generating code purpose and can't be run at kernel mode, so we needn't keep them in /proc/kallsyms. For example, on ARM there are some symbols which may be linked in relocatable code section, then perf can't parse symbols any more from /proc/kallsyms, this patch fixes the problem (introduced b9b32bf70f2fb710b07c94e13afbc729afe221da) Cc: Russell King <linux@arm.linux.org.uk> Cc: linux-arm-kernel@lists.infradead.org Cc: Michal Marek <mmarek@suse.cz> Signed-off-by: Ming Lei <tom.leiming@gmail.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Cc: stable@vger.kernel.org
2011-05-12scripts/kallsyms.c: fix potential segfaultXiaochen Wang1-0/+2
Description: This bug hardly appears during real kernel compiling, because the vmlinux symbols table is huge. But we can still catch it under strict condition , as follows. $ echo "c101b97b T do_fork" | ./scripts/kallsyms --all-symbols #include <asm/types.h> ...... ...... .globl kallsyms_token_table ALGN kallsyms_token_table: Segmentation fault (core dumped) $ If symbols table is small, all entries in token_profit[0x10000] may decrease to 0 after several calls of compress_symbols() in optimize_result(). In that case, find_best_token() always return 0 and best_table[i] is set to "\0\0" and best_table_len[i] is set to 2. As a result, expand_symbol(best_table[0]="\0\0", best_table_len[0]=2, buf) in write_src() will run in infinite recursion until stack overflows, causing segfault. This patch checks the find_best_token() return value. If all entries in token_profit[0x10000] become 0 according to return value, it breaks the loop in optimize_result(). And expand_symbol() works well when best_table_len[i] is 0. Signed-off-by: Xiaochen Wang <wangxiaochen0@gmail.com> Acked-by: Paulo Marques <pmarques@grupopie.com> Signed-off-by: Michal Marek <mmarek@suse.cz>
2010-09-29scripts/kallsyms: Enable error messages while hush up unnecessary warningsJean Sacren1-6/+2
As no error was handled, we wouldn't be able to know when an error does occur. The fix preserves error messages while it doesn't let unnecessary compiling warnings show up. Signed-off-by: Jean Sacren <sakiwit@gmail.com> Signed-off-by: Michal Marek <mmarek@suse.cz>
2010-02-02scripts/kallsyms: suppress build warningHimanshu Chauhan1-2/+4
Suppress a warn_unused_result warning. fgets is called as a part of error handling. It is called just to drop a line and return immediately. read_map is reading the file in a loop and read_symbol reads line by line. So I think there is no point in using return value for useful checking. Other checks like 3 items were returned or !EOF have already been done. Signed-off-by: Himanshu Chauhan <hschauhan@nulltrace.org> Cc: WANG Cong <xiyou.wangcong@gmail.com> Cc: Michal Marek <mmarek@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Michal Marek <mmarek@suse.cz>
2009-09-23kallsyms: fix segfault in prefix_underscores_count()Paul Mundt1-1/+1
Commit b478b782e110fdb4135caa3062b6d687e989d994 "kallsyms, tracing: output more proper symbol name" introduces a "bugfix" that introduces a segfault in kallsyms in my configurations. The cause is the introduction of prefix_underscores_count() which attempts to count underscores, even in symbols that do not have them. As a result, it just uselessly runs past the end of the buffer until it crashes: CC init/version.o LD init/built-in.o LD .tmp_vmlinux1 KSYM .tmp_kallsyms1.S /bin/sh: line 1: 16934 Done sh-linux-gnu-nm -n .tmp_vmlinux1 16935 Segmentation fault | scripts/kallsyms > .tmp_kallsyms1.S make: *** [.tmp_kallsyms1.S] Error 139 This simplifies the logic and just does a straightforward count. Signed-off-by: Paul Mundt <lethal@linux-sh.org> Reviewed-by: Li Zefan <lizf@cn.fujitsu.com> Cc: Lai Jiangshan <laijs@cn.fujitsu.com> Cc: Sam Ravnborg <sam@ravnborg.org> Cc: Paulo Marques <pmarques@grupopie.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: <stable@kernel.org> [2.6.30.x, 2.6.31.x] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-20kallsyms: fix inverted valid symbol checkingMike Frysinger1-3/+3
The previous commit (17b1f0de) introduced a slightly broken consolidation of the memory text range checking. Signed-off-by: Mike Frysinger <vapier@gentoo.org> Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
2009-06-14kallsyms: generalize text region handlingMike Frysinger1-26/+61
Signed-off-by: Mike Frysinger <vapier@gentoo.org> Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
2009-06-14kallsyms: support kernel symbols in Blackfin on-chip memoryRobin Getz1-1/+12
The Blackfin arch has a discontiguous .text layout due to having on-chip instruction memory and no virtual memory support. As such, we need to add explicit checks for these additional .text regions. Signed-off-by: Robin Getz <robin.getz@analog.com> Signed-off-by: Bryan Wu <cooloney@kernel.org> Signed-off-by: Mike Frysinger <vapier@gentoo.org> Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
2009-03-14kallsyms, tracing: output more proper symbol nameLai Jiangshan1-0/+57
Impact: bugfix, output more reliable symbol lookup result Debug tools(dump_stack(), ftrace...) are like to print out symbols. But it is always print out the first aliased symbol.(Aliased symbols are symbols with the same address), and the first aliased symbol is sometime not proper. # echo function_graph > current_tracer # cat trace ...... 1) 1.923 us | select_nohz_load_balancer(); 1) + 76.692 us | } 1) | default_idle() { 1) ==========> | __irqentry_text_start() { 1) 0.000 us | native_apic_mem_write(); 1) | irq_enter() { 1) 0.000 us | idle_cpu(); 1) | tick_check_idle() { 1) 0.000 us | tick_check_oneshot_broadcast(); 1) | tick_nohz_stop_idle() { ...... It's very embarrassing, it ouputs "__irqentry_text_start()", actually, it should output "smp_apic_timer_interrupt()". (these two symbol are the same address, but "__irqentry_text_start" is deemed to the first aliased symbol by scripts/kallsyms) This patch puts symbols like "__irqentry_text_start" to the second aliased symbols. And a more proper symbol name becomes the first. Aliased symbols mostly come from linker script. The solution is guessing "is this symbol defined in linker script", the symbols defined in linker script will not become the first aliased symbol. And if symbols are found to be equal in this "linker script provided" criteria, symbols are sorted by the number of prefix underscores. Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> Acked-by: Sam Ravnborg <sam@ravnborg.org> Reviewed-by: Paulo Marques <pmarques@grupopie.com> LKML-Reference: <49BA06E2.7080807@cn.fujitsu.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-14Revert "kbuild: strip generated symbols from *.ko"Sam Ravnborg1-8/+13
This reverts commit ad7a953c522ceb496611d127e51e278bfe0ff483. And commit: ("allow stripping of generated symbols under CONFIG_KALLSYMS_ALL") 9bb482476c6c9d1ae033306440c51ceac93ea80c These stripping patches has caused a set of issues: 1) People have reported compatibility issues with binutils due to lack of support for `--strip-unneeded-symbols' with objcopy 2.15.92.0.2 Reported by: Wenji 2) ccache and distcc no longer works as expeced Reported by: Ted, Roland, + others 3) The installed modules increased a lot in size Reported by: Ted, Davej + others Reported-by: Wenji Huang <wenji.huang@oracle.com> Reported-by: "Theodore Ts'o" <tytso@mit.edu> Reported-by: Dave Jones <davej@redhat.com> Reported-by: Roland McGrath <roland@redhat.com> Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
2008-12-19allow stripping of generated symbols under CONFIG_KALLSYMS_ALLJan Beulich1-13/+8
Building upon parts of the module stripping patch, this patch introduces similar stripping for vmlinux when CONFIG_KALLSYMS_ALL=y. Using CONFIG_KALLSYMS_STRIP_GENERATED reduces the overhead of CONFIG_KALLSYMS_ALL from 245k/310k to 65k/80k for the (i386/x86-64) kernels I tested with. The patch also does away with the need to special case the kallsyms- internal symbols by making them available even in the first linking stage. While it is a generated file, the patch includes the changes to scripts/genksyms/keywords.c_shipped, as I'm unsure what the procedure here is. Signed-off-by: Jan Beulich <jbeulich@novell.com> Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
2008-05-19kbuild: filter away debug symbols from kernel symbolsSam Ravnborg1-0/+3
Andi Kleen <andi@firstfloor.org> reported that he saw a lot of symbols like this: 0000000000000b24 N DW.aio.h.903a6d92.2 0000000000000bce N DW.task_io_accounting.h.8d8de327.0 0000000000000bec N DW.hrtimer.h.c23659c6.0 in his System.map / kallsyms output. Simple solution is to skip all debugging symbols (they are marked 'N'). Signed-off-by: Sam Ravnborg <sam@ravnborg.org> Cc: Paulo Marques <pmarques@grupopie.com>
2008-04-30kallsyms: nuke all ChangeLog, this should be logged by gitBryan Wu1-6/+0
Pointed out by Paulo: "When I wrote this initially, it was a mistake to add a Changelog in the first place, but I didn't know better at the time. If you're going to make changes to this file, please remove all the Changelog, instead of adding more entries to it. The 'Changelog' should be kept by the version control system, and not the source code itself." Cc: Paulo Marques <pmarques@grupopie.com> Signed-off-by: Bryan Wu <cooloney@kernel.org> Acked-by: Paulo Marques <pmarques@grupopie.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-06kallsyms should prefer non weak symbolsPaulo Marques1-3/+34
When resolving symbol names from addresses with aliased symbol names, kallsyms_lookup always returns the first symbol, even if it is a weak symbol. This patch changes this by sorting the symbols with the weak symbols last before feeding them to the kernel. This way the kernel runtime isn't changed at all, only the kallsyms build system is changed. Another side effect is that the symbols get sorted by address, too. So, even if future binutils version have some bug in "nm" that makes it fail to correctly sort symbols by address, the kernel won't be affected by this. Mathieu says: I created a module in LTTng that uses kallsyms to get the symbol corresponding to a specific system call address. Unfortunately, all the unimplemented syscalls were all referring to the (same) weak symbol identifying an unrelated system call rather that sys_ni (or whatever non-weak symbol would be expected). Kallsyms was dumbly returning the first symbol that matched. This patch makes sure kallsyms returns the non-weak symbol when there is one, which seems to be the expected result. [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> Looks-great-to: Rusty Russell <rusty@rustcorp.com.au> Cc: Sam Ravnborg <sam@ravnborg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-06remove support for un-needed _extratext sectionRobin Getz1-14/+10
When passing a zero address to kallsyms_lookup(), the kernel thought it was a valid kernel address, even if it is not. This is because is_ksym_addr() called is_kernel_extratext() and checked against labels that don't exist on many archs (which default as zero). Since PPC was the only kernel which defines _extra_text, (in 2005), and no longer needs it, this patch removes _extra_text support. For some history (provided by Jon): http://ozlabs.org/pipermail/linuxppc-dev/2005-September/019734.html http://ozlabs.org/pipermail/linuxppc-dev/2005-September/019736.html http://ozlabs.org/pipermail/linuxppc-dev/2005-September/019751.html [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Robin Getz <rgetz@blackfin.uclinux.org> Cc: David Woodhouse <dwmw2@infradead.org> Cc: Jon Loeliger <jdl@freescale.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Sam Ravnborg <sam@ravnborg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-19Merge git://git.kernel.org/pub/scm/linux/kernel/git/sam/kbuildLinus Torvalds1-4/+13
* git://git.kernel.org/pub/scm/linux/kernel/git/sam/kbuild: (33 commits) xtensa: use DATA_DATA in xtensa powerpc: add missing DATA_DATA to powerpc cris: use DATA_DATA in cris kallsyms: remove usage of memmem and _GNU_SOURCE from scripts/kallsyms.c kbuild: use -fno-optimize-sibling-calls unconditionally kconfig: reset generated values only if Kconfig and .config agree. kbuild: fix the warning when running make tags kconfig: strip 'CONFIG_' automatically in kernel configuration search kbuild: use POSIX BRE in headers install target Whitelist references from __dbe_table to .init modpost white list pattern adjustment kbuild: do section mismatch check on full vmlinux kbuild: whitelist references from variables named _timer to .init.text kbuild: remove hardcoded _logo names from modpost kbuild: remove hardcoded apic_es7000 from modpost kbuild: warn about references from .init.text to .exit.text kbuild: consolidate section checks kbuild: refactor code in modpost to improve maintainability kbuild: ignore section mismatch warnings originating from .note section kbuild: .paravirtprobe section is obsolete, so modpost doesn't need to handle it ...
2007-07-17kallsyms: make KSYM_NAME_LEN include space for trailing '\0'Tejun Heo1-2/+2
KSYM_NAME_LEN is peculiar in that it does not include the space for the trailing '\0', forcing all users to use KSYM_NAME_LEN + 1 when allocating buffer. This is nonsense and error-prone. Moreover, when the caller forgets that it's very likely to subtly bite back by corrupting the stack because the last position of the buffer is always cleared to zero. This patch increments KSYM_NAME_LEN by one and updates code accordingly. * off-by-one bug in asm-powerpc/kprobes.h::kprobe_lookup_name() macro is fixed. * Where MODULE_NAME_LEN and KSYM_NAME_LEN were used together, MODULE_NAME_LEN was treated as if it didn't include space for the trailing '\0'. Fix it. Signed-off-by: Tejun Heo <htejun@gmail.com> Acked-by: Paulo Marques <pmarques@grupopie.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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