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Jisheng Zhang ecf78af514 riscv: vdso: fix build with llvm 
[ Upstream commit 50f4dd657a ]

Even after commit 89fd4a1df8 ("riscv: jump_label: mark arguments as
const to satisfy asm constraints"), building with CC_OPTIMIZE_FOR_SIZE
+ LLVM=1 can reproduce below build error:

  CC      arch/riscv/kernel/vdso/vgettimeofday.o
In file included from <built-in>:4:
In file included from lib/vdso/gettimeofday.c:5:
In file included from include/vdso/datapage.h:17:
In file included from include/vdso/processor.h:10:
In file included from arch/riscv/include/asm/vdso/processor.h:7:
In file included from include/linux/jump_label.h:112:
arch/riscv/include/asm/jump_label.h:42:3: error:
invalid operand for inline asm constraint 'i'
                "       .option push                            \n\t"
                ^
1 error generated.

I think the problem is when "-Os" is passed as CFLAGS, it's removed by
"CFLAGS_REMOVE_vgettimeofday.o = $(CC_FLAGS_FTRACE) -Os" which is
introduced in commit e05d57dcb8 ("riscv: Fixup __vdso_gettimeofday
broke dynamic ftrace"), thus no optimization at all for vgettimeofday.c
arm64 does remove "-Os" as well, but it forces "-O2" after removing
"-Os".

I compared the generated vgettimeofday.o with "-O2" and "-Os",
I think no big performance difference. So let's tell the kbuild not
to remove "-Os" rather than follow arm64 style.

vdso related performance can be improved a lot when building kernel with
CC_OPTIMIZE_FOR_SIZE after this commit, ("-Os" VS no optimization)

Fixes: e05d57dcb8 ("riscv: Fixup __vdso_gettimeofday broke dynamic ftrace")
Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
Tested-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://lore.kernel.org/r/20221031182943.2453-1-jszhang@kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-11-16 09:57:14 +01:00
arch riscv: vdso: fix build with llvm 2022-11-16 09:57:14 +01:00
block block, bfq: protect 'bfqd->queued' by 'bfqd->lock' 2022-11-10 18:14:24 +01:00
certs certs/blacklist_hashes.c: fix const confusion in certs blacklist 2022-06-22 14:13:17 +02:00
crypto crypto: akcipher - default implementation for setting a private key 2022-10-26 13:25:42 +02:00
Documentation KVM: s390: pv: don't allow userspace to set the clock under PV 2022-11-16 09:57:10 +01:00
drivers net: macvlan: fix memory leaks of macvlan_common_newlink 2022-11-16 09:57:14 +01:00
fs fuse: fix readdir cache race 2022-11-16 09:57:07 +01:00
include capabilities: fix undefined behavior in bit shift for CAP_TO_MASK 2022-11-16 09:57:10 +01:00
init Kconfig: Add option for asm goto w/ tied outputs to workaround clang-13 bug 2022-06-09 10:21:25 +02:00
ipc ipc: remove memcg accounting for sops objects in do_semtimedop() 2022-11-10 18:14:29 +01:00
kernel bpf: Fix wrong reg type conversion in release_reference() 2022-11-16 09:57:09 +01:00
lib dyndbg: drop EXPORTed dynamic_debug_exec_queries 2022-10-26 13:25:34 +02:00
LICENSES LICENSES/deprecated: add Zlib license text 2020-09-16 14:33:49 +02:00
mm mm,hugetlb: take hugetlb_lock before decrementing h->resv_huge_pages 2022-11-03 23:57:50 +09:00
net tipc: fix the msg->req tlv len check in tipc_nl_compat_name_table_dump_header 2022-11-16 09:57:11 +01:00
samples x86: Prepare inline-asm for straight-line-speculation 2022-07-25 11:26:29 +02:00
scripts kbuild: Add skip_encoding_btf_enum64 option to pahole 2022-10-28 12:57:12 +02:00
security capabilities: fix potential memleak on error path from vfs_getxattr_alloc() 2022-11-10 18:14:26 +01:00
sound ALSA: usb-audio: Add quirks for MacroSilicon MS2100/MS2106 devices 2022-11-10 18:14:24 +01:00
tools perf stat: Fix printing os->prefix in CSV metrics output 2022-11-16 09:57:12 +01:00
usr usr/include/Makefile: add linux/nfc.h to the compile-test coverage 2022-02-01 17:25:48 +01:00
virt kvm: Add support for arch compat vm ioctls 2022-10-30 09:41:15 +01:00
.clang-format RDMA 5.10 pull request 2020-10-17 11:18:18 -07:00
.cocciconfig
.get_maintainer.ignore
.gitattributes
.gitignore kbuild: generate Module.symvers only when vmlinux exists 2021-05-19 10:12:59 +02:00
.mailmap mailmap: add two more addresses of Uwe Kleine-König 2020-12-06 10:19:07 -08:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS MAINTAINERS: Move Jason Cooper to CREDITS 2020-11-30 10:20:34 +01:00
Kbuild kbuild: rename hostprogs-y/always to hostprogs/always-y 2020-02-04 01:53:07 +09:00
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
MAINTAINERS MAINTAINERS: add Amir as xfs maintainer for 5.10.y 2022-07-02 16:39:22 +02:00
Makefile Linux 5.10.154 2022-11-10 18:14:30 +01:00
README

README 

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.