diff options
Diffstat (limited to 'arch/powerpc/mm/book3s64/slb.c')
| -rw-r--r-- | arch/powerpc/mm/book3s64/slb.c | 40 |
1 files changed, 23 insertions, 17 deletions
diff --git a/arch/powerpc/mm/book3s64/slb.c b/arch/powerpc/mm/book3s64/slb.c index 584567970c11..c91bd85eb90e 100644 --- a/arch/powerpc/mm/book3s64/slb.c +++ b/arch/powerpc/mm/book3s64/slb.c @@ -10,6 +10,7 @@ */ #include <asm/asm-prototypes.h> +#include <asm/interrupt.h> #include <asm/mmu.h> #include <asm/mmu_context.h> #include <asm/paca.h> @@ -813,8 +814,9 @@ static long slb_allocate_user(struct mm_struct *mm, unsigned long ea) return slb_insert_entry(ea, context, flags, ssize, false); } -long do_slb_fault(struct pt_regs *regs, unsigned long ea) +DEFINE_INTERRUPT_HANDLER_RAW(do_slb_fault) { + unsigned long ea = regs->dar; unsigned long id = get_region_id(ea); /* IRQs are not reconciled here, so can't check irqs_disabled */ @@ -824,19 +826,21 @@ long do_slb_fault(struct pt_regs *regs, unsigned long ea) return -EINVAL; /* - * SLB kernel faults must be very careful not to touch anything - * that is not bolted. E.g., PACA and global variables are okay, - * mm->context stuff is not. - * - * SLB user faults can access all of kernel memory, but must be - * careful not to touch things like IRQ state because it is not - * "reconciled" here. The difficulty is that we must use - * fast_exception_return to return from kernel SLB faults without - * looking at possible non-bolted memory. We could test user vs - * kernel faults in the interrupt handler asm and do a full fault, - * reconcile, ret_from_except for user faults which would make them - * first class kernel code. But for performance it's probably nicer - * if they go via fast_exception_return too. + * SLB kernel faults must be very careful not to touch anything that is + * not bolted. E.g., PACA and global variables are okay, mm->context + * stuff is not. SLB user faults may access all of memory (and induce + * one recursive SLB kernel fault), so the kernel fault must not + * trample on the user fault state at those points. + */ + + /* + * This is a raw interrupt handler, for performance, so that + * fast_interrupt_return can be used. The handler must not touch local + * irq state, or schedule. We could test for usermode and upgrade to a + * normal process context (synchronous) interrupt for those, which + * would make them first-class kernel code and able to be traced and + * instrumented, although performance would suffer a bit, it would + * probably be a good tradeoff. */ if (id >= LINEAR_MAP_REGION_ID) { long err; @@ -865,13 +869,15 @@ long do_slb_fault(struct pt_regs *regs, unsigned long ea) } } -void do_bad_slb_fault(struct pt_regs *regs, unsigned long ea, long err) +DEFINE_INTERRUPT_HANDLER(do_bad_slb_fault) { + int err = regs->result; + if (err == -EFAULT) { if (user_mode(regs)) - _exception(SIGSEGV, regs, SEGV_BNDERR, ea); + _exception(SIGSEGV, regs, SEGV_BNDERR, regs->dar); else - bad_page_fault(regs, ea, SIGSEGV); + bad_page_fault(regs, SIGSEGV); } else if (err == -EINVAL) { unrecoverable_exception(regs); } else { |