diff options
Diffstat (limited to 'arch/tile/mm')
| -rw-r--r-- | arch/tile/mm/fault.c | 41 |
1 files changed, 41 insertions, 0 deletions
diff --git a/arch/tile/mm/fault.c b/arch/tile/mm/fault.c index 6152819e555b..7863298dad4d 100644 --- a/arch/tile/mm/fault.c +++ b/arch/tile/mm/fault.c @@ -722,8 +722,49 @@ void do_page_fault(struct pt_regs *regs, int fault_num, { int is_page_fault; +#ifdef __tilegx__ + /* + * We don't need early do_page_fault_ics() support, since unlike + * Pro we don't need to worry about unlocking the atomic locks. + * There is only one current case in GX where we touch any memory + * under ICS other than our own kernel stack, and we handle that + * here. (If we crash due to trying to touch our own stack, + * we're in too much trouble for C code to help out anyway.) + */ + if (write & ~1) { + unsigned long pc = write & ~1; + if (pc >= (unsigned long) __start_unalign_asm_code && + pc < (unsigned long) __end_unalign_asm_code) { + struct thread_info *ti = current_thread_info(); + /* + * Our EX_CONTEXT is still what it was from the + * initial unalign exception, but now we've faulted + * on the JIT page. We would like to complete the + * page fault however is appropriate, and then retry + * the instruction that caused the unalign exception. + * Our state has been "corrupted" by setting the low + * bit in "sp", and stashing r0..r3 in the + * thread_info area, so we revert all of that, then + * continue as if this were a normal page fault. + */ + regs->sp &= ~1UL; + regs->regs[0] = ti->unalign_jit_tmp[0]; + regs->regs[1] = ti->unalign_jit_tmp[1]; + regs->regs[2] = ti->unalign_jit_tmp[2]; + regs->regs[3] = ti->unalign_jit_tmp[3]; + write &= 1; + } else { + pr_alert("%s/%d: ICS set at page fault at %#lx: %#lx\n", + current->comm, current->pid, pc, address); + show_regs(regs); + do_group_exit(SIGKILL); + return; + } + } +#else /* This case should have been handled by do_page_fault_ics(). */ BUG_ON(write & ~1); +#endif #if CHIP_HAS_TILE_DMA() /* |