From f21ee2d4245293ee6906eb7afd0a701f40e839b9 Mon Sep 17 00:00:00 2001 From: Steve Longerbeam Date: Wed, 31 Aug 2005 21:22:20 +0100 Subject: [ARM] 2867/2: unaligned ldrd/strd fixups Patch from Steve Longerbeam Adds an implementation of unaligned LDRD and STRD fixups. Also fixes a bug where do_alignment() would misinterpret and fixup an unaligned LDRD/STRD as LDRH/STRH, causing memory corruption. This is the same as Patch #2867/1, but with minor whitespace and comments changes, plus a check for arch-level >= v5TE before printing ai_dword count in proc_alignment_read(). Signed-off-by: Steve Longerbeam Signed-off-by: Russell King --- arch/arm/mm/alignment.c | 70 +++++++++++++++++++++++++++++++++++++++---------- 1 file changed, 56 insertions(+), 14 deletions(-) (limited to 'arch/arm/mm/alignment.c') diff --git a/arch/arm/mm/alignment.c b/arch/arm/mm/alignment.c index 81f4a8a2d34..4b39d867ac1 100644 --- a/arch/arm/mm/alignment.c +++ b/arch/arm/mm/alignment.c @@ -45,7 +45,7 @@ #define LDST_P_EQ_U(i) ((((i) ^ ((i) >> 1)) & (1 << 23)) == 0) -#define LDSTH_I_BIT(i) (i & (1 << 22)) /* half-word immed */ +#define LDSTHD_I_BIT(i) (i & (1 << 22)) /* double/half-word immed */ #define LDM_S_BIT(i) (i & (1 << 22)) /* write CPSR from SPSR */ #define RN_BITS(i) ((i >> 16) & 15) /* Rn */ @@ -68,6 +68,7 @@ static unsigned long ai_sys; 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; @@ -93,6 +94,8 @@ proc_alignment_read(char *page, char **start, off_t off, int count, int *eof, p += sprintf(p, "Skipped:\t%lu\n", ai_skipped); p += sprintf(p, "Half:\t\t%lu\n", ai_half); p += sprintf(p, "Word:\t\t%lu\n", ai_word); + if (cpu_architecture() >= CPU_ARCH_ARMv5TE) + p += sprintf(p, "DWord:\t\t%lu\n", ai_dword); p += sprintf(p, "Multi:\t\t%lu\n", ai_multi); p += sprintf(p, "User faults:\t%i (%s)\n", ai_usermode, usermode_action[ai_usermode]); @@ -283,12 +286,6 @@ do_alignment_ldrhstrh(unsigned long addr, unsigned long instr, struct pt_regs *r { unsigned int rd = RD_BITS(instr); - if ((instr & 0x01f00ff0) == 0x01000090) - goto swp; - - if ((instr & 0x90) != 0x90 || (instr & 0x60) == 0) - goto bad; - ai_half += 1; if (user_mode(regs)) @@ -323,10 +320,47 @@ do_alignment_ldrhstrh(unsigned long addr, unsigned long instr, struct pt_regs *r return TYPE_LDST; - swp: - printk(KERN_ERR "Alignment trap: not handling swp instruction\n"); - bad: - return TYPE_ERROR; + fault: + return TYPE_FAULT; +} + +static int +do_alignment_ldrdstrd(unsigned long addr, unsigned long instr, + struct pt_regs *regs) +{ + unsigned int rd = RD_BITS(instr); + + ai_dword += 1; + + if (user_mode(regs)) + goto user; + + if ((instr & 0xf0) == 0xd0) { + unsigned long val; + get32_unaligned_check(val, addr); + regs->uregs[rd] = val; + get32_unaligned_check(val, addr+4); + regs->uregs[rd+1] = val; + } else { + put32_unaligned_check(regs->uregs[rd], addr); + put32_unaligned_check(regs->uregs[rd+1], addr+4); + } + + return TYPE_LDST; + + user: + if ((instr & 0xf0) == 0xd0) { + unsigned long val; + get32t_unaligned_check(val, addr); + regs->uregs[rd] = val; + get32t_unaligned_check(val, addr+4); + regs->uregs[rd+1] = val; + } else { + put32t_unaligned_check(regs->uregs[rd], addr); + put32t_unaligned_check(regs->uregs[rd+1], addr+4); + } + + return TYPE_LDST; fault: return TYPE_FAULT; @@ -617,12 +651,20 @@ do_alignment(unsigned long addr, unsigned int fsr, struct pt_regs *regs) regs->ARM_pc += thumb_mode(regs) ? 2 : 4; switch (CODING_BITS(instr)) { - case 0x00000000: /* ldrh or strh */ - if (LDSTH_I_BIT(instr)) + case 0x00000000: /* 3.13.4 load/store instruction extensions */ + if (LDSTHD_I_BIT(instr)) offset.un = (instr & 0xf00) >> 4 | (instr & 15); else offset.un = regs->uregs[RM_BITS(instr)]; - handler = do_alignment_ldrhstrh; + + if ((instr & 0x000000f0) == 0x000000b0 || /* LDRH, STRH */ + (instr & 0x001000f0) == 0x001000f0) /* LDRSH */ + handler = do_alignment_ldrhstrh; + else if ((instr & 0x001000f0) == 0x000000d0 || /* LDRD */ + (instr & 0x001000f0) == 0x000000f0) /* STRD */ + handler = do_alignment_ldrdstrd; + else + goto bad; break; case 0x04000000: /* ldr or str immediate */ -- cgit v1.2.3