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Date:   Tue, 13 Jul 2021 22:47:18 +0300
From:   Alexey Dobriyan <adobriyan@gmail.com>
To:     akpm@linux-foundation.org
Cc:     linux-kbuild@vger.kernel.org, linux-kernel@vger.kernel.org,
        linux-arch@vger.kernel.org, arnd@arndb.de
Subject: [PATCH] Decouple build from userspace headers
Message-ID: <YO3txvw87MjKfdpq@localhost.localdomain>
MIME-Version: 1.0
Content-Type: text/plain; charset=utf-8
Content-Disposition: inline
Precedence: bulk

In theory, userspace headers can be under incompatible license.

Linux by virtue of being OS kernel is fully independent piece of code
and should not require anything from userspace.

For this:

* ship minimal <stdarg.h>
	2 types, 4 macros

* delete "-isystem"
	This is what enables leakage.

* fixup compilation where necessary.

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
---

 Makefile                                                               |    2 +-
 arch/um/include/shared/irq_user.h                                      |    1 -
 arch/um/os-Linux/signal.c                                              |    2 +-
 crypto/aegis128-neon-inner.c                                           |    2 --
 drivers/net/wwan/iosm/iosm_ipc_imem.h                                  |    1 -
 drivers/pinctrl/aspeed/pinmux-aspeed.h                                 |    1 -
 drivers/staging/media/atomisp/pci/hive_isp_css_common/host/isp_local.h |    2 --
 include/stdarg.h                                                       |    9 +++++++++
 sound/aoa/codecs/onyx.h                                                |    1 -
 sound/aoa/codecs/tas.c                                                 |    1 -
 10 files changed, 11 insertions(+), 11 deletions(-)

--- a/Makefile
+++ b/Makefile
@@ -978,7 +978,7 @@ KBUILD_CFLAGS += -falign-functions=64
 endif
 
 # 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
--- a/arch/um/include/shared/irq_user.h
+++ b/arch/um/include/shared/irq_user.h
@@ -7,7 +7,6 @@
 #define __IRQ_USER_H__
 
 #include <sysdep/ptrace.h>
-#include <stdbool.h>
 
 enum um_irq_type {
 	IRQ_READ,
--- a/arch/um/os-Linux/signal.c
+++ b/arch/um/os-Linux/signal.c
@@ -67,7 +67,7 @@ int signals_enabled;
 #ifdef UML_CONFIG_UML_TIME_TRAVEL_SUPPORT
 static int signals_blocked;
 #else
-#define signals_blocked false
+#define signals_blocked 0
 #endif
 static unsigned int signals_pending;
 static unsigned int signals_active = 0;
--- a/crypto/aegis128-neon-inner.c
+++ b/crypto/aegis128-neon-inner.c
@@ -15,8 +15,6 @@
 
 #define AEGIS_BLOCK_SIZE	16
 
-#include <stddef.h>
-
 extern int aegis128_have_aes_insn;
 
 void *memcpy(void *dest, const void *src, size_t n);
--- a/drivers/net/wwan/iosm/iosm_ipc_imem.h
+++ b/drivers/net/wwan/iosm/iosm_ipc_imem.h
@@ -7,7 +7,6 @@
 #define IOSM_IPC_IMEM_H
 
 #include <linux/skbuff.h>
-#include <stdbool.h>
 
 #include "iosm_ipc_mmio.h"
 #include "iosm_ipc_pcie.h"
--- a/drivers/pinctrl/aspeed/pinmux-aspeed.h
+++ b/drivers/pinctrl/aspeed/pinmux-aspeed.h
@@ -5,7 +5,6 @@
 #define ASPEED_PINMUX_H
 
 #include <linux/regmap.h>
-#include <stdbool.h>
 
 /*
  * The ASPEED SoCs provide typically more than 200 pins for GPIO and other
--- a/drivers/staging/media/atomisp/pci/hive_isp_css_common/host/isp_local.h
+++ b/drivers/staging/media/atomisp/pci/hive_isp_css_common/host/isp_local.h
@@ -16,8 +16,6 @@
 #ifndef __ISP_LOCAL_H_INCLUDED__
 #define __ISP_LOCAL_H_INCLUDED__
 
-#include <stdbool.h>
-
 #include "isp_global.h"
 
 #include <isp2400_support.h>
new file mode 100644
--- /dev/null
+++ b/include/stdarg.h
@@ -0,0 +1,9 @@
+#ifndef _LINUX_STDARG_H
+#define _LINUX_STDARG_H
+typedef __builtin_va_list __gnuc_va_list;
+typedef __builtin_va_list va_list;
+#define va_start(v, l)	__builtin_va_start(v, l)
+#define va_end(v)	__builtin_va_end(v)
+#define va_arg(v, T)	__builtin_va_arg(v, T)
+#define va_copy(d, s)	__builtin_va_copy(d, s)
+#endif
--- a/sound/aoa/codecs/onyx.h
+++ b/sound/aoa/codecs/onyx.h
@@ -6,7 +6,6 @@
  */
 #ifndef __SND_AOA_CODEC_ONYX_H
 #define __SND_AOA_CODEC_ONYX_H
-#include <stddef.h>
 #include <linux/i2c.h>
 #include <asm/pmac_low_i2c.h>
 #include <asm/prom.h>
--- a/sound/aoa/codecs/tas.c
+++ b/sound/aoa/codecs/tas.c
@@ -58,7 +58,6 @@
  *    and up to the hardware designer to not wire
  *    them up in some weird unusable way.
  */
-#include <stddef.h>
 #include <linux/i2c.h>
 #include <asm/pmac_low_i2c.h>
 #include <asm/prom.h>