linux/arch/arm64/include/asm/exception.h
Dave Martin 8ef8f360cf arm64: Basic Branch Target Identification support
This patch adds the bare minimum required to expose the ARMv8.5
Branch Target Identification feature to userspace.

By itself, this does _not_ automatically enable BTI for any initial
executable pages mapped by execve().  This will come later, but for
now it should be possible to enable BTI manually on those pages by
using mprotect() from within the target process.

Other arches already using the generic mman.h are already using
0x10 for arch-specific prot flags, so we use that for PROT_BTI
here.

For consistency, signal handler entry points in BTI guarded pages
are required to be annotated as such, just like any other function.
This blocks a relatively minor attack vector, but comforming
userspace will have the annotations anyway, so we may as well
enforce them.

Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Dave Martin <Dave.Martin@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2020-03-16 17:19:48 +00:00

51 lines
1.6 KiB
C

/* SPDX-License-Identifier: GPL-2.0-only */
/*
* Based on arch/arm/include/asm/exception.h
*
* Copyright (C) 2012 ARM Ltd.
*/
#ifndef __ASM_EXCEPTION_H
#define __ASM_EXCEPTION_H
#include <asm/esr.h>
#include <asm/kprobes.h>
#include <asm/ptrace.h>
#include <linux/interrupt.h>
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
#define __exception_irq_entry __irq_entry
#else
#define __exception_irq_entry __kprobes
#endif
static inline u32 disr_to_esr(u64 disr)
{
unsigned int esr = ESR_ELx_EC_SERROR << ESR_ELx_EC_SHIFT;
if ((disr & DISR_EL1_IDS) == 0)
esr |= (disr & DISR_EL1_ESR_MASK);
else
esr |= (disr & ESR_ELx_ISS_MASK);
return esr;
}
asmlinkage void enter_from_user_mode(void);
void do_mem_abort(unsigned long addr, unsigned int esr, struct pt_regs *regs);
void do_undefinstr(struct pt_regs *regs);
void do_bti(struct pt_regs *regs);
asmlinkage void bad_mode(struct pt_regs *regs, int reason, unsigned int esr);
void do_debug_exception(unsigned long addr_if_watchpoint, unsigned int esr,
struct pt_regs *regs);
void do_fpsimd_acc(unsigned int esr, struct pt_regs *regs);
void do_sve_acc(unsigned int esr, struct pt_regs *regs);
void do_fpsimd_exc(unsigned int esr, struct pt_regs *regs);
void do_sysinstr(unsigned int esr, struct pt_regs *regs);
void do_sp_pc_abort(unsigned long addr, unsigned int esr, struct pt_regs *regs);
void bad_el0_sync(struct pt_regs *regs, int reason, unsigned int esr);
void do_cp15instr(unsigned int esr, struct pt_regs *regs);
void do_el0_svc(struct pt_regs *regs);
void do_el0_svc_compat(struct pt_regs *regs);
#endif /* __ASM_EXCEPTION_H */