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OpenCloudOS-Kernel
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[SPARC64]: Unaligned accesses to userspace are hard errors. 

Userspace is forbidden from making unaligned loads and
stores.  So if we get an unaligned trap due to a
{get,put}_user(), signal a fault and run the exception
handler.

Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
David S. Miller 2006-11-28 20:18:05 -08:00
parent 6e7726e16f
commit c449c38b5d
1 changed files with 31 additions and 13 deletions
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44
arch/sparc64/kernel/unaligned.c
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@ -243,7 +243,7 @@ static inline int ok_for_kernel(unsigned int insn)
return !floating_point_load_or_store_p(insn);
}
static void kernel_mna_trap_fault(void)
static void kernel_mna_trap_fault(int fixup_tstate_asi)
{
struct pt_regs *regs = current_thread_info()->kern_una_regs;
unsigned int insn = current_thread_info()->kern_una_insn;
@ -274,18 +274,15 @@ static void kernel_mna_trap_fault(void)
regs->tpc = entry->fixup;
regs->tnpc = regs->tpc + 4;
regs->tstate &= ~TSTATE_ASI;
regs->tstate |= (ASI_AIUS << 24UL);
if (fixup_tstate_asi) {
regs->tstate &= ~TSTATE_ASI;
regs->tstate |= (ASI_AIUS << 24UL);
}
}
asmlinkage void kernel_unaligned_trap(struct pt_regs *regs, unsigned int insn)
static void log_unaligned(struct pt_regs *regs)
{
static unsigned long count, last_time;
enum direction dir = decode_direction(insn);
int size = decode_access_size(insn);
current_thread_info()->kern_una_regs = regs;
current_thread_info()->kern_una_insn = insn;
if (jiffies - last_time > 5 * HZ)
count = 0;
@ -295,6 +292,28 @@ asmlinkage void kernel_unaligned_trap(struct pt_regs *regs, unsigned int insn)
printk("Kernel unaligned access at TPC[%lx] ", regs->tpc);
print_symbol("%s\n", regs->tpc);
}
}
asmlinkage void kernel_unaligned_trap(struct pt_regs *regs, unsigned int insn)
{
enum direction dir = decode_direction(insn);
int size = decode_access_size(insn);
int orig_asi, asi;
current_thread_info()->kern_una_regs = regs;
current_thread_info()->kern_una_insn = insn;
orig_asi = asi = decode_asi(insn, regs);
/* If this is a {get,put}_user() on an unaligned userspace pointer,
* just signal a fault and do not log the event.
*/
if (asi == ASI_AIUS) {
kernel_mna_trap_fault(0);
return;
}
log_unaligned(regs);
if (!ok_for_kernel(insn) || dir == both) {
printk("Unsupported unaligned load/store trap for kernel "
@ -302,10 +321,10 @@ asmlinkage void kernel_unaligned_trap(struct pt_regs *regs, unsigned int insn)
unaligned_panic("Kernel does fpu/atomic "
"unaligned load/store.", regs);
kernel_mna_trap_fault();
kernel_mna_trap_fault(0);
} else {
unsigned long addr, *reg_addr;
int orig_asi, asi, err;
int err;
addr = compute_effective_address(regs, insn,
((insn >> 25) & 0x1f));
@ -315,7 +334,6 @@ asmlinkage void kernel_unaligned_trap(struct pt_regs *regs, unsigned int insn)
regs->tpc, dirstrings[dir], addr, size,
regs->u_regs[UREG_RETPC]);
#endif
orig_asi = asi = decode_asi(insn, regs);
switch (asi) {
case ASI_NL:
case ASI_AIUPL:
@ -365,7 +383,7 @@ asmlinkage void kernel_unaligned_trap(struct pt_regs *regs, unsigned int insn)
/* Not reached... */
}
if (unlikely(err))
kernel_mna_trap_fault();
kernel_mna_trap_fault(1);
else
advance(regs);
}