[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 <stevel@mwwireless.net>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
diff --git a/arch/arm/mm/alignment.c b/arch/arm/mm/alignment.c
index 81f4a8a..4b39d86 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_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 @@
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 @@
{
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 @@
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 @@
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 */