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From: Alexey Dobriyan <>
Cc:,,, Alexey Dobriyan <>,
	Catalin Marinas <>,
	Will Deacon <>,,
	Michael Ellerman <>,
	Benjamin Herrenschmidt <>,
	Paul Mackerras <>,
Subject: [PATCH 3/3] isystem: delete global -isystem compile option
Date: Sun,  1 Aug 2021 23:13:36 +0300	[thread overview]
Message-ID: <> (raw)
In-Reply-To: <>

In theory, it enables "leakage" of userspace headers into kernel which
may present licensing problem.

In practice, only stdarg.h was used, stdbool.h is trivial and SIMD
intrinsics are contained to a few architectures and aren't global

In general, kernel is very self contained code and -isystem removal
will further isolate it from Ring Threeland influence.

nds32 keeps -isystem globally due to intrisics used in entrenched header.

-isystem is selectively reenabled for some files.

Not compile tested on hexagon.

Compile tested on:

alpha-allmodconfig alpha-allnoconfig alpha-defconfig arm64-allmodconfig
arm64-allnoconfig arm64-defconfig arm-am200epdkit arm-aspeed_g4
arm-aspeed_g5 arm-assabet arm-at91_dt arm-axm55xx arm-badge4 arm-bcm2835
arm-cerfcube arm-clps711x arm-cm_x300 arm-cns3420vb arm-colibri_pxa270
arm-colibri_pxa300 arm-collie arm-corgi arm-davinci_all arm-dove
arm-ep93xx arm-eseries_pxa arm-exynos arm-ezx arm-footbridge arm-gemini
arm-h3600 arm-h5000 arm-hackkit arm-hisi arm-imote2 arm-imx_v4_v5
arm-imx_v6_v7 arm-integrator arm-iop32x arm-ixp4xx arm-jornada720
arm-keystone arm-lart arm-lpc18xx arm-lpc32xx arm-lpd270 arm-lubbock
arm-magician arm-mainstone arm-milbeaut_m10v arm-mini2440 arm-mmp2
arm-moxart arm-mps2 arm-multi_v4t arm-multi_v5 arm-multi_v7 arm-mv78xx0
arm-mvebu_v5 arm-mvebu_v7 arm-mxs arm-neponset arm-netwinder arm-nhk8815
arm-omap1 arm-omap2plus arm-orion5x arm-oxnas_v6 arm-palmz72 arm-pcm027
arm-pleb arm-pxa arm-pxa168 arm-pxa255-idp arm-pxa3xx arm-pxa910
arm-qcom arm-realview arm-rpc arm-s3c2410 arm-s3c6400 arm-s5pv210
arm-sama5 arm-shannon arm-shmobile arm-simpad arm-socfpga arm-spear13xx
arm-spear3xx arm-spear6xx arm-spitz arm-stm32 arm-sunxi arm-tct_hammer
arm-tegra arm-trizeps4 arm-u8500 arm-versatile arm-vexpress arm-vf610m4
arm-viper arm-vt8500_v6_v7 arm-xcep arm-zeus csky-allmodconfig
csky-allnoconfig csky-defconfig h8300-edosk2674 h8300-h8300h-sim
h8300-h8s-sim i386-allmodconfig i386-allnoconfig i386-defconfig
ia64-allmodconfig ia64-allnoconfig ia64-bigsur ia64-generic ia64-gensparse
ia64-tiger ia64-zx1 m68k-amcore m68k-amiga m68k-apollo m68k-atari
m68k-bvme6000 m68k-hp300 m68k-m5208evb m68k-m5249evb m68k-m5272c3
m68k-m5275evb m68k-m5307c3 m68k-m5407c3 m68k-m5475evb m68k-mac
m68k-multi m68k-mvme147 m68k-mvme16x m68k-q40 m68k-stmark2 m68k-sun3
m68k-sun3x microblaze-allmodconfig microblaze-allnoconfig microblaze-mmu
mips-ar7 mips-ath25 mips-ath79 mips-bcm47xx mips-bcm63xx mips-bigsur
mips-bmips_be mips-bmips_stb mips-capcella mips-cavium_octeon mips-ci20
mips-cobalt mips-cu1000-neo mips-cu1830-neo mips-db1xxx mips-decstation
mips-decstation_64 mips-decstation_r4k mips-e55 mips-fuloong2e
mips-gcw0 mips-generic mips-gpr mips-ip22 mips-ip27 mips-ip28 mips-ip32
mips-jazz mips-jmr3927 mips-lemote2f mips-loongson1b mips-loongson1c
mips-loongson2k mips-loongson3 mips-malta mips-maltaaprp mips-malta_kvm
mips-malta_qemu_32r6 mips-maltasmvp mips-maltasmvp_eva mips-maltaup
mips-maltaup_xpa mips-mpc30x mips-mtx1 mips-nlm_xlp mips-nlm_xlr
mips-omega2p mips-pic32mzda mips-pistachio mips-qi_lb60 mips-rb532
mips-rbtx49xx mips-rm200 mips-rs90 mips-rt305x mips-sb1250_swarm
mips-tb0219 mips-tb0226 mips-tb0287 mips-vocore2 mips-workpad mips-xway
nds32-allmodconfig nds32-allnoconfig nds32-defconfig nios2-10m50
nios2-3c120 nios2-allmodconfig nios2-allnoconfig openrisc-allmodconfig
openrisc-allnoconfig openrisc-or1klitex openrisc-or1ksim
openrisc-simple_smp parisc-allnoconfig parisc-generic-32bit
parisc-generic-64bit powerpc-acadia powerpc-adder875 powerpc-akebono
powerpc-amigaone powerpc-arches powerpc-asp8347 powerpc-bamboo
powerpc-bluestone powerpc-canyonlands powerpc-cell powerpc-chrp32
powerpc-cm5200 powerpc-currituck powerpc-ebony powerpc-eiger
powerpc-ep8248e powerpc-ep88xc powerpc-fsp2 powerpc-g5 powerpc-gamecube
powerpc-ge_imp3a powerpc-holly powerpc-icon powerpc-iss476-smp
powerpc-katmai powerpc-kilauea powerpc-klondike powerpc-kmeter1
powerpc-ksi8560 powerpc-linkstation powerpc-lite5200b powerpc-makalu
powerpc-maple powerpc-mgcoge powerpc-microwatt powerpc-motionpro
powerpc-mpc512x powerpc-mpc5200 powerpc-mpc7448_hpc2 powerpc-mpc8272_ads
powerpc-mpc8313_rdb powerpc-mpc8315_rdb powerpc-mpc832x_mds
powerpc-mpc832x_rdb powerpc-mpc834x_itx powerpc-mpc834x_itxgp
powerpc-mpc834x_mds powerpc-mpc836x_mds powerpc-mpc836x_rdk
powerpc-mpc837x_mds powerpc-mpc837x_rdb powerpc-mpc83xx
powerpc-mpc8540_ads powerpc-mpc8560_ads powerpc-mpc85xx_cds
powerpc-mpc866_ads powerpc-mpc885_ads powerpc-mvme5100 powerpc-obs600
powerpc-pasemi powerpc-pcm030 powerpc-pmac32 powerpc-powernv
powerpc-ppa8548 powerpc-ppc40x powerpc-ppc44x powerpc-ppc64
powerpc-ppc64e powerpc-ppc6xx powerpc-pq2fads powerpc-ps3
powerpc-pseries powerpc-rainier powerpc-redwood powerpc-sam440ep
powerpc-sbc8548 powerpc-sequoia powerpc-skiroot powerpc-socrates
powerpc-storcenter powerpc-stx_gp3 powerpc-taishan powerpc-tqm5200
powerpc-tqm8540 powerpc-tqm8541 powerpc-tqm8548 powerpc-tqm8555
powerpc-tqm8560 powerpc-tqm8xx powerpc-walnut powerpc-warp powerpc-wii
powerpc-xes_mpc85xx riscv-allmodconfig riscv-allnoconfig riscv-nommu_k210
riscv-nommu_k210_sdcard riscv-nommu_virt riscv-rv32 s390-allmodconfig
s390-allnoconfig s390-debug s390-zfcpdump sh-ap325rxa sh-apsh4a3a
sh-apsh4ad0a sh-dreamcast sh-ecovec24 sh-ecovec24-romimage sh-edosk7705
sh-edosk7760 sh-espt sh-hp6xx sh-j2 sh-kfr2r09 sh-kfr2r09-romimage
sh-landisk sh-lboxre2 sh-magicpanelr2 sh-microdev sh-migor sh-polaris
sh-r7780mp sh-r7785rp sh-rsk7201 sh-rsk7203 sh-rsk7264 sh-rsk7269
sh-rts7751r2d1 sh-rts7751r2dplus sh-sdk7780 sh-sdk7786 sh-se7206 sh-se7343
sh-se7619 sh-se7705 sh-se7712 sh-se7721 sh-se7722 sh-se7724 sh-se7750
sh-se7751 sh-se7780 sh-secureedge5410 sh-sh03 sh-sh2007 sh-sh7710voipgw
sh-sh7724_generic sh-sh7757lcr sh-sh7763rdp sh-sh7770_generic sh-sh7785lcr
sh-sh7785lcr_32bit sh-shmin sh-shx3 sh-titan sh-ul2 sh-urquell
sparc-allmodconfig sparc-allnoconfig sparc-sparc32 sparc-sparc64
um-i386-allmodconfig um-i386-allnoconfig um-i386-defconfig
um-x86_64-allmodconfig um-x86_64-allnoconfig x86_64-allmodconfig
x86_64-allnoconfig x86_64-defconfig xtensa-allmodconfig xtensa-allnoconfig
xtensa-audio_kc705 xtensa-cadence_csp xtensa-common xtensa-generic_kc705
xtensa-iss xtensa-nommu_kc705 xtensa-smp_lx200 xtensa-virt

Cc: Catalin Marinas <>
Cc: Will Deacon <>
Cc: Michael Ellerman <>
Cc: Benjamin Herrenschmidt <>
Cc: Paul Mackerras <>
Signed-off-by: Alexey Dobriyan <>
 Makefile                  | 2 +-
 arch/arm64/lib/Makefile   | 2 ++
 arch/nds32/Makefile       | 2 ++
 arch/powerpc/lib/Makefile | 2 ++
 crypto/Makefile           | 2 ++
 lib/raid6/Makefile        | 4 ++++
 6 files changed, 13 insertions(+), 1 deletion(-)

diff --git a/Makefile b/Makefile
index 6b555f64df06..b59053ec457a 100644
--- a/Makefile
+++ b/Makefile
@@ -979,7 +979,7 @@ KBUILD_CFLAGS += -falign-functions=64
 # arch Makefile may override CC so keep this after arch Makefile is included
-NOSTDINC_FLAGS += -nostdinc -isystem $(shell $(CC) -print-file-name=include)
+NOSTDINC_FLAGS += -nostdinc
 # warn about C99 declaration after statement
 KBUILD_CFLAGS += -Wdeclaration-after-statement
diff --git a/arch/arm64/lib/Makefile b/arch/arm64/lib/Makefile
index 6dd56a49790a..dcad998f12d7 100644
--- a/arch/arm64/lib/Makefile
+++ b/arch/arm64/lib/Makefile
@@ -9,6 +9,8 @@ ifeq ($(CONFIG_KERNEL_MODE_NEON), y)
 obj-$(CONFIG_XOR_BLOCKS)	+= xor-neon.o
 CFLAGS_REMOVE_xor-neon.o	+= -mgeneral-regs-only
 CFLAGS_xor-neon.o		+= -ffreestanding
+# Enable <arm_neon.h>
+CFLAGS_xor-neon.o		+= -isystem $(shell $(CC) -print-file-name=include)
 lib-$(CONFIG_ARCH_HAS_UACCESS_FLUSHCACHE) += uaccess_flushcache.o
diff --git a/arch/nds32/Makefile b/arch/nds32/Makefile
index ccdca7142020..c17fc3a755c3 100644
--- a/arch/nds32/Makefile
+++ b/arch/nds32/Makefile
@@ -9,6 +9,8 @@ endif
 # Avoid generating FPU instructions
 arch-y  += -mno-ext-fpu-sp -mno-ext-fpu-dp -mfloat-abi=soft
+# Enable <nds32_intrinsic.h>
+KBUILD_CFLAGS	+= -isystem $(shell $(CC) -print-file-name=include)
 KBUILD_CFLAGS	+= $(call cc-option, -mno-sched-prolog-epilog)
 KBUILD_CFLAGS	+= -mcmodel=large
diff --git a/arch/powerpc/lib/Makefile b/arch/powerpc/lib/Makefile
index 99a7c9132422..9e5d0f413b71 100644
--- a/arch/powerpc/lib/Makefile
+++ b/arch/powerpc/lib/Makefile
@@ -65,5 +65,7 @@ obj-$(CONFIG_FTR_FIXUP_SELFTEST) += feature-fixups-test.o
 obj-$(CONFIG_ALTIVEC)	+= xor_vmx.o xor_vmx_glue.o
 CFLAGS_xor_vmx.o += -maltivec $(call cc-option,-mabi=altivec)
+# Enable <altivec.h>
+CFLAGS_xor_vmx.o += -isystem $(shell $(CC) -print-file-name=include)
 obj-$(CONFIG_PPC64) += $(obj64-y)
diff --git a/crypto/Makefile b/crypto/Makefile
index 10526d4559b8..75ad9b040506 100644
--- a/crypto/Makefile
+++ b/crypto/Makefile
@@ -117,6 +117,8 @@ aegis128-cflags-$(CONFIG_CC_IS_GCC) += -ffixed-q16 -ffixed-q17 -ffixed-q18 \
 				       -ffixed-q28 -ffixed-q29 -ffixed-q30 \
 CFLAGS_aegis128-neon-inner.o += $(aegis128-cflags-y)
+# Enable <arm_neon.h>
+CFLAGS_aegis128-neon-inner.o += -isystem $(shell $(CC) -print-file-name=include)
 CFLAGS_REMOVE_aegis128-neon-inner.o += -mgeneral-regs-only
 aegis128-$(CONFIG_CRYPTO_AEGIS128_SIMD) += aegis128-neon.o aegis128-neon-inner.o
diff --git a/lib/raid6/Makefile b/lib/raid6/Makefile
index c770570bfe4f..45e17619422b 100644
--- a/lib/raid6/Makefile
+++ b/lib/raid6/Makefile
@@ -14,6 +14,8 @@ hostprogs	+= mktables
 ifeq ($(CONFIG_ALTIVEC),y)
 altivec_flags := -maltivec $(call cc-option,-mabi=altivec)
+# Enable <altivec.h>
+altivec_flags += -isystem $(shell $(CC) -print-file-name=include)
 # clang ppc port does not yet support -maltivec when -msoft-float is
@@ -34,6 +36,8 @@ endif
 # ARM/NEON intrinsics in a non C99-compliant environment (such as the kernel)
 NEON_FLAGS := -ffreestanding
+# Enable <arm_neon.h>
+NEON_FLAGS += -isystem $(shell $(CC) -print-file-name=include)
 ifeq ($(ARCH),arm)
 NEON_FLAGS += -march=armv7-a -mfloat-abi=softfp -mfpu=neon

  parent reply	other threads:[~2021-08-01 20:14 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-08-01 20:13 [PATCH 1/3] isystem: trim/fixup stdarg.h and other headers Alexey Dobriyan
2021-08-01 20:13 ` [PATCH 2/3] isystem: ship and use stdarg.h Alexey Dobriyan
2021-08-03  7:14   ` Ard Biesheuvel
2021-08-17  1:30     ` Masahiro Yamada
2021-08-06 13:00   ` Rafael J. Wysocki
2021-08-01 20:13 ` Alexey Dobriyan [this message]
2021-08-01 21:32   ` [PATCH 3/3] isystem: delete global -isystem compile option Segher Boessenkool
2021-08-02  6:42     ` Alexey Dobriyan
2021-08-02 16:47       ` Segher Boessenkool
2021-08-02 20:30         ` Alexey Dobriyan
2021-08-02 21:42           ` Segher Boessenkool
2021-08-02  1:30   ` kernel test robot
2021-08-02 18:18   ` Nathan Chancellor
2021-08-02 20:32     ` Alexey Dobriyan
2021-08-02 20:38       ` Nathan Chancellor
2021-08-02  0:21 ` [PATCH 1/3] isystem: trim/fixup stdarg.h and other headers kernel test robot

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