From 60ffc30d5652810dd34ea2eec41504222f5d5791 Mon Sep 17 00:00:00 2001 From: Catalin Marinas Date: Mon, 5 Mar 2012 11:49:27 +0000 Subject: arm64: Exception handling The patch contains the exception entry code (kernel/entry.S), pt_regs structure and related accessors, undefined instruction trapping and stack tracing. AArch64 Linux kernel (including kernel threads) runs in EL1 mode using the SP1 stack. The vectors don't have a fixed address, only alignment (2^11) requirements. Signed-off-by: Will Deacon Signed-off-by: Catalin Marinas Acked-by: Tony Lindgren Acked-by: Nicolas Pitre Acked-by: Olof Johansson Acked-by: Santosh Shilimkar Acked-by: Arnd Bergmann --- arch/arm64/include/asm/ptrace.h | 212 ++++++++++++++++++++++++++++++++++++ arch/arm64/include/asm/stacktrace.h | 29 +++++ arch/arm64/include/asm/traps.h | 30 +++++ 3 files changed, 271 insertions(+) create mode 100644 arch/arm64/include/asm/ptrace.h create mode 100644 arch/arm64/include/asm/stacktrace.h create mode 100644 arch/arm64/include/asm/traps.h (limited to 'arch/arm64/include') diff --git a/arch/arm64/include/asm/ptrace.h b/arch/arm64/include/asm/ptrace.h new file mode 100644 index 00000000000..b0a2e1f441f --- /dev/null +++ b/arch/arm64/include/asm/ptrace.h @@ -0,0 +1,212 @@ +/* + * Based on arch/arm/include/asm/ptrace.h + * + * Copyright (C) 1996-2003 Russell King + * Copyright (C) 2012 ARM Ltd. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see . + */ +#ifndef __ASM_PTRACE_H +#define __ASM_PTRACE_H + +#include + +#include + +#define PTRACE_GETREGS 12 +#define PTRACE_SETREGS 13 +#define PTRACE_GETFPSIMDREGS 14 +#define PTRACE_SETFPSIMDREGS 15 +/* PTRACE_ATTACH is 16 */ +/* PTRACE_DETACH is 17 */ +#define PTRACE_GET_THREAD_AREA 22 +#define PTRACE_SET_SYSCALL 23 +#define PTRACE_GETHBPREGS 29 +#define PTRACE_SETHBPREGS 30 + +/* AArch32-specific ptrace requests */ +#define COMPAT_PTRACE_GETVFPREGS 27 +#define COMPAT_PTRACE_SETVFPREGS 28 + +/* + * PSR bits + */ +#define PSR_MODE_EL0t 0x00000000 +#define PSR_MODE_EL1t 0x00000004 +#define PSR_MODE_EL1h 0x00000005 +#define PSR_MODE_EL2t 0x00000008 +#define PSR_MODE_EL2h 0x00000009 +#define PSR_MODE_EL3t 0x0000000c +#define PSR_MODE_EL3h 0x0000000d +#define PSR_MODE_MASK 0x0000000f + +/* AArch32 CPSR bits */ +#define PSR_MODE32_BIT 0x00000010 +#define COMPAT_PSR_MODE_USR 0x00000010 +#define COMPAT_PSR_T_BIT 0x00000020 +#define COMPAT_PSR_IT_MASK 0x0600fc00 /* If-Then execution state mask */ + +/* AArch64 SPSR bits */ +#define PSR_F_BIT 0x00000040 +#define PSR_I_BIT 0x00000080 +#define PSR_A_BIT 0x00000100 +#define PSR_D_BIT 0x00000200 +#define PSR_Q_BIT 0x08000000 +#define PSR_V_BIT 0x10000000 +#define PSR_C_BIT 0x20000000 +#define PSR_Z_BIT 0x40000000 +#define PSR_N_BIT 0x80000000 + +/* + * Groups of PSR bits + */ +#define PSR_f 0xff000000 /* Flags */ +#define PSR_s 0x00ff0000 /* Status */ +#define PSR_x 0x0000ff00 /* Extension */ +#define PSR_c 0x000000ff /* Control */ + +/* + * These are 'magic' values for PTRACE_PEEKUSR that return info about where a + * process is located in memory. + */ +#define PT_TEXT_ADDR 0x10000 +#define PT_DATA_ADDR 0x10004 +#define PT_TEXT_END_ADDR 0x10008 + +#ifndef __ASSEMBLY__ + +/* + * User structures for general purpose, floating point and debug registers. + */ +struct user_pt_regs { + __u64 regs[31]; + __u64 sp; + __u64 pc; + __u64 pstate; +}; + +struct user_fpsimd_state { + __uint128_t vregs[32]; + __u32 fpsr; + __u32 fpcr; +}; + +struct user_hwdebug_state { + __u32 dbg_info; + struct { + __u64 addr; + __u32 ctrl; + } dbg_regs[16]; +}; + +#ifdef __KERNEL__ + +/* sizeof(struct user) for AArch32 */ +#define COMPAT_USER_SZ 296 +/* AArch32 uses x13 as the stack pointer... */ +#define compat_sp regs[13] +/* ... and x14 as the link register. */ +#define compat_lr regs[14] + +/* + * This struct defines the way the registers are stored on the stack during an + * exception. Note that sizeof(struct pt_regs) has to be a multiple of 16 (for + * stack alignment). struct user_pt_regs must form a prefix of struct pt_regs. + */ +struct pt_regs { + union { + struct user_pt_regs user_regs; + struct { + u64 regs[31]; + u64 sp; + u64 pc; + u64 pstate; + }; + }; + u64 orig_x0; + u64 syscallno; +}; + +#define arch_has_single_step() (1) + +#ifdef CONFIG_COMPAT +#define compat_thumb_mode(regs) \ + (((regs)->pstate & COMPAT_PSR_T_BIT)) +#else +#define compat_thumb_mode(regs) (0) +#endif + +#define user_mode(regs) \ + (((regs)->pstate & PSR_MODE_MASK) == PSR_MODE_EL0t) + +#define compat_user_mode(regs) \ + (((regs)->pstate & (PSR_MODE32_BIT | PSR_MODE_MASK)) == \ + (PSR_MODE32_BIT | PSR_MODE_EL0t)) + +#define processor_mode(regs) \ + ((regs)->pstate & PSR_MODE_MASK) + +#define interrupts_enabled(regs) \ + (!((regs)->pstate & PSR_I_BIT)) + +#define fast_interrupts_enabled(regs) \ + (!((regs)->pstate & PSR_F_BIT)) + +#define user_stack_pointer(regs) \ + ((regs)->sp) + +/* + * Are the current registers suitable for user mode? (used to maintain + * security in signal handlers) + */ +static inline int valid_user_regs(struct user_pt_regs *regs) +{ + if (user_mode(regs) && (regs->pstate & PSR_I_BIT) == 0) { + regs->pstate &= ~(PSR_F_BIT | PSR_A_BIT); + + /* The T bit is reserved for AArch64 */ + if (!(regs->pstate & PSR_MODE32_BIT)) + regs->pstate &= ~COMPAT_PSR_T_BIT; + + return 1; + } + + /* + * Force PSR to something logical... + */ + regs->pstate &= PSR_f | PSR_s | (PSR_x & ~PSR_A_BIT) | \ + COMPAT_PSR_T_BIT | PSR_MODE32_BIT; + + if (!(regs->pstate & PSR_MODE32_BIT)) { + regs->pstate &= ~COMPAT_PSR_T_BIT; + regs->pstate |= PSR_MODE_EL0t; + } + + return 0; +} + +#define instruction_pointer(regs) (regs)->pc + +#ifdef CONFIG_SMP +extern unsigned long profile_pc(struct pt_regs *regs); +#else +#define profile_pc(regs) instruction_pointer(regs) +#endif + +extern int aarch32_break_trap(struct pt_regs *regs); + +#endif /* __KERNEL__ */ + +#endif /* __ASSEMBLY__ */ + +#endif diff --git a/arch/arm64/include/asm/stacktrace.h b/arch/arm64/include/asm/stacktrace.h new file mode 100644 index 00000000000..7318f6d54aa --- /dev/null +++ b/arch/arm64/include/asm/stacktrace.h @@ -0,0 +1,29 @@ +/* + * Copyright (C) 2012 ARM Ltd. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see . + */ +#ifndef __ASM_STACKTRACE_H +#define __ASM_STACKTRACE_H + +struct stackframe { + unsigned long fp; + unsigned long sp; + unsigned long pc; +}; + +extern int unwind_frame(struct stackframe *frame); +extern void walk_stackframe(struct stackframe *frame, + int (*fn)(struct stackframe *, void *), void *data); + +#endif /* __ASM_STACKTRACE_H */ diff --git a/arch/arm64/include/asm/traps.h b/arch/arm64/include/asm/traps.h new file mode 100644 index 00000000000..10ca8ff93cc --- /dev/null +++ b/arch/arm64/include/asm/traps.h @@ -0,0 +1,30 @@ +/* + * Based on arch/arm/include/asm/traps.h + * + * Copyright (C) 2012 ARM Ltd. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see . + */ +#ifndef __ASM_TRAP_H +#define __ASM_TRAP_H + +static inline int in_exception_text(unsigned long ptr) +{ + extern char __exception_text_start[]; + extern char __exception_text_end[]; + + return ptr >= (unsigned long)&__exception_text_start && + ptr < (unsigned long)&__exception_text_end; +} + +#endif -- cgit v1.2.3