linux/arch/arm/include/asm/domain.h
Masahiro Yamada 851140ab0d ARM: 8908/1: add __always_inline to functions called from __get_user_check()
KernelCI reports that bcm2835_defconfig is no longer booting since
commit ac7c3e4ff4 ("compiler: enable CONFIG_OPTIMIZE_INLINING
forcibly") (https://lkml.org/lkml/2019/9/26/825).

I also received a regression report from Nicolas Saenz Julienne
(https://lkml.org/lkml/2019/9/27/263).

This problem has cropped up on bcm2835_defconfig because it enables
CONFIG_CC_OPTIMIZE_FOR_SIZE. The compiler tends to prefer not inlining
functions with -Os. I was able to reproduce it with other boards and
defconfig files by manually enabling CONFIG_CC_OPTIMIZE_FOR_SIZE.

The __get_user_check() specifically uses r0, r1, r2 registers.
So, uaccess_save_and_enable() and uaccess_restore() must be inlined.
Otherwise, those register assignments would be entirely dropped,
according to my analysis of the disassembly.

Prior to commit 9012d01166 ("compiler: allow all arches to enable
CONFIG_OPTIMIZE_INLINING"), the 'inline' marker was always enough for
inlining functions, except on x86.

Since that commit, all architectures can enable CONFIG_OPTIMIZE_INLINING.
So, __always_inline is now the only guaranteed way of forcible inlining.

I added __always_inline to 4 functions in the call-graph from the
__get_user_check() macro.

Fixes: 9012d01166 ("compiler: allow all arches to enable CONFIG_OPTIMIZE_INLINING")
Reported-by: "kernelci.org bot" <bot@kernelci.org>
Reported-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Tested-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
2019-10-10 22:23:19 +01:00

155 lines
3.7 KiB
C

/* SPDX-License-Identifier: GPL-2.0-only */
/*
* arch/arm/include/asm/domain.h
*
* Copyright (C) 1999 Russell King.
*/
#ifndef __ASM_PROC_DOMAIN_H
#define __ASM_PROC_DOMAIN_H
#ifndef __ASSEMBLY__
#include <asm/barrier.h>
#include <asm/thread_info.h>
#endif
/*
* Domain numbers
*
* DOMAIN_IO - domain 2 includes all IO only
* DOMAIN_USER - domain 1 includes all user memory only
* DOMAIN_KERNEL - domain 0 includes all kernel memory only
*
* The domain numbering depends on whether we support 36 physical
* address for I/O or not. Addresses above the 32 bit boundary can
* only be mapped using supersections and supersections can only
* be set for domain 0. We could just default to DOMAIN_IO as zero,
* but there may be systems with supersection support and no 36-bit
* addressing. In such cases, we want to map system memory with
* supersections to reduce TLB misses and footprint.
*
* 36-bit addressing and supersections are only available on
* CPUs based on ARMv6+ or the Intel XSC3 core.
*/
#ifndef CONFIG_IO_36
#define DOMAIN_KERNEL 0
#define DOMAIN_USER 1
#define DOMAIN_IO 2
#else
#define DOMAIN_KERNEL 2
#define DOMAIN_USER 1
#define DOMAIN_IO 0
#endif
#define DOMAIN_VECTORS 3
/*
* Domain types
*/
#define DOMAIN_NOACCESS 0
#define DOMAIN_CLIENT 1
#ifdef CONFIG_CPU_USE_DOMAINS
#define DOMAIN_MANAGER 3
#else
#define DOMAIN_MANAGER 1
#endif
#define domain_mask(dom) ((3) << (2 * (dom)))
#define domain_val(dom,type) ((type) << (2 * (dom)))
#ifdef CONFIG_CPU_SW_DOMAIN_PAN
#define DACR_INIT \
(domain_val(DOMAIN_USER, DOMAIN_NOACCESS) | \
domain_val(DOMAIN_KERNEL, DOMAIN_MANAGER) | \
domain_val(DOMAIN_IO, DOMAIN_CLIENT) | \
domain_val(DOMAIN_VECTORS, DOMAIN_CLIENT))
#else
#define DACR_INIT \
(domain_val(DOMAIN_USER, DOMAIN_CLIENT) | \
domain_val(DOMAIN_KERNEL, DOMAIN_MANAGER) | \
domain_val(DOMAIN_IO, DOMAIN_CLIENT) | \
domain_val(DOMAIN_VECTORS, DOMAIN_CLIENT))
#endif
#define __DACR_DEFAULT \
domain_val(DOMAIN_KERNEL, DOMAIN_CLIENT) | \
domain_val(DOMAIN_IO, DOMAIN_CLIENT) | \
domain_val(DOMAIN_VECTORS, DOMAIN_CLIENT)
#define DACR_UACCESS_DISABLE \
(__DACR_DEFAULT | domain_val(DOMAIN_USER, DOMAIN_NOACCESS))
#define DACR_UACCESS_ENABLE \
(__DACR_DEFAULT | domain_val(DOMAIN_USER, DOMAIN_CLIENT))
#ifndef __ASSEMBLY__
#ifdef CONFIG_CPU_CP15_MMU
static __always_inline unsigned int get_domain(void)
{
unsigned int domain;
asm(
"mrc p15, 0, %0, c3, c0 @ get domain"
: "=r" (domain)
: "m" (current_thread_info()->cpu_domain));
return domain;
}
static __always_inline void set_domain(unsigned int val)
{
asm volatile(
"mcr p15, 0, %0, c3, c0 @ set domain"
: : "r" (val) : "memory");
isb();
}
#else
static __always_inline unsigned int get_domain(void)
{
return 0;
}
static __always_inline void set_domain(unsigned int val)
{
}
#endif
#ifdef CONFIG_CPU_USE_DOMAINS
#define modify_domain(dom,type) \
do { \
unsigned int domain = get_domain(); \
domain &= ~domain_mask(dom); \
domain = domain | domain_val(dom, type); \
set_domain(domain); \
} while (0)
#else
static inline void modify_domain(unsigned dom, unsigned type) { }
#endif
/*
* Generate the T (user) versions of the LDR/STR and related
* instructions (inline assembly)
*/
#ifdef CONFIG_CPU_USE_DOMAINS
#define TUSER(instr) TUSERCOND(instr, )
#define TUSERCOND(instr, cond) #instr "t" #cond
#else
#define TUSER(instr) TUSERCOND(instr, )
#define TUSERCOND(instr, cond) #instr #cond
#endif
#else /* __ASSEMBLY__ */
/*
* Generate the T (user) versions of the LDR/STR and related
* instructions
*/
#ifdef CONFIG_CPU_USE_DOMAINS
#define TUSER(instr) instr ## t
#else
#define TUSER(instr) instr
#endif
#endif /* __ASSEMBLY__ */
#endif /* !__ASM_PROC_DOMAIN_H */