korg/linux
0
0
Fork 0
mirror of https://mirrors.bfsu.edu.cn/git/linux.git synced 2024-12-02 00:24:12 +08:00
Code Issues Packages Projects Releases Wiki Activity
1f1475f38b
linux/arch/arm64/include/asm/processor.h
Marc Zyngier cbdf8a189a arm64: Force SSBS on context switch 
On a CPU that doesn't support SSBS, PSTATE[12] is RES0.  In a system
where only some of the CPUs implement SSBS, we end-up losing track of
the SSBS bit across task migration.

To address this issue, let's force the SSBS bit on context switch.

Fixes: 8f04e8e6e2 ("arm64: ssbd: Add support for PSTATE.SSBS rather than trapping to EL3")
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
[will: inverted logic and added comments]
Signed-off-by: Will Deacon <will@kernel.org>
2019-07-22 15:24:16 +01:00

326 lines
8.5 KiB
C
Raw Blame History

/* SPDX-License-Identifier: GPL-2.0-only */
/*
* Based on arch/arm/include/asm/processor.h
*
* Copyright (C) 1995-1999 Russell King
* Copyright (C) 2012 ARM Ltd.
*/
#ifndef __ASM_PROCESSOR_H
#define __ASM_PROCESSOR_H
#define KERNEL_DS UL(-1)
#define USER_DS ((UL(1) << MAX_USER_VA_BITS) - 1)
/*
* On arm64 systems, unaligned accesses by the CPU are cheap, and so there is
* no point in shifting all network buffers by 2 bytes just to make some IP
* header fields appear aligned in memory, potentially sacrificing some DMA
* performance on some platforms.
*/
#define NET_IP_ALIGN 0
#ifndef __ASSEMBLY__
#ifdef __KERNEL__
#include <linux/build_bug.h>
#include <linux/cache.h>
#include <linux/init.h>
#include <linux/stddef.h>
#include <linux/string.h>
#include <asm/alternative.h>
#include <asm/cpufeature.h>
#include <asm/hw_breakpoint.h>
#include <asm/lse.h>
#include <asm/pgtable-hwdef.h>
#include <asm/pointer_auth.h>
#include <asm/ptrace.h>
#include <asm/types.h>
/*
* TASK_SIZE - the maximum size of a user space task.
* TASK_UNMAPPED_BASE - the lower boundary of the mmap VM area.
*/
#define DEFAULT_MAP_WINDOW_64 (UL(1) << VA_BITS)
#define TASK_SIZE_64 (UL(1) << vabits_user)
#ifdef CONFIG_COMPAT
#if defined(CONFIG_ARM64_64K_PAGES) && defined(CONFIG_KUSER_HELPERS)
/*
* With CONFIG_ARM64_64K_PAGES enabled, the last page is occupied
* by the compat vectors page.
*/
#define TASK_SIZE_32 UL(0x100000000)
#else
#define TASK_SIZE_32 (UL(0x100000000) - PAGE_SIZE)
#endif /* CONFIG_ARM64_64K_PAGES */
#define TASK_SIZE (test_thread_flag(TIF_32BIT) ? \
TASK_SIZE_32 : TASK_SIZE_64)
#define TASK_SIZE_OF(tsk) (test_tsk_thread_flag(tsk, TIF_32BIT) ? \
TASK_SIZE_32 : TASK_SIZE_64)
#define DEFAULT_MAP_WINDOW (test_thread_flag(TIF_32BIT) ? \
TASK_SIZE_32 : DEFAULT_MAP_WINDOW_64)
#else
#define TASK_SIZE TASK_SIZE_64
#define DEFAULT_MAP_WINDOW DEFAULT_MAP_WINDOW_64
#endif /* CONFIG_COMPAT */
#ifdef CONFIG_ARM64_FORCE_52BIT
#define STACK_TOP_MAX TASK_SIZE_64
#define TASK_UNMAPPED_BASE (PAGE_ALIGN(TASK_SIZE / 4))
#else
#define STACK_TOP_MAX DEFAULT_MAP_WINDOW_64
#define TASK_UNMAPPED_BASE (PAGE_ALIGN(DEFAULT_MAP_WINDOW / 4))
#endif /* CONFIG_ARM64_FORCE_52BIT */
#ifdef CONFIG_COMPAT
#define AARCH32_VECTORS_BASE 0xffff0000
#define STACK_TOP (test_thread_flag(TIF_32BIT) ? \
AARCH32_VECTORS_BASE : STACK_TOP_MAX)
#else
#define STACK_TOP STACK_TOP_MAX
#endif /* CONFIG_COMPAT */
#ifndef CONFIG_ARM64_FORCE_52BIT
#define arch_get_mmap_end(addr) ((addr > DEFAULT_MAP_WINDOW) ? TASK_SIZE :\
DEFAULT_MAP_WINDOW)
#define arch_get_mmap_base(addr, base) ((addr > DEFAULT_MAP_WINDOW) ? \
base + TASK_SIZE - DEFAULT_MAP_WINDOW :\
base)
#endif /* CONFIG_ARM64_FORCE_52BIT */
extern phys_addr_t arm64_dma_phys_limit;
#define ARCH_LOW_ADDRESS_LIMIT (arm64_dma_phys_limit - 1)
struct debug_info {
#ifdef CONFIG_HAVE_HW_BREAKPOINT
/* Have we suspended stepping by a debugger? */
int suspended_step;
/* Allow breakpoints and watchpoints to be disabled for this thread. */
int bps_disabled;
int wps_disabled;
/* Hardware breakpoints pinned to this task. */
struct perf_event *hbp_break[ARM_MAX_BRP];
struct perf_event *hbp_watch[ARM_MAX_WRP];
#endif
};
struct cpu_context {
unsigned long x19;
unsigned long x20;
unsigned long x21;
unsigned long x22;
unsigned long x23;
unsigned long x24;
unsigned long x25;
unsigned long x26;
unsigned long x27;
unsigned long x28;
unsigned long fp;
unsigned long sp;
unsigned long pc;
};
struct thread_struct {
struct cpu_context cpu_context; /* cpu context */
/*
* Whitelisted fields for hardened usercopy:
* Maintainers must ensure manually that this contains no
* implicit padding.
*/
struct {
unsigned long tp_value; /* TLS register */
unsigned long tp2_value;
struct user_fpsimd_state fpsimd_state;
} uw;
unsigned int fpsimd_cpu;
void *sve_state; /* SVE registers, if any */
unsigned int sve_vl; /* SVE vector length */
unsigned int sve_vl_onexec; /* SVE vl after next exec */
unsigned long fault_address; /* fault info */
unsigned long fault_code; /* ESR_EL1 value */
struct debug_info debug; /* debugging */
#ifdef CONFIG_ARM64_PTR_AUTH
struct ptrauth_keys keys_user;
#endif
};
static inline void arch_thread_struct_whitelist(unsigned long *offset,
unsigned long *size)
{
/* Verify that there is no padding among the whitelisted fields: */
BUILD_BUG_ON(sizeof_field(struct thread_struct, uw) !=
sizeof_field(struct thread_struct, uw.tp_value) +
sizeof_field(struct thread_struct, uw.tp2_value) +
sizeof_field(struct thread_struct, uw.fpsimd_state));
*offset = offsetof(struct thread_struct, uw);
*size = sizeof_field(struct thread_struct, uw);
}
#ifdef CONFIG_COMPAT
#define task_user_tls(t) \
({ \
unsigned long *__tls; \
if (is_compat_thread(task_thread_info(t))) \
__tls = &(t)->thread.uw.tp2_value; \
else \
__tls = &(t)->thread.uw.tp_value; \
__tls; \
})
#else
#define task_user_tls(t) (&(t)->thread.uw.tp_value)
#endif
/* Sync TPIDR_EL0 back to thread_struct for current */
void tls_preserve_current_state(void);
#define INIT_THREAD { \
.fpsimd_cpu = NR_CPUS, \
}
static inline void start_thread_common(struct pt_regs *regs, unsigned long pc)
{
memset(regs, 0, sizeof(*regs));
forget_syscall(regs);
regs->pc = pc;
if (system_uses_irq_prio_masking())
regs->pmr_save = GIC_PRIO_IRQON;
}
static inline void set_ssbs_bit(struct pt_regs *regs)
{
regs->pstate |= PSR_SSBS_BIT;
}
static inline void set_compat_ssbs_bit(struct pt_regs *regs)
{
regs->pstate |= PSR_AA32_SSBS_BIT;
}
static inline void start_thread(struct pt_regs *regs, unsigned long pc,
unsigned long sp)
{
start_thread_common(regs, pc);
regs->pstate = PSR_MODE_EL0t;
if (arm64_get_ssbd_state() != ARM64_SSBD_FORCE_ENABLE)
set_ssbs_bit(regs);
regs->sp = sp;
}
#ifdef CONFIG_COMPAT
static inline void compat_start_thread(struct pt_regs *regs, unsigned long pc,
unsigned long sp)
{
start_thread_common(regs, pc);
regs->pstate = PSR_AA32_MODE_USR;
if (pc & 1)
regs->pstate |= PSR_AA32_T_BIT;
#ifdef __AARCH64EB__
regs->pstate |= PSR_AA32_E_BIT;
#endif
if (arm64_get_ssbd_state() != ARM64_SSBD_FORCE_ENABLE)
set_compat_ssbs_bit(regs);
regs->compat_sp = sp;
}
#endif
/* Forward declaration, a strange C thing */
struct task_struct;
/* Free all resources held by a thread. */
extern void release_thread(struct task_struct *);
unsigned long get_wchan(struct task_struct *p);
static inline void cpu_relax(void)
{
asm volatile("yield" ::: "memory");
}
/* Thread switching */
extern struct task_struct *cpu_switch_to(struct task_struct *prev,
struct task_struct *next);
#define task_pt_regs(p) \
((struct pt_regs *)(THREAD_SIZE + task_stack_page(p)) - 1)
#define KSTK_EIP(tsk) ((unsigned long)task_pt_regs(tsk)->pc)
#define KSTK_ESP(tsk) user_stack_pointer(task_pt_regs(tsk))
/*
* Prefetching support
*/
#define ARCH_HAS_PREFETCH
static inline void prefetch(const void *ptr)
{
asm volatile("prfm pldl1keep, %a0\n" : : "p" (ptr));
}
#define ARCH_HAS_PREFETCHW
static inline void prefetchw(const void *ptr)
{
asm volatile("prfm pstl1keep, %a0\n" : : "p" (ptr));
}
#define ARCH_HAS_SPINLOCK_PREFETCH
static inline void spin_lock_prefetch(const void *ptr)
{
asm volatile(ARM64_LSE_ATOMIC_INSN(
"prfm pstl1strm, %a0",
"nop") : : "p" (ptr));
}
#define HAVE_ARCH_PICK_MMAP_LAYOUT
#endif
extern unsigned long __ro_after_init signal_minsigstksz; /* sigframe size */
extern void __init minsigstksz_setup(void);
/*
* Not at the top of the file due to a direct #include cycle between
* <asm/fpsimd.h> and <asm/processor.h>. Deferring this #include
* ensures that contents of processor.h are visible to fpsimd.h even if
* processor.h is included first.
*
* These prctl helpers are the only things in this file that require
* fpsimd.h. The core code expects them to be in this header.
*/
#include <asm/fpsimd.h>
/* Userspace interface for PR_SVE_{SET,GET}_VL prctl()s: */
#define SVE_SET_VL(arg) sve_set_current_vl(arg)
#define SVE_GET_VL() sve_get_current_vl()
/* PR_PAC_RESET_KEYS prctl */
#define PAC_RESET_KEYS(tsk, arg) ptrauth_prctl_reset_keys(tsk, arg)
/*
* For CONFIG_GCC_PLUGIN_STACKLEAK
*
* These need to be macros because otherwise we get stuck in a nightmare
* of header definitions for the use of task_stack_page.
*/
#define current_top_of_stack() \
({ \
struct stack_info _info; \
BUG_ON(!on_accessible_stack(current, current_stack_pointer, &_info)); \
_info.high; \
})
#define on_thread_stack() (on_task_stack(current, current_stack_pointer, NULL))
#endif /* __ASSEMBLY__ */
#endif /* __ASM_PROCESSOR_H */
Reference in New Issue View Git Blame Copy Permalink