diff options
Diffstat (limited to 'arch/arm/mm/alignment.c')
| -rw-r--r-- | arch/arm/mm/alignment.c | 189 |
1 files changed, 125 insertions, 64 deletions
diff --git a/arch/arm/mm/alignment.c b/arch/arm/mm/alignment.c index 6f4585b89078..3c6ddb1afdc4 100644 --- a/arch/arm/mm/alignment.c +++ b/arch/arm/mm/alignment.c @@ -1,3 +1,4 @@ +// SPDX-License-Identifier: GPL-2.0-only /* * linux/arch/arm/mm/alignment.c * @@ -6,27 +7,26 @@ * Thumb alignment fault fixups (c) 2004 MontaVista Software, Inc. * - Adapted from gdb/sim/arm/thumbemu.c -- Thumb instruction emulation. * Copyright (C) 1996, Cygnus Software Technologies 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. */ #include <linux/moduleparam.h> #include <linux/compiler.h> #include <linux/kernel.h> +#include <linux/sched/debug.h> #include <linux/errno.h> #include <linux/string.h> #include <linux/proc_fs.h> #include <linux/seq_file.h> #include <linux/init.h> -#include <linux/sched.h> +#include <linux/sched/signal.h> #include <linux/uaccess.h> #include <asm/cp15.h> #include <asm/system_info.h> -#include <asm/unaligned.h> +#include <linux/unaligned.h> +#include <asm/opcodes.h> #include "fault.h" +#include "mm.h" /* * 32-bit misaligned trap handler (c) 1998 San Mehat (CCC) -July 1998 @@ -39,6 +39,7 @@ * This code is not portable to processors with late data abort handling. */ #define CODING_BITS(i) (i & 0x0e000000) +#define COND_BITS(i) (i & 0xf0000000) #define LDST_I_BIT(i) (i & (1 << 26)) /* Immediate constant */ #define LDST_P_BIT(i) (i & (1 << 24)) /* Preindex */ @@ -74,12 +75,14 @@ static unsigned long ai_user; static unsigned long ai_sys; +static void *ai_sys_last_pc; static unsigned long ai_skipped; static unsigned long ai_half; static unsigned long ai_word; static unsigned long ai_dword; static unsigned long ai_multi; static int ai_usermode; +static unsigned long cr_no_alignment; core_param(alignment, ai_usermode, int, 0600); @@ -90,7 +93,7 @@ core_param(alignment, ai_usermode, int, 0600); /* Return true if and only if the ARMv6 unaligned access model is in use. */ static bool cpu_is_v6_unaligned(void) { - return cpu_architecture() >= CPU_ARCH_ARMv6 && (cr_alignment & CR_U); + return cpu_architecture() >= CPU_ARCH_ARMv6 && get_cr() & CR_U; } static int safe_usermode(int new_usermode, bool warn) @@ -108,7 +111,7 @@ static int safe_usermode(int new_usermode, bool warn) new_usermode |= UM_FIXUP; if (warn) - printk(KERN_WARNING "alignment: ignoring faults is unsafe on this CPU. Defaulting to fixup mode.\n"); + pr_warn("alignment: ignoring faults is unsafe on this CPU. Defaulting to fixup mode.\n"); } return new_usermode; @@ -127,7 +130,7 @@ static const char *usermode_action[] = { static int alignment_proc_show(struct seq_file *m, void *v) { seq_printf(m, "User:\t\t%lu\n", ai_user); - seq_printf(m, "System:\t\t%lu\n", ai_sys); + seq_printf(m, "System:\t\t%lu (%pS)\n", ai_sys, ai_sys_last_pc); seq_printf(m, "Skipped:\t%lu\n", ai_skipped); seq_printf(m, "Half:\t\t%lu\n", ai_half); seq_printf(m, "Word:\t\t%lu\n", ai_word); @@ -159,12 +162,12 @@ static ssize_t alignment_proc_write(struct file *file, const char __user *buffer return count; } -static const struct file_operations alignment_proc_fops = { - .open = alignment_proc_open, - .read = seq_read, - .llseek = seq_lseek, - .release = single_release, - .write = alignment_proc_write, +static const struct proc_ops alignment_proc_ops = { + .proc_open = alignment_proc_open, + .proc_read = seq_read, + .proc_lseek = seq_lseek, + .proc_release = single_release, + .proc_write = alignment_proc_write, }; #endif /* CONFIG_PROC_FS */ @@ -196,7 +199,7 @@ union offset_union { THUMB( "1: "ins" %1, [%2]\n" ) \ THUMB( " add %2, %2, #1\n" ) \ "2:\n" \ - " .pushsection .fixup,\"ax\"\n" \ + " .pushsection .text.fixup,\"ax\"\n" \ " .align 2\n" \ "3: mov %0, #1\n" \ " b 2b\n" \ @@ -256,7 +259,7 @@ union offset_union { " mov %1, %1, "NEXT_BYTE"\n" \ "2: "ins" %1, [%2]\n" \ "3:\n" \ - " .pushsection .fixup,\"ax\"\n" \ + " .pushsection .text.fixup,\"ax\"\n" \ " .align 2\n" \ "4: mov %0, #1\n" \ " b 3b\n" \ @@ -296,7 +299,7 @@ union offset_union { " mov %1, %1, "NEXT_BYTE"\n" \ "4: "ins" %1, [%2]\n" \ "5:\n" \ - " .pushsection .fixup,\"ax\"\n" \ + " .pushsection .text.fixup,\"ax\"\n" \ " .align 2\n" \ "6: mov %0, #1\n" \ " b 5b\n" \ @@ -321,7 +324,7 @@ union offset_union { __put32_unaligned_check("strbt", val, addr) static void -do_alignment_finish_ldst(unsigned long addr, unsigned long instr, struct pt_regs *regs, union offset_union offset) +do_alignment_finish_ldst(unsigned long addr, u32 instr, struct pt_regs *regs, union offset_union offset) { if (!LDST_U_BIT(instr)) offset.un = -offset.un; @@ -334,7 +337,7 @@ do_alignment_finish_ldst(unsigned long addr, unsigned long instr, struct pt_regs } static int -do_alignment_ldrhstrh(unsigned long addr, unsigned long instr, struct pt_regs *regs) +do_alignment_ldrhstrh(unsigned long addr, u32 instr, struct pt_regs *regs) { unsigned int rd = RD_BITS(instr); @@ -360,15 +363,21 @@ do_alignment_ldrhstrh(unsigned long addr, unsigned long instr, struct pt_regs *r user: if (LDST_L_BIT(instr)) { unsigned long val; + unsigned int __ua_flags = uaccess_save_and_enable(); + get16t_unaligned_check(val, addr); + uaccess_restore(__ua_flags); /* signed half-word? */ if (instr & 0x40) val = (signed long)((signed short) val); regs->uregs[rd] = val; - } else + } else { + unsigned int __ua_flags = uaccess_save_and_enable(); put16t_unaligned_check(regs->uregs[rd], addr); + uaccess_restore(__ua_flags); + } return TYPE_LDST; @@ -377,8 +386,7 @@ do_alignment_ldrhstrh(unsigned long addr, unsigned long instr, struct pt_regs *r } static int -do_alignment_ldrdstrd(unsigned long addr, unsigned long instr, - struct pt_regs *regs) +do_alignment_ldrdstrd(unsigned long addr, u32 instr, struct pt_regs *regs) { unsigned int rd = RD_BITS(instr); unsigned int rd2; @@ -415,14 +423,21 @@ do_alignment_ldrdstrd(unsigned long addr, unsigned long instr, user: if (load) { - unsigned long val; + unsigned long val, val2; + unsigned int __ua_flags = uaccess_save_and_enable(); + get32t_unaligned_check(val, addr); + get32t_unaligned_check(val2, addr + 4); + + uaccess_restore(__ua_flags); + regs->uregs[rd] = val; - get32t_unaligned_check(val, addr + 4); - regs->uregs[rd2] = val; + regs->uregs[rd2] = val2; } else { + unsigned int __ua_flags = uaccess_save_and_enable(); put32t_unaligned_check(regs->uregs[rd], addr); put32t_unaligned_check(regs->uregs[rd2], addr + 4); + uaccess_restore(__ua_flags); } return TYPE_LDST; @@ -433,7 +448,7 @@ do_alignment_ldrdstrd(unsigned long addr, unsigned long instr, } static int -do_alignment_ldrstr(unsigned long addr, unsigned long instr, struct pt_regs *regs) +do_alignment_ldrstr(unsigned long addr, u32 instr, struct pt_regs *regs) { unsigned int rd = RD_BITS(instr); @@ -453,10 +468,15 @@ do_alignment_ldrstr(unsigned long addr, unsigned long instr, struct pt_regs *reg trans: if (LDST_L_BIT(instr)) { unsigned int val; + unsigned int __ua_flags = uaccess_save_and_enable(); get32t_unaligned_check(val, addr); + uaccess_restore(__ua_flags); regs->uregs[rd] = val; - } else + } else { + unsigned int __ua_flags = uaccess_save_and_enable(); put32t_unaligned_check(regs->uregs[rd], addr); + uaccess_restore(__ua_flags); + } return TYPE_LDST; fault: @@ -477,7 +497,7 @@ do_alignment_ldrstr(unsigned long addr, unsigned long instr, struct pt_regs *reg * PU = 10 A B */ static int -do_alignment_ldmstm(unsigned long addr, unsigned long instr, struct pt_regs *regs) +do_alignment_ldmstm(unsigned long addr, u32 instr, struct pt_regs *regs) { unsigned int rd, rn, correction, nr_regs, regbits; unsigned long eaddr, newaddr; @@ -518,7 +538,7 @@ do_alignment_ldmstm(unsigned long addr, unsigned long instr, struct pt_regs *reg * processor for us. */ if (addr != eaddr) { - printk(KERN_ERR "LDMSTM: PC = %08lx, instr = %08lx, " + pr_err("LDMSTM: PC = %08lx, instr = %08x, " "addr = %08lx, eaddr = %08lx\n", instruction_pointer(regs), instr, addr, eaddr); show_regs(regs); @@ -526,6 +546,7 @@ do_alignment_ldmstm(unsigned long addr, unsigned long instr, struct pt_regs *reg #endif if (user_mode(regs)) { + unsigned int __ua_flags = uaccess_save_and_enable(); for (regbits = REGMASK_BITS(instr), rd = 0; regbits; regbits >>= 1, rd += 1) if (regbits & 1) { @@ -537,6 +558,7 @@ do_alignment_ldmstm(unsigned long addr, unsigned long instr, struct pt_regs *reg put32t_unaligned_check(regs->uregs[rd], eaddr); eaddr += 4; } + uaccess_restore(__ua_flags); } else { for (regbits = REGMASK_BITS(instr), rd = 0; regbits; regbits >>= 1, rd += 1) @@ -562,7 +584,7 @@ fault: return TYPE_FAULT; bad: - printk(KERN_ERR "Alignment trap: not handling ldm with s-bit set\n"); + pr_err("Alignment trap: not handling ldm with s-bit set\n"); return TYPE_ERROR; } @@ -672,7 +694,7 @@ thumb2arm(u16 tinstr) return subset[(L<<1) | ((tinstr & (1<<8)) >> 8)] | (tinstr & 255); /* register_list */ } - /* Else fall through for illegal instruction case */ + fallthrough; /* for illegal instruction case */ default: return BAD_INSTR; @@ -693,10 +715,10 @@ thumb2arm(u16 tinstr) * 2. Register name Rt from ARMv7 is same as Rd from ARMv6 (Rd is Rt) */ static void * -do_alignment_t32_to_handler(unsigned long *pinstr, struct pt_regs *regs, +do_alignment_t32_to_handler(u32 *pinstr, struct pt_regs *regs, union offset_union *poffset) { - unsigned long instr = *pinstr; + u32 instr = *pinstr; u16 tinst1 = (instr >> 16) & 0xffff; u16 tinst2 = instr & 0xffff; @@ -728,6 +750,8 @@ do_alignment_t32_to_handler(unsigned long *pinstr, struct pt_regs *regs, case 0xe8e0: case 0xe9e0: poffset->un = (tinst2 & 0xff) << 2; + fallthrough; + case 0xe940: case 0xe9c0: return do_alignment_ldrdstrd; @@ -742,17 +766,48 @@ do_alignment_t32_to_handler(unsigned long *pinstr, struct pt_regs *regs, return NULL; } +static int alignment_get_arm(struct pt_regs *regs, u32 *ip, u32 *inst) +{ + u32 instr = 0; + int fault; + + if (user_mode(regs)) + fault = get_user(instr, ip); + else + fault = get_kernel_nofault(instr, ip); + + *inst = __mem_to_opcode_arm(instr); + + return fault; +} + +static int alignment_get_thumb(struct pt_regs *regs, u16 *ip, u16 *inst) +{ + u16 instr = 0; + int fault; + + if (user_mode(regs)) + fault = get_user(instr, ip); + else + fault = get_kernel_nofault(instr, ip); + + *inst = __mem_to_opcode_thumb16(instr); + + return fault; +} + static int do_alignment(unsigned long addr, unsigned int fsr, struct pt_regs *regs) { - union offset_union uninitialized_var(offset); - unsigned long instr = 0, instrptr; - int (*handler)(unsigned long addr, unsigned long instr, struct pt_regs *regs); + union offset_union offset; + unsigned long instrptr; + int (*handler)(unsigned long addr, u32 instr, struct pt_regs *regs); unsigned int type; - unsigned int fault; + u32 instr = 0; u16 tinstr = 0; int isize = 4; int thumb2_32b = 0; + int fault; if (interrupts_enabled(regs)) local_irq_enable(); @@ -761,22 +816,24 @@ do_alignment(unsigned long addr, unsigned int fsr, struct pt_regs *regs) if (thumb_mode(regs)) { u16 *ptr = (u16 *)(instrptr & ~1); - fault = probe_kernel_address(ptr, tinstr); + + fault = alignment_get_thumb(regs, ptr, &tinstr); if (!fault) { if (cpu_architecture() >= CPU_ARCH_ARMv7 && IS_T32(tinstr)) { /* Thumb-2 32-bit */ - u16 tinst2 = 0; - fault = probe_kernel_address(ptr + 1, tinst2); - instr = (tinstr << 16) | tinst2; + u16 tinst2; + fault = alignment_get_thumb(regs, ptr + 1, &tinst2); + instr = __opcode_thumb32_compose(tinstr, tinst2); thumb2_32b = 1; } else { isize = 2; instr = thumb2arm(tinstr); } } - } else - fault = probe_kernel_address(instrptr, instr); + } else { + fault = alignment_get_arm(regs, (void *)instrptr, &instr); + } if (fault) { type = TYPE_FAULT; @@ -787,6 +844,7 @@ do_alignment(unsigned long addr, unsigned int fsr, struct pt_regs *regs) goto user; ai_sys += 1; + ai_sys_last_pc = (void *)instruction_pointer(regs); fixup: @@ -812,6 +870,8 @@ do_alignment(unsigned long addr, unsigned int fsr, struct pt_regs *regs) break; case 0x04000000: /* ldr or str immediate */ + if (COND_BITS(instr) == 0xf0000000) /* NEON VLDn, VSTn */ + goto bad; offset.un = OFFSET_BITS(instr); handler = do_alignment_ldrstr; break; @@ -875,6 +935,9 @@ do_alignment(unsigned long addr, unsigned int fsr, struct pt_regs *regs) if (type == TYPE_LDST) do_alignment_finish_ldst(addr, instr, regs, offset); + if (thumb_mode(regs)) + regs->ARM_cpsr = it_advance(regs->ARM_cpsr); + return 0; bad_or_fault: @@ -887,14 +950,14 @@ do_alignment(unsigned long addr, unsigned int fsr, struct pt_regs *regs) return 0; swp: - printk(KERN_ERR "Alignment trap: not handling swp instruction\n"); + pr_err("Alignment trap: not handling swp instruction\n"); bad: /* * Oops, we didn't handle the instruction. */ - printk(KERN_ERR "Alignment trap: not handling instruction " - "%0*lx at [<%08lx>]\n", + pr_err("Alignment trap: not handling instruction " + "%0*x at [<%08lx>]\n", isize << 1, isize == 2 ? tinstr : instr, instrptr); ai_skipped += 1; @@ -904,7 +967,7 @@ do_alignment(unsigned long addr, unsigned int fsr, struct pt_regs *regs) ai_user += 1; if (ai_usermode & UM_WARN) - printk("Alignment trap: %s (%d) PC=0x%08lx Instr=0x%0*lx " + printk("Alignment trap: %s (%d) PC=0x%08lx Instr=0x%0*x " "Address=0x%08lx FSR 0x%03x\n", current->comm, task_pid_nr(current), instrptr, isize << 1, @@ -915,14 +978,7 @@ do_alignment(unsigned long addr, unsigned int fsr, struct pt_regs *regs) goto fixup; if (ai_usermode & UM_SIGNAL) { - siginfo_t si; - - si.si_signo = SIGBUS; - si.si_errno = 0; - si.si_code = BUS_ADRALN; - si.si_addr = (void __user *)addr; - - force_sig_info(si.si_signo, &si, current); + force_sig_fault(SIGBUS, BUS_ADRALN, (void __user *)addr); } else { /* * We're about to disable the alignment trap and return to @@ -937,15 +993,22 @@ do_alignment(unsigned long addr, unsigned int fsr, struct pt_regs *regs) * there is no work pending for this thread. */ raw_local_irq_disable(); - if (!(current_thread_info()->flags & _TIF_WORK_MASK)) + if (!(read_thread_flags() & _TIF_WORK_MASK)) set_cr(cr_no_alignment); } return 0; } +static int __init noalign_setup(char *__unused) +{ + set_cr(__clear_cr(CR_A)); + return 1; +} +__setup("noalign", noalign_setup); + /* - * This needs to be done after sysctl_init, otherwise sys/ will be + * This needs to be done after sysctl_init_bases(), otherwise sys/ will be * overwritten. Actually, this shouldn't be in sys/ at all since * it isn't a sysctl, and it doesn't contain sysctl information. * We now locate it in /proc/cpu/alignment instead. @@ -956,19 +1019,17 @@ static int __init alignment_init(void) struct proc_dir_entry *res; res = proc_create("cpu/alignment", S_IWUSR | S_IRUGO, NULL, - &alignment_proc_fops); + &alignment_proc_ops); if (!res) return -ENOMEM; #endif -#ifdef CONFIG_CPU_CP15 if (cpu_is_v6_unaligned()) { - cr_alignment &= ~CR_A; - cr_no_alignment &= ~CR_A; - set_cr(cr_alignment); + set_cr(__clear_cr(CR_A)); ai_usermode = safe_usermode(ai_usermode, false); } -#endif + + cr_no_alignment = get_cr() & ~CR_A; hook_fault_code(FAULT_CODE_ALIGNMENT, do_alignment, SIGBUS, BUS_ADRALN, "alignment exception"); |