Le 03/02/2021 à 12:59, Daniel Axtens a écrit :
Implement a limited form of KASAN for Book3S 64-bit machines running under the Radix MMU, supporting only outline mode.
diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c index a66f435dabbf..9a6fd603f0e7 100644 --- a/arch/powerpc/kernel/process.c +++ b/arch/powerpc/kernel/process.c @@ -2157,8 +2157,8 @@ void show_stack(struct task_struct *tsk, unsigned long *stack, break;stack = (unsigned long *) sp;- newsp = stack[0]; - ip = stack[STACK_FRAME_LR_SAVE]; + newsp = READ_ONCE_NOCHECK(stack[0]); + ip = READ_ONCE_NOCHECK(stack[STACK_FRAME_LR_SAVE]); if (!firstframe || ip != lr) { printk("%s["REG"] ["REG"] %pS", loglvl, sp, ip, (void *)ip); @@ -2176,17 +2176,19 @@ void show_stack(struct task_struct *tsk, unsigned long *stack, * See if this is an exception frame. * We look for the "regshere" marker in the current frame. */ - if (validate_sp(sp, tsk, STACK_INT_FRAME_SIZE) - && stack[STACK_FRAME_MARKER] == STACK_FRAME_REGS_MARKER) { + if (validate_sp(sp, tsk, STACK_INT_FRAME_SIZE) && + (READ_ONCE_NOCHECK(stack[STACK_FRAME_MARKER]) == + STACK_FRAME_REGS_MARKER)) { struct pt_regs *regs = (struct pt_regs *) (sp + STACK_FRAME_OVERHEAD);- lr = regs->link;+ lr = READ_ONCE_NOCHECK(regs->link); printk("%s--- interrupt: %lx at %pS\n", - loglvl, regs->trap, (void *)regs->nip); + loglvl, READ_ONCE_NOCHECK(regs->trap), + (void *)READ_ONCE_NOCHECK(regs->nip)); __show_regs(regs); printk("%s--- interrupt: %lx\n", - loglvl, regs->trap); + loglvl, READ_ONCE_NOCHECK(regs->trap));firstframe = 1;}
The above changes look like a bug fix not directly related to KASAN. Should be split out in another patch I think.
Christophe
