linux/scripts/mod, branch v4.20

Revert "kbuild/Makefile: Prepare for using macros in inline assembly code to work around asm() related GCC inlining bugs"

2018-12-19T11:00:28Z

This reverts commit 77b0bf55bc675233d22cd5df97605d516d64525e. See this commit for details about the revert: e769742d3584 ("Revert "x86/jump-labels: Macrofy inline assembly code to work around GCC inlining bugs"") Conflicts: arch/x86/Makefile Reported-by: Masahiro Yamada Reviewed-by: Borislav Petkov Reviewed-by: Thomas Gleixner Cc: Juergen Gross Cc: Richard Biener Cc: Kees Cook Cc: Segher Boessenkool Cc: Ard Biesheuvel Cc: Peter Zijlstra Cc: Josh Poimboeuf Cc: Nadav Amit Cc: Linus Torvalds Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar

Merge tag 'kbuild-v4.20' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

2018-10-28T20:22:35Z

Pull Kbuild updates from Masahiro Yamada: - optimize kallsyms slightly - remove check for old CFLAGS usage - add some compiler flags unconditionally instead of evaluating $(call cc-option,...) - fix variable shadowing in host tools - refactor scripts/mkmakefile - refactor various makefiles * tag 'kbuild-v4.20' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: modpost: Create macro to avoid variable shadowing ASN.1: Remove unnecessary shadowed local variable kbuild: use 'else ifeq' for checksrc to improve readability kbuild: remove unneeded link_multi_deps kbuild: add -Wno-unused-but-set-variable flag unconditionally kbuild: add -Wdeclaration-after-statement flag unconditionally kbuild: add -Wno-pointer-sign flag unconditionally modpost: remove leftover symbol prefix handling for module device table kbuild: simplify command line creation in scripts/mkmakefile kbuild: do not pass $(objtree) to scripts/mkmakefile kbuild: remove user ID check in scripts/mkmakefile kbuild: remove VERSION and PATCHLEVEL from $(objtree)/Makefile kbuild: add --include-dir flag only for out-of-tree build kbuild: remove dead code in cmd_files calculation in top Makefile kbuild: hide most of targets when running config or mixed targets kbuild: remove old check for CFLAGS use kbuild: prefix Makefile.dtbinst path with $(srctree) unconditionally kallsyms: remove left-over Blackfin code kallsyms: reduce size a little on 64-bit

modpost: Create macro to avoid variable shadowing

2018-10-28T15:41:41Z

Create DEF_FIELD_ADDR_VAR as a more generic version of the DEF_FIELD_ADD macro, allowing usage of a variable name other than the struct element name. Also, sets DEF_FIELD_ADDR as a specific usage of DEF_FILD_ADDR_VAR in which the var name is the same as the struct element name. Then, makes use of DEF_FIELD_ADDR_VAR to create a variable of another name, in order to avoid variable shadowing. Signed-off-by: Leonardo Bras Signed-off-by: Masahiro Yamada

modpost: remove leftover symbol prefix handling for module device table

2018-10-19T00:47:44Z

Blackfin and metag were the only architectures that prefix symbols with an underscore. They were removed by commit 4ba66a976072 ("arch: remove blackfin port"), commit bb6fb6dfcc17 ("metag: Remove arch/metag/"), respectively. It is no longer necessary to handle part of module device table symbols. Signed-off-by: Masahiro Yamada

kbuild/Makefile: Prepare for using macros in inline assembly code to work around asm() related GCC inlining bugs

2018-10-04T08:57:09Z

Using macros in inline assembly allows us to work around bugs in GCC's inlining decisions. Compile macros.S and use it to assemble all C files. Currently only x86 will use it. Background: The inlining pass of GCC doesn't include an assembler, so it's not aware of basic properties of the generated code, such as its size in bytes, or that there are such things as discontiuous blocks of code and data due to the newfangled linker feature called 'sections' ... Instead GCC uses a lazy and fragile heuristic: it does a linear count of certain syntactic and whitespace elements in inlined assembly block source code, such as a count of new-lines and semicolons (!), as a poor substitute for "code size and complexity". Unsurprisingly this heuristic falls over and breaks its neck whith certain common types of kernel code that use inline assembly, such as the frequent practice of putting useful information into alternative sections. As a result of this fresh, 20+ years old GCC bug, GCC's inlining decisions are effectively disabled for inlined functions that make use of such asm() blocks, because GCC thinks those sections of code are "large" - when in reality they are often result in just a very low number of machine instructions. This absolute lack of inlining provess when GCC comes across such asm() blocks both increases generated kernel code size and causes performance overhead, which is particularly noticeable on paravirt kernels, which make frequent use of these inlining facilities in attempt to stay out of the way when running on baremetal hardware. Instead of fixing the compiler we use a workaround: we set an assembly macro and call it from the inlined assembly block. As a result GCC considers the inline assembly block as a single instruction. (Which it often isn't but I digress.) This uglifies and bloats the source code - for example just the refcount related changes have this impact: Makefile | 9 +++++++-- arch/x86/Makefile | 7 +++++++ arch/x86/kernel/macros.S | 7 +++++++ scripts/Kbuild.include | 4 +++- scripts/mod/Makefile | 2 ++ 5 files changed, 26 insertions(+), 3 deletions(-) Yay readability and maintainability, it's not like assembly code is hard to read and maintain ... We also hope that GCC will eventually get fixed, but we are not holding our breath for that. Yet we are optimistic, it might still happen, any decade now. [ mingo: Wrote new changelog describing the background. ] Tested-by: Kees Cook Signed-off-by: Nadav Amit Acked-by: Masahiro Yamada Acked-by: Peter Zijlstra (Intel) Cc: Andy Lutomirski Cc: Borislav Petkov Cc: Brian Gerst Cc: Denys Vlasenko Cc: H. Peter Anvin Cc: Linus Torvalds Cc: Michal Marek Cc: Peter Zijlstra Cc: Sam Ravnborg Cc: Thomas Gleixner Cc: linux-kbuild@vger.kernel.org Link: http://lkml.kernel.org/r/20181003213100.189959-3-namit@vmware.com Signed-off-by: Ingo Molnar

scripts: modpost: check memory allocation results

2018-08-22T14:21:40Z

Fix missing error check for memory allocation functions in scripts/mod/modpost.c. Fixes kernel bugzilla #200319: https://bugzilla.kernel.org/show_bug.cgi?id=200319 Signed-off-by: Randy Dunlap Cc: Yuexing Wang Signed-off-by: Masahiro Yamada

Merge tag 'usb-4.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb

2018-08-18T17:21:49Z

Pull USB/PHY updates from Greg KH: "Here is the big USB and phy driver patch set for 4.19-rc1. Nothing huge but there was a lot of work that happened this development cycle: - lots of type-c work, with drivers graduating out of staging, and displayport support being added. - new PHY drivers - the normal collection of gadget driver updates and fixes - code churn to work on the urb handling path, using irqsave() everywhere in anticipation of making this codepath a lot simpler in the future. - usbserial driver fixes and reworks - other misc changes All of these have been in linux-next with no reported issues for a while" * tag 'usb-4.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb: (159 commits) USB: serial: pl2303: add a new device id for ATEN usb: renesas_usbhs: Kconfig: convert to SPDX identifiers usb: dwc3: gadget: Check MaxPacketSize from descriptor usb: dwc2: Turn on uframe_sched on "stm32f4x9_fsotg" platforms usb: dwc2: Turn on uframe_sched on "amlogic" platforms usb: dwc2: Turn on uframe_sched on "his" platforms usb: dwc2: Turn on uframe_sched on "bcm" platforms usb: dwc2: gadget: ISOC's starting flow improvement usb: dwc2: Make dwc2_readl/writel functions endianness-agnostic. usb: dwc3: core: Enable AutoRetry feature in the controller usb: dwc3: Set default mode for dwc_usb31 usb: gadget: udc: renesas_usb3: Add register of usb role switch usb: dwc2: replace ioread32/iowrite32_rep with dwc2_readl/writel_rep usb: dwc2: Modify dwc2_readl/writel functions prototype usb: dwc3: pci: Intel Merrifield can be host usb: dwc3: pci: Supply device properties via driver data arm64: dts: dwc3: description of incr burst type usb: dwc3: Enable undefined length INCR burst type usb: dwc3: add global soc bus configuration reg0 usb: dwc3: Describe 'wakeup_work' field of struct dwc3_pci ...

kbuild: Add build salt to the kernel and modules

2018-07-17T16:18:05Z

In Fedora, the debug information is packaged separately (foo-debuginfo) and can be installed separately. There's been a long standing issue where only one version of a debuginfo info package can be installed at a time. There's been an effort for Fedora for parallel debuginfo to rectify this problem. Part of the requirement to allow parallel debuginfo to work is that build ids are unique between builds. The existing upstream rpm implementation ensures this by re-calculating the build-id using the version and release as a seed. This doesn't work 100% for the kernel because of the vDSO which is its own binary and doesn't get updated when embedded. Fix this by adding some data in an ELF note for both the kernel and modules. The data is controlled via a Kconfig option so distributions can set it to an appropriate value to ensure uniqueness between builds. Suggested-by: Masahiro Yamada Signed-off-by: Laura Abbott Signed-off-by: Masahiro Yamada

usb: typec: Bus type for alternate modes

2018-07-02T15:42:36Z

Introducing a simple bus for the alternate modes. Bus allows binding drivers to the discovered alternate modes the partners support. Signed-off-by: Heikki Krogerus Tested-by: Hans de Goede Signed-off-by: Greg Kroah-Hartman

Merge tag 'kbuild-v4.18' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

2018-06-06T18:00:15Z

Pull Kbuild updates from Masahiro Yamada: - improve fixdep to coalesce consecutive slashes in dep-files - fix some issues of the maintainer string generation in deb-pkg script - remove unused CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX and clean-up several tools and linker scripts - clean-up modpost - allow to enable the dead code/data elimination for PowerPC in EXPERT mode - improve two coccinelle scripts for better performance - pass endianness and machine size flags to sparse for all architecture - misc fixes * tag 'kbuild-v4.18' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (25 commits) kbuild: add machine size to CHECKFLAGS kbuild: add endianness flag to CHEKCFLAGS kbuild: $(CHECK) doesnt need NOSTDINC_FLAGS twice scripts: Fixed printf format mismatch scripts/tags.sh: use `find` for $ALLSOURCE_ARCHS generation coccinelle: deref_null: improve performance coccinelle: mini_lock: improve performance powerpc: Allow LD_DEAD_CODE_DATA_ELIMINATION to be selected kbuild: Allow LD_DEAD_CODE_DATA_ELIMINATION to be selectable if enabled kbuild: LD_DEAD_CODE_DATA_ELIMINATION no -ffunction-sections/-fdata-sections for module build kbuild: Fix asm-generic/vmlinux.lds.h for LD_DEAD_CODE_DATA_ELIMINATION modpost: constify *modname function argument where possible modpost: remove redundant is_vmlinux() test modpost: use strstarts() helper more widely modpost: pass struct elf_info pointer to get_modinfo() checkpatch: remove VMLINUX_SYMBOL() check vmlinux.lds.h: remove no-op macro VMLINUX_SYMBOL() kbuild: remove CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX export.h: remove code for prefixing symbols with underscore depmod.sh: remove symbol prefix support ...