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2018-09-19ftrace: Build with CPPFLAGS to get -Qunused-argumentsJoel Stanley1-1/+1
When building to record the mcount locations the kernel uses KBUILD_CFLAGS but not KBUILD_CPPFLAGS. This means it lacks -Qunused-arguments when building with clang, resulting in a lot of noisy warnings. Signed-off-by: Joel Stanley <joel@jms.id.au> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-08-30objtool: Remove workaround for unreachable warnings from old GCCMasahiro Yamada1-2/+0
Commit cafa0010cd51 ("Raise the minimum required gcc version to 4.6") bumped the minimum GCC version to 4.6 for all architectures. This effectively reverts commit da541b20021c ("objtool: Skip unreachable warnings for GCC 4.4 and older"), which was a workaround for GCC 4.4 or older. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Michal Marek <michal.lkml@markovi.net> Cc: linux-kbuild@vger.kernel.org Link: https://lkml.kernel.org/r/1535341183-19994-1-git-send-email-yamada.masahiro@socionext.com
2018-08-24kbuild: rename LDFLAGS to KBUILD_LDFLAGSMasahiro Yamada1-3/+3
Commit a0f97e06a43c ("kbuild: enable 'make CFLAGS=...' to add additional options to CC") renamed CFLAGS to KBUILD_CFLAGS. Commit 222d394d30e7 ("kbuild: enable 'make AFLAGS=...' to add additional options to AS") renamed AFLAGS to KBUILD_AFLAGS. Commit 06c5040cdb13 ("kbuild: enable 'make CPPFLAGS=...' to add additional options to CPP") renamed CPPFLAGS to KBUILD_CPPFLAGS. For some reason, LDFLAGS was not renamed. Using a well-known variable like LDFLAGS may result in accidental override of the variable. Kbuild generally uses KBUILD_ prefixed variables for the internally appended options, so here is one more conversion to sanitize the naming convention. I did not touch Makefiles under tools/ since the tools build system is a different world. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Reviewed-by: Palmer Dabbelt <palmer@sifive.com>
2018-08-24kbuild: pass LDFLAGS to recordmcount.plMasahiro Yamada1-1/+1
Since commit 0fbe9a245c60 ("microblaze: add endianness options to LDFLAGS instead of LD"), you cannot build the kernel for microblaze with CONFIG_DYNAMIC_FTRACE. Fixes: 0fbe9a245c60 ("microblaze: add endianness options to LDFLAGS instead of LD") Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-08-20Merge tag 'trace-v4.19' of ↵Linus Torvalds1-6/+3
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace Pull tracing updates from Steven Rostedt: - Restructure of lockdep and latency tracers This is the biggest change. Joel Fernandes restructured the hooks from irqs and preemption disabling and enabling. He got rid of a lot of the preprocessor #ifdef mess that they caused. He turned both lockdep and the latency tracers to use trace events inserted in the preempt/irqs disabling paths. But unfortunately, these started to cause issues in corner cases. Thus, parts of the code was reverted back to where lockdep and the latency tracers just get called directly (without using the trace events). But because the original change cleaned up the code very nicely we kept that, as well as the trace events for preempt and irqs disabling, but they are limited to not being called in NMIs. - Have trace events use SRCU for "rcu idle" calls. This was required for the preempt/irqs off trace events. But it also had to not allow them to be called in NMI context. Waiting till Paul makes an NMI safe SRCU API. - New notrace SRCU API to allow trace events to use SRCU. - Addition of mcount-nop option support - SPDX headers replacing GPL templates. - Various other fixes and clean ups. - Some fixes are marked for stable, but were not fully tested before the merge window opened. * tag 'trace-v4.19' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (44 commits) tracing: Fix SPDX format headers to use C++ style comments tracing: Add SPDX License format tags to tracing files tracing: Add SPDX License format to bpf_trace.c blktrace: Add SPDX License format header s390/ftrace: Add -mfentry and -mnop-mcount support tracing: Add -mcount-nop option support tracing: Avoid calling cc-option -mrecord-mcount for every Makefile tracing: Handle CC_FLAGS_FTRACE more accurately Uprobe: Additional argument arch_uprobe to uprobe_write_opcode() Uprobes: Simplify uprobe_register() body tracepoints: Free early tracepoints after RCU is initialized uprobes: Use synchronize_rcu() not synchronize_sched() tracing: Fix synchronizing to event changes with tracepoint_synchronize_unregister() ftrace: Remove unused pointer ftrace_swapper_pid tracing: More reverting of "tracing: Centralize preemptirq tracepoints and unify their usage" tracing/irqsoff: Handle preempt_count for different configs tracing: Partial revert of "tracing: Centralize preemptirq tracepoints and unify their usage" tracing: irqsoff: Account for additional preempt_disable trace: Use rcu_dereference_raw for hooks from trace-event subsystem tracing/kprobes: Fix within_notrace_func() to check only notrace functions ...
2018-08-15tracing: Avoid calling cc-option -mrecord-mcount for every MakefileVasily Gorbik1-6/+3
Currently if CONFIG_FTRACE_MCOUNT_RECORD is enabled -mrecord-mcount compiler flag support is tested for every Makefile. Top 4 cc-option usages: 511 -mrecord-mcount 11 -fno-stack-protector 9 -Wno-override-init 2 -fsched-pressure To address that move cc-option from scripts/Makefile.build to top Makefile and export CC_USING_RECORD_MCOUNT to be used in original place. While doing that also add -mrecord-mcount to CC_FLAGS_FTRACE (if gcc actually supports it). Link: http://lkml.kernel.org/r/patch-2.thread-aa7b8d.git-de935bace15a.your-ad-here.call-01533557518-ext-9465@work.hours Acked-by: Andi Kleen <ak@linux.intel.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-08-09kbuild: remove deprecated host-progs variableMasahiro Yamada1-7/+0
The host-progs has been kept as an alias of hostprogs-y for a long time (at least since the beginning of Git era), with the clear prompt: Usage of host-progs is deprecated. Please replace with hostprogs-y! Enough time for the migration has passed. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Acked-by: Max Filippov <jcmvbkbc@gmail.com>
2018-07-06kbuild: remove duplicated comments about PHONYMasahiro Yamada1-3/+0
The comment is the same as in the top-level Makefile. Also, the comments contain typos: - the .PHONY variable -> the PHONY variable - se we can ... -> so we can ... Instead of fixing the typos, just remove the duplicated comments. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-06-21tracing: Fix SKIP_STACK_VALIDATION=1 build due to bad merge with -mrecord-mcountGreg Thelen1-1/+1
Non gcc-5 builds with CONFIG_STACK_VALIDATION=y and SKIP_STACK_VALIDATION=1 fail. Example output: /bin/sh: init/.tmp_main.o: Permission denied commit 96f60dfa5819 ("trace: Use -mcount-record for dynamic ftrace"), added a mismatched endif. This causes cmd_objtool to get mistakenly set. Relocate endif to balance the newly added -record-mcount check. Link: http://lkml.kernel.org/r/20180608214746.136554-1-gthelen@google.com Fixes: 96f60dfa5819 ("trace: Use -mcount-record for dynamic ftrace") Acked-by: Andi Kleen <ak@linux.intel.com> Tested-by: David Rientjes <rientjes@google.com> Signed-off-by: Greg Thelen <gthelen@google.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-06-06Merge tag 'trace-v4.18' of ↵Linus Torvalds1-0/+6
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace Pull tracing updates from Steven Rostedt: "One new feature was added to ftrace, which is the trace_marker now supports triggers. For example: # cd /sys/kernel/debug/tracing # echo 'snapshot' > events/ftrace/print/trigger # echo 'cause snapshot' > trace_marker The rest of the changes are various clean ups and also one stable fix that was added late in the cycle" * tag 'trace-v4.18' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (21 commits) tracing: Use match_string() instead of open coding it in trace_set_options() branch-check: fix long->int truncation when profiling branches ring-buffer: Fix typo in comment ring-buffer: Fix a bunch of typos in comments tracing/selftest: Add test to test simple snapshot trigger for trace_marker tracing/selftest: Add test to test hist trigger between kernel event and trace_marker tracing/selftest: Add selftests to test trace_marker histogram triggers ftrace/selftest: Fix reset_trigger() to handle triggers with filters ftrace/selftest: Have the reset_trigger code be a bit more careful tracing: Document trace_marker triggers tracing: Allow histogram triggers to access ftrace internal events tracing: Prevent further users of zero size static arrays in trace events tracing: Have zero size length in filter logic be full string tracing: Add trigger file for trace_markers tracefs/ftrace/print tracing: Do not show filter file for ftrace internal events tracing: Add brackets in ftrace event dynamic arrays tracing: Have event_trace_init() called by trace_init_tracefs() tracing: Add __find_event_file() to find event files without restrictions tracing: Do not reference event data in post call triggers tracepoints: Fix the descriptions of tracepoint_probe_register{_prio} ...
2018-05-28trace: Use -mcount-record for dynamic ftraceAndi Kleen1-0/+6
gcc 5 supports a new -mcount-record option to generate ftrace tables directly. This avoids the need to run record_mcount manually. Use this option when available. So far doesn't use -mcount-nop, which also exists now. This is needed to make ftrace work with LTO because the normal record-mcount script doesn't run over the link time output. It should also improve build times slightly in the general case. Link: http://lkml.kernel.org/r/20171127213423.27218-12-andi@firstfloor.org Signed-off-by: Andi Kleen <ak@linux.intel.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-05-17kbuild: remove CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIXMasahiro Yamada1-6/+1
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. Clean up the rest of scripts, and remove the Kconfig entry. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
2018-05-17genksyms: remove symbol prefix supportMasahiro Yamada1-2/+0
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 -s (--symbol-prefix) option is unnecessary. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
2018-04-07kbuild: mark $(targets) as .SECONDARY and remove .PRECIOUS markersMasahiro Yamada1-3/+7
GNU Make automatically deletes intermediate files that are updated in a chain of pattern rules. Example 1) %.dtb.o <- %.dtb.S <- %.dtb <- %.dts Example 2) %.o <- %.c <- %.c_shipped A couple of makefiles mark such targets as .PRECIOUS to prevent Make from deleting them, but the correct way is to use .SECONDARY. .SECONDARY Prerequisites of this special target are treated as intermediate files but are never automatically deleted. .PRECIOUS When make is interrupted during execution, it may delete the target file it is updating if the file was modified since make started. If you mark the file as precious, make will never delete the file if interrupted. Both can avoid deletion of intermediate files, but the difference is the behavior when Make is interrupted; .SECONDARY deletes the target, but .PRECIOUS does not. The use of .PRECIOUS is relatively rare since we do not want to keep partially constructed (possibly corrupted) targets. Another difference is that .PRECIOUS works with pattern rules whereas .SECONDARY does not. .PRECIOUS: $(obj)/%.lex.c works, but .SECONDARY: $(obj)/%.lex.c has no effect. However, for the reason above, I do not want to use .PRECIOUS which could cause obscure build breakage. The targets specified as .SECONDARY must be explicit. $(targets) contains all targets that need to include .*.cmd files. So, the intermediates you want to keep are mostly in there. Therefore, mark $(targets) as .SECONDARY. It means primary targets are also marked as .SECONDARY, but I do not see any drawback for this. I replaced some .SECONDARY / .PRECIOUS markers with 'targets'. This will make Kbuild search for non-existing .*.cmd files, but this is not a noticeable performance issue. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Acked-by: Frank Rowand <frowand.list@gmail.com> Acked-by: Ingo Molnar <mingo@kernel.org>
2018-04-07kbuild: rename *-asn1.[ch] to *.asn1.[ch]Masahiro Yamada1-2/+2
Our convention is to distinguish file types by suffixes with a period as a separator. *-asn1.[ch] is a different pattern from other generated sources such as *.lex.c, *.tab.[ch], *.dtb.S, etc. More confusing, files with '-asn1.[ch]' are generated files, but '_asn1.[ch]' are checked-in files: net/netfilter/nf_conntrack_h323_asn1.c include/linux/netfilter/nf_conntrack_h323_asn1.h include/linux/sunrpc/gss_asn1.h Rename generated files to *.asn1.[ch] for consistency. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-04-07kbuild: add %.dtb.S and %.dtb to 'targets' automaticallyMasahiro Yamada1-1/+3
Another common pattern that consists of chained commands is to compile a DTB as binary data into the kernel image or a module. It is used in several places in the source tree. Support it in the core Makefile. $(call if_changed,dt_S_dtb) is more suitable than $(call cmd,dt_S_dtb) in case cmd_dt_S_dtb is changed in the future. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Acked-by: Frank Rowand <frowand.list@gmail.com>
2018-04-07kbuild: add %.lex.c and %.tab.[ch] to 'targets' automaticallyMasahiro Yamada1-0/+11
Files generated by if_changed* must be added to 'targets' to include *.cmd files. Otherwise, they would be regenerated every time. The build system automatically adds objects to 'targets' where appropriate, such as obj-y, extra-y, etc. but does nothing for intermediate files. So, each Makefile needs to add them by itself. There are some common cases where objects are generated by chained rules. Lexers and parsers are compiled like follows: %.lex.o <- %.lex.c <- %.l %.tab.o <- %.tab.c <- %.y They are common patterns, so it is reasonable to take care of them in the core Makefile instead of requiring each Makefile to do so. At this moment, you cannot delete 'target += zconf.lex.c' in the Kconfig Makefile because zconf.lex.c is included from zconf.tab.c instead of being compiled separately. It should be deleted after Kconfig is more refactored. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Acked-by: Frank Rowand <frowand.list@gmail.com>
2018-03-26kbuild: clean up link rule of composite modulesMasahiro Yamada1-3/+1
cmd_link_multi-link is used only for cmd_link_multi-m. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-03-26kbuild: clean up archive rule of built-in.aMasahiro Yamada1-9/+4
With the incremental linking entirely dropped, we can simplify the Makefile. While I am here, I renamed cmd_link_o_target to cmd_ar_builtin. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-03-26kbuild: remove partial section mismatch detection for built-in.aMasahiro Yamada1-2/+1
When built-in.o was incrementally linked with 'ld -r', the section mismatch analysis for the individual built-in.o was possible when CONFIG_DEBUG_SECTION_MISMATCH was enabled. With the migration to the thin archive, built-in.a (former, built-in.o) is no longer an ELF file. So, the modpost does nothing useful. scripts/mod/modpost.c just checks the header to bail out, as follows: /* Is this a valid ELF file? */ if ((hdr->e_ident[EI_MAG0] != ELFMAG0) || (hdr->e_ident[EI_MAG1] != ELFMAG1) || (hdr->e_ident[EI_MAG2] != ELFMAG2) || (hdr->e_ident[EI_MAG3] != ELFMAG3)) { /* Not an ELF file - silently ignore it */ return 0; } We have the full analysis in the final link stage anyway, so we would not miss the section mismatching. I do not see a good reason to require extra linking only for the purpose of the per-directory analysis. Just get rid of this part. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-03-26kbuild: link $(real-obj-y) instead of $(obj-y) into built-in.aMasahiro Yamada1-14/+7
In Kbuild, Makefiles can add the same object to obj-y multiple times. So, obj-y += foo.o obj-y += foo.o is fine. However, this is not true when the same object is added multiple times via composite objects. For example, obj-y += foo.o bar.o foo-objs := foo-bar-common.o foo-only.o bar-objs := foo-bar-common.o bar-only.o causes build error because two instances of foo-bar-common.o are linked into the vmlinux. Makefiles tend to invent ugly work-around, for example - lib/zstd/Makefile - drivers/net/ethernet/cavium/liquidio/Makefile The technique used in Kbuild to avoid the multiple definition error is to use $(filter $(obj-y), $^). Here, $^ lists the names of all the prerequisites with duplicated names removed. By replacing it with $(filter $(real-obj-y), $^) we can do likewise for composite objects. For built-in objects, we do not need to keep the composite object structure. We can simply expand them, and link $(real-obj-y) to built-in.a. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-03-26kbuild: rename real-objs-y/m to real-obj-y/mMasahiro Yamada1-12/+12
When I was refactoring Makefiles, I stupidly mistook 'real-obj-y' for 'real-objs-y' over and over again. Finally, I decide to rename it to 'real-obj-y'. This is consistent with 'obj-y', 'subdir-obj-y'. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-03-26kbuild: move modname and modname-multi close to modname_flagsMasahiro Yamada1-2/+0
Just a cosmetic change to put related code close together. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Reviewed-by: Cao jin <caoj.fnst@cn.fujitsu.com>
2018-03-26kbuild: simplify modname calculationMasahiro Yamada1-11/+1
modname can be calculated much more simply. If modname-multi is empty, it is a single-used object. So, modname = $(basetarget). Otherwise, modname = $(modname-multi). Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Reviewed-by: Cao jin <caoj.fnst@cn.fujitsu.com>
2018-03-26kbuild: rename built-in.o to built-in.aNicholas Piggin1-5/+5
Incremental linking is gone, so rename built-in.o to built-in.a, which is the usual extension for archive files. This patch does two things, first is a simple search/replace: git grep -l 'built-in\.o' | xargs sed -i 's/built-in\.o/built-in\.a/g' The second is to invert nesting of nested text manipulations to avoid filtering built-in.a out from libs-y2: -libs-y2 := $(filter-out %.a, $(patsubst %/, %/built-in.a, $(libs-y))) +libs-y2 := $(patsubst %/, %/built-in.a, $(filter-out %.a, $(libs-y))) Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-03-26kbuild: remove incremental linking optionNicholas Piggin1-21/+11
This removes the old `ld -r` incremental link option, which has not been selected by any architecture since June 2017. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-03-26kbuild: Improve portability of some sed invocationsMichael Forney1-1/+1
* Use BREs where EREs aren't necessary. * Pass -E instead of -r to use EREs. This will be standardized in the next POSIX revision[0]. GNU sed supports this since 4.2 (May 2009), and busybox since 1.22.0 (Jan 2014). * Use the [:space:] character class instead of ` \t` in bracket expressions. In bracket expressions, POSIX says that <backslash> loses its special meaning, so a conforming implementation cannot expand \t to <tab>[1]. * In BREs, use interval expressions (\{n,m\}) instead of non-standard features like \+ and \?. * Use a loop instead of -s flag. There are still plenty of other cases of non-standard sed invocations (use of ERE features in BREs, in-place editing), but this fixes some core ones. [0] http://austingroupbugs.net/view.php?id=528 [1] http://pubs.opengroup.org/onlinepubs/9699919799/basedefs/V1_chap09.html#tag_09_03_05 Signed-off-by: Michael Forney <forney@google.com> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-02-21objtool, retpolines: Integrate objtool with retpoline support more closelyPeter Zijlstra1-0/+2
Disable retpoline validation in objtool if your compiler sucks, and otherwise select the validation stuff for CONFIG_RETPOLINE=y (most builds would already have it set due to ORC). Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Thomas Gleixner <tglx@linutronix.de> Cc: Andy Lutomirski <luto@kernel.org> Cc: Arjan van de Ven <arjan@linux.intel.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: David Woodhouse <dwmw2@infradead.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-02-21objtool: Add module specific retpoline rulesPeter Zijlstra1-0/+2
David allowed retpolines in .init.text, except for modules, which will trip up objtool retpoline validation, fix that. Requested-by: David Woodhouse <dwmw2@infradead.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Arjan van de Ven <arjan@linux.intel.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: David Woodhouse <dwmw2@infradead.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-02-21objtool: Add retpoline validationPeter Zijlstra1-0/+4
David requested a objtool validation pass for CONFIG_RETPOLINE=y enabled builds, where it validates no unannotated indirect jumps or calls are left. Add an additional .discard.retpoline_safe section to allow annotating the few indirect sites that are required and safe. Requested-by: David Woodhouse <dwmw2@infradead.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: David Woodhouse <dwmw@amazon.co.uk> Acked-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Arjan van de Ven <arjan@linux.intel.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-01-17Merge branch 'x86-pti-for-linus' of ↵Linus Torvalds1-4/+10
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 pti bits and fixes from Thomas Gleixner: "This last update contains: - An objtool fix to prevent a segfault with the gold linker by changing the invocation order. That's not just for gold, it's a general robustness improvement. - An improved error message for objtool which spares tearing hairs. - Make KASAN fail loudly if there is not enough memory instead of oopsing at some random place later - RSB fill on context switch to prevent RSB underflow and speculation through other units. - Make the retpoline/RSB functionality work reliably for both Intel and AMD - Add retpoline to the module version magic so mismatch can be detected - A small (non-fix) update for cpufeatures which prevents cpu feature clashing for the upcoming extra mitigation bits to ease backporting" * 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: module: Add retpoline tag to VERMAGIC x86/cpufeature: Move processor tracing out of scattered features objtool: Improve error message for bad file argument objtool: Fix seg fault with gold linker x86/retpoline: Add LFENCE to the retpoline/RSB filling RSB macros x86/retpoline: Fill RSB on context switch for affected CPUs x86/kasan: Panic if there is not enough memory to boot
2018-01-16objtool: Fix seg fault with gold linkerJosh Poimboeuf1-4/+10
Objtool segfaults when the gold linker is used with CONFIG_MODVERSIONS=y and CONFIG_UNWINDER_ORC=y. With CONFIG_MODVERSIONS=y, the .o file gets passed to the linker before being passed to objtool. The gold linker seems to strip unused ELF symbols by default, which confuses objtool and causes the seg fault when it's trying to generate ORC metadata. Objtool should really be running immediately after GCC anyway, without a linker call in between. Change the makefile ordering so that objtool is called before the linker. Reported-and-tested-by: Markus <M4rkusXXL@web.de> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Fixes: ee9f8fce9964 ("x86/unwind: Add the ORC unwinder") Link: http://lkml.kernel.org/r/355f04da33581f4a3bf82e5b512973624a1e23a2.1516025651.git.jpoimboe@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-12-17Merge commit 'upstream-x86-entry' into WIP.x86/mmIngo Molnar1-1/+1
Pull in a minimal set of v4.15 entry code changes, for a base for the MM isolation patches. Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-11-25Merge tag 'kbuild-v4.15-2' of ↵Linus Torvalds1-2/+2
git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild Pull more Kbuild updates from Masahiro Yamada: - use 'pwd' instead of '/bin/pwd' for portability - clean up Makefiles - fix ld-option for clang - fix malloc'ed data size in Kconfig - fix parallel building along with coccicheck - fix a minor issue of package building - prompt to use "rpm-pkg" instead of "rpm" - clean up *.i and *.lst patterns by "make clean" * tag 'kbuild-v4.15-2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: kbuild: drop $(extra-y) from real-objs-y kbuild: clean up *.i and *.lst patterns by make clean kbuild: rpm: prompt to use "rpm-pkg" if "rpm" target is used kbuild: pkg: use --transform option to prefix paths in tar coccinelle: fix parallel build with CHECK=scripts/coccicheck kconfig/symbol.c: use correct pointer type argument for sizeof kbuild: Set KBUILD_CFLAGS before incl. arch Makefile kbuild: remove all dummy assignments to obj- kbuild: create built-in.o automatically if parent directory wants it kbuild: /bin/pwd -> pwd
2017-11-23Merge tag 'docs-4.15-2' of git://git.lwn.net/linuxLinus Torvalds1-0/+5
Pull documentation updates from Jonathan Corbet: "A few late-arriving docs updates that have no real reason to wait. There's a new "Co-Developed-by" tag described by Greg, and a build enhancement from Willy to generate docs warnings during a kernel build (but only when additional warnings have been requested in general)" * tag 'docs-4.15-2' of git://git.lwn.net/linux: Add optional check for bad kernel-doc comments Documentation: fix profile= options in kernel-parameters.txt documentation/svga.txt: update outdated file kokr/memory-barriers.txt: Fix typo in paring example kokr/memory-barriers/txt: Replace uses of "transitive" Documentation/process: add Co-Developed-by: tag for patches with multiple authors
2017-11-20Add optional check for bad kernel-doc commentsMatthew Wilcox1-0/+5
Implement a '-none' output mode for kernel-doc which will only output warning messages, and suppresses the warning message about there being no kernel-doc in the file. If the build has requested additional warnings, automatically check all .c files. This patch does not check .h files. Enabling the warning by default would add about 1300 warnings, so it's default off for now. People who care can use this to check they didn't break the docs and maybe we'll get all the warnings fixed and be able to enable this check by default in the future. Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2017-11-18kbuild: create built-in.o automatically if parent directory wants itMasahiro Yamada1-2/+2
"obj-y += foo/" syntax requires Kbuild to visit the "foo" subdirectory and link built-in.o from that directory. This means foo/Makefile is responsible for creating built-in.o even if there is no object to link (in this case, built-in.o is an empty archive). We have had several fixups like commit 4b024242e8a4 ("kbuild: Fix linking error built-in.o no such file or directory"), then ended up with a complex condition as follows: ifneq ($(strip $(obj-y) $(obj-m) $(obj-) $(subdir-m) $(lib-target)),) builtin-target := $(obj)/built-in.o endif We still have more cases not covered by the above, so we need to add obj- := dummy.o in several places just for creating empty built-in.o. A key point is, the parent Makefile knows whether built-in.o is needed or not. If a subdirectory needs to create built-in.o, its parent can tell the fact when descending. If non-empty $(need-builtin) flag is passed from the parent, built-in.o should be created. $(obj-y) should be still checked to support the single target "%/". All of ugly tricks will go away. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
2017-11-17Merge tag 'kbuild-v4.15' of ↵Linus Torvalds1-12/+13
git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild Pull Kbuild updates from Masahiro Yamada: "One of the most remarkable improvements in this cycle is, Kbuild is now able to cache the result of shell commands. Some variables are expensive to compute, for example, $(call cc-option,...) invokes the compiler. It is not efficient to redo this computation every time, even when we are not actually building anything. Kbuild creates a hidden file ".cache.mk" that contains invoked shell commands and their results. The speed-up should be noticeable. Summary: - Fix arch build issues (hexagon, sh) - Clean up various Makefiles and scripts - Fix wrong usage of {CFLAGS,LDFLAGS}_MODULE in arch Makefiles - Cache variables that are expensive to compute - Improve cc-ldopton and ld-option for Clang - Optimize output directory creation" * tag 'kbuild-v4.15' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (30 commits) kbuild: move coccicheck help from scripts/Makefile.help to top Makefile sh: decompressor: add shipped files to .gitignore frv: .gitignore: ignore vmlinux.lds selinux: remove unnecessary assignment to subdir- kbuild: specify FORCE in Makefile.headersinst as .PHONY target kbuild: remove redundant mkdir from ./Kbuild kbuild: optimize object directory creation for incremental build kbuild: create object directories simpler and faster kbuild: filter-out PHONY targets from "targets" kbuild: remove redundant $(wildcard ...) for cmd_files calculation kbuild: create directory for make cache only when necessary sh: select KBUILD_DEFCONFIG depending on ARCH kbuild: fix linker feature test macros when cross compiling with Clang kbuild: shrink .cache.mk when it exceeds 1000 lines kbuild: do not call cc-option before KBUILD_CFLAGS initialization kbuild: Cache a few more calls to the compiler kbuild: Add a cache for generated variables kbuild: add forward declaration of default target to Makefile.asm-generic kbuild: remove KBUILD_SUBDIR_ASFLAGS and KBUILD_SUBDIR_CCFLAGS hexagon/kbuild: replace CFLAGS_MODULE with KBUILD_CFLAGS_MODULE ...
2017-11-16kbuild: optimize object directory creation for incremental buildMasahiro Yamada1-0/+5
The previous commit largely optimized the object directory creation. We can optimize it more for incremental build. There are already *.cmd files in the output directory. The existing *.cmd files have been picked up by $(wildcard ...). Obviously, directories containing them exist too, so we can skip "mkdir -p". With this, Kbuild runs almost zero "mkdir -p" in incremental building. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2017-11-16kbuild: create object directories simpler and fasterMasahiro Yamada1-9/+6
For the out-of-tree build, scripts/Makefile.build creates output directories, but this operation is not efficient. scripts/Makefile.lib calculates obj-dirs as follows: obj-dirs := $(dir $(multi-objs) $(obj-y)) Please notice $(sort ...) is not used here. Usually the result is as many "./" as objects here. For a lot of duplicated paths, the following command is invoked. _dummy := $(foreach d,$(obj-dirs), $(shell [ -d $(d) ] || mkdir -p $(d))) Then, the costly shell command is run over and over again. I see many points for optimization: [1] Use $(sort ...) to cut down duplicated paths before passing them to system call [2] Use single $(shell ...) instead of repeating it with $(foreach ...) This will reduce forking. [3] We can calculate obj-dirs more simply. Most of objects are already accumulated in $(targets). So, $(dir $(targets)) is fine and more comprehensive. I also removed ugly code in arch/x86/entry/vdso/Makefile. This is now really unnecessary. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Acked-by: Ingo Molnar <mingo@kernel.org> Tested-by: Douglas Anderson <dianders@chromium.org>
2017-11-16kbuild: filter-out PHONY targets from "targets"Masahiro Yamada1-1/+1
The variable "targets" contains object paths for which existing .*.cmd files should be included. scripts/Makefile.build automatically adds $(MAKECMDGOALS) to "targets" as follows: targets += $(extra-y) $(MAKECMDGOALS) $(always) The $(MAKECMDGOALS) is a PHONY target in several places. PHONY targets never create .*.cmd files. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2017-11-16kbuild: remove redundant $(wildcard ...) for cmd_files calculationMasahiro Yamada1-2/+1
I do not see any reason why $(wildcard ...) needs to be called twice for computing cmd_files. Remove the first one. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2017-11-07Merge branch 'linus' into x86/asm, to pick up fixes and resolve conflictsIngo Molnar1-1/+2
Conflicts: arch/x86/kernel/cpu/Makefile Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-11-02Kbuild: don't pass "-C" to preprocessor when processing linker scriptsLinus Torvalds1-1/+1
For some odd historical reason, we preprocessed the linker scripts with "-C", which keeps comments around. That makes no sense, since the comments are not meaningful for the build anyway. And it actually breaks things, since linker scripts can't have C++ style "//" comments in them, so keeping comments after preprocessing now limits us in odd and surprising ways in our header files for no good reason. The -C option goes back to pre-git and pre-bitkeeper times, but seems to have been historically used (along with "-traditional") for some odd-ball architectures (ia64, MIPS and SH). It probably didn't matter back then either, but might possibly have been used to minimize the difference between the original file and the pre-processed result. The reason for this may be lost in time, but let's not perpetuate it only because we can't remember why we did this crazy thing. This was triggered by the recent addition of SPDX lines to the source tree, where people apparently were confused about why header files couldn't use the C++ comment format. Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Greg KH <gregkh@linuxfoundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-11-02License cleanup: add SPDX GPL-2.0 license identifier to files with no licenseGreg Kroah-Hartman1-0/+1
Many source files in the tree are missing licensing information, which makes it harder for compliance tools to determine the correct license. By default all files without license information are under the default license of the kernel, which is GPL version 2. Update the files which contain no license information with the 'GPL-2.0' SPDX license identifier. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. How this work was done: Patches were generated and checked against linux-4.14-rc6 for a subset of the use cases: - file had no licensing information it it. - file was a */uapi/* one with no licensing information in it, - file was a */uapi/* one with existing licensing information, Further patches will be generated in subsequent months to fix up cases where non-standard license headers were used, and references to license had to be inferred by heuristics based on keywords. The analysis to determine which SPDX License Identifier to be applied to a file was done in a spreadsheet of side by side results from of the output of two independent scanners (ScanCode & Windriver) producing SPDX tag:value files created by Philippe Ombredanne. Philippe prepared the base worksheet, and did an initial spot review of a few 1000 files. The 4.13 kernel was the starting point of the analysis with 60,537 files assessed. Kate Stewart did a file by file comparison of the scanner results in the spreadsheet to determine which SPDX license identifier(s) to be applied to the file. She confirmed any determination that was not immediately clear with lawyers working with the Linux Foundation. Criteria used to select files for SPDX license identifier tagging was: - Files considered eligible had to be source code files. - Make and config files were included as candidates if they contained >5 lines of source - File already had some variant of a license header in it (even if <5 lines). All documentation files were explicitly excluded. The following heuristics were used to determine which SPDX license identifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time. In total, over 70 hours of logged manual review was done on the spreadsheet to determine the SPDX license identifiers to apply to the source files by Kate, Philippe, Thomas and, in some cases, confirmation by lawyers working with the Linux Foundation. Kate also obtained a third independent scan of the 4.13 code base from FOSSology, and compared selected files where the other two scanners disagreed against that SPDX file, to see if there was new insights. The Windriver scanner is based on an older version of FOSSology in part, so they are related. Thomas did random spot checks in about 500 files from the spreadsheets for the uapi headers and agreed with SPDX license identifier in the files he inspected. For the non-uapi files Thomas did random spot checks in about 15000 files. In initial set of patches against 4.14-rc6, 3 files were found to have copy/paste license identifier errors, and have been fixed to reflect the correct identifier. Additionally Philippe spent 10 hours this week doing a detailed manual inspection and review of the 12,461 patched files from the initial patch version early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correct This produced a worksheet with 20 files needing minor correction. This worksheet was then exported into 3 different .csv files for the different types of files to be modified. These .csv files were then reviewed by Greg. Thomas wrote a script to parse the csv files and add the proper SPDX tag to the file, in the format that the file expected. This script was further refined by Greg based on the output to detect more types of files automatically and to distinguish between header and source .c files (which need different comment types.) Finally Greg ran the script using the .csv files to generate the patches. Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-10-14x86/unwind: Rename unwinder config options to 'CONFIG_UNWINDER_*'Josh Poimboeuf1-1/+1
Rename the unwinder config options from: CONFIG_ORC_UNWINDER CONFIG_FRAME_POINTER_UNWINDER CONFIG_GUESS_UNWINDER to: CONFIG_UNWINDER_ORC CONFIG_UNWINDER_FRAME_POINTER CONFIG_UNWINDER_GUESS ... in order to give them a more logical config namespace. Suggested-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/73972fc7e2762e91912c6b9584582703d6f1b8cc.1507924831.git.jpoimboe@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-09-28objtool: Skip unreachable warnings for GCC 4.4 and olderJosh Poimboeuf1-0/+2
The kbuild bot occasionally reports warnings like: drivers/scsi/pcmcia/aha152x_core.o: warning: objtool: seldo_run()+0x130: unreachable instruction These warnings are always with GCC 4.4. That version of GCC sometimes places unreachable instructions after calls to noreturn functions. The unreachable warnings aren't very important anyway. Just ignore them for old versions of GCC. Reported-by: kbuild test robot <fengguang.wu@intel.com> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/bc89b807d965b98ec18a0bb94f96a594bd58f2f2.1506551639.git.jpoimboe@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-09-04Merge branch 'x86-asm-for-linus' of ↵Linus Torvalds1-4/+13
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 asm updates from Ingo Molnar: - Introduce the ORC unwinder, which can be enabled via CONFIG_ORC_UNWINDER=y. The ORC unwinder is a lightweight, Linux kernel specific debuginfo implementation, which aims to be DWARF done right for unwinding. Objtool is used to generate the ORC unwinder tables during build, so the data format is flexible and kernel internal: there's no dependency on debuginfo created by an external toolchain. The ORC unwinder is almost two orders of magnitude faster than the (out of tree) DWARF unwinder - which is important for perf call graph profiling. It is also significantly simpler and is coded defensively: there has not been a single ORC related kernel crash so far, even with early versions. (knock on wood!) But the main advantage is that enabling the ORC unwinder allows CONFIG_FRAME_POINTERS to be turned off - which speeds up the kernel measurably: With frame pointers disabled, GCC does not have to add frame pointer instrumentation code to every function in the kernel. The kernel's .text size decreases by about 3.2%, resulting in better cache utilization and fewer instructions executed, resulting in a broad kernel-wide speedup. Average speedup of system calls should be roughly in the 1-3% range - measurements by Mel Gorman [1] have shown a speedup of 5-10% for some function execution intense workloads. The main cost of the unwinder is that the unwinder data has to be stored in RAM: the memory cost is 2-4MB of RAM, depending on kernel config - which is a modest cost on modern x86 systems. Given how young the ORC unwinder code is it's not enabled by default - but given the performance advantages the plan is to eventually make it the default unwinder on x86. See Documentation/x86/orc-unwinder.txt for more details. - Remove lguest support: its intended role was that of a temporary proof of concept for virtualization, plus its removal will enable the reduction (removal) of the paravirt API as well, so Rusty agreed to its removal. (Juergen Gross) - Clean up and fix FSGS related functionality (Andy Lutomirski) - Clean up IO access APIs (Andy Shevchenko) - Enhance the symbol namespace (Jiri Slaby) * 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (47 commits) objtool: Handle GCC stack pointer adjustment bug x86/entry/64: Use ENTRY() instead of ALIGN+GLOBAL for stub32_clone() x86/fpu/math-emu: Add ENDPROC to functions x86/boot/64: Extract efi_pe_entry() from startup_64() x86/boot/32: Extract efi_pe_entry() from startup_32() x86/lguest: Remove lguest support x86/paravirt/xen: Remove xen_patch() objtool: Fix objtool fallthrough detection with function padding x86/xen/64: Fix the reported SS and CS in SYSCALL objtool: Track DRAP separately from callee-saved registers objtool: Fix validate_branch() return codes x86: Clarify/fix no-op barriers for text_poke_bp() x86/switch_to/64: Rewrite FS/GS switching yet again to fix AMD CPUs selftests/x86/fsgsbase: Test selectors 1, 2, and 3 x86/fsgsbase/64: Report FSBASE and GSBASE correctly in core dumps x86/fsgsbase/64: Fully initialize FS and GS state in start_thread_common x86/asm: Fix UNWIND_HINT_REGS macro for older binutils x86/asm/32: Fix regs_get_register() on segment registers x86/xen/64: Rearrange the SYSCALL entries x86/asm/32: Remove a bunch of '& 0xffff' from pt_regs segment reads ...
2017-08-10kbuild: trivial cleanups on the commentsCao jin1-4/+4
This is a bunch of trivial fixes and cleanups. Signed-off-by: Cao jin <caoj.fnst@cn.fujitsu.com> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2017-07-26x86/unwind: Add the ORC unwinderJosh Poimboeuf1-4/+10
Add the new ORC unwinder which is enabled by CONFIG_ORC_UNWINDER=y. It plugs into the existing x86 unwinder framework. It relies on objtool to generate the needed .orc_unwind and .orc_unwind_ip sections. For more details on why ORC is used instead of DWARF, see Documentation/x86/orc-unwinder.txt - but the short version is that it's a simplified, fundamentally more robust debugninfo data structure, which also allows up to two orders of magnitude faster lookups than the DWARF unwinder - which matters to profiling workloads like perf. Thanks to Andy Lutomirski for the performance improvement ideas: splitting the ORC unwind table into two parallel arrays and creating a fast lookup table to search a subset of the unwind table. Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Jiri Slaby <jslaby@suse.cz> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: live-patching@vger.kernel.org Link: http://lkml.kernel.org/r/0a6cbfb40f8da99b7a45a1a8302dc6aef16ec812.1500938583.git.jpoimboe@redhat.com [ Extended the changelog. ] Signed-off-by: Ingo Molnar <mingo@kernel.org>
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