Re: [Crash-utility] [PATCH] ARM: fix vtop -C for kernel addresses

On ARM, [vtop -C task] doesn't work correctly for kernel addresses: it always uses swapper_pg_dir when it should be using the task's mm->pgd. The patch below fixes this, and also makes ARM handle kernel threads like the other arches. Rabin

diff --git a/arm.c b/arm.c index 4be224e..cac9a9a 100644 --- a/arm.c +++ b/arm.c @@ -1020,22 +1020,37 @@ static int arm_uvtop(struct task_context *tc, ulong uvaddr, physaddr_t *paddr, int verbose) { ulong *pgd; - ulong mm; if (!tc) error(FATAL, "current context invalid\n"); *paddr = 0; - if (IS_KVADDR(uvaddr)) - return arm_kvtop(tc, uvaddr, paddr, verbose); + if (is_kernel_thread(tc->task) && IS_KVADDR(uvaddr)) { + ulong active_mm; - mm = task_mm(tc->task, TRUE); - if (mm) - pgd = ULONG_PTR(tt->mm_struct + OFFSET(mm_struct_pgd)); - else - readmem(tc->mm_struct + OFFSET(mm_struct_pgd), KVADDR, &pgd, - sizeof(long), "mm_struct pgd", FAULT_ON_ERROR); + readmem(tc->task + OFFSET(task_struct_active_mm), + KVADDR, &active_mm, sizeof(void *), + "task active_mm contents", FAULT_ON_ERROR); + + if (!active_mm) + error(FATAL, + "no active_mm for this kernel thread\n"); + + readmem(active_mm + OFFSET(mm_struct_pgd), + KVADDR, &pgd, sizeof(long), + "mm_struct pgd", FAULT_ON_ERROR); + } else { + ulong mm; + + mm = task_mm(tc->task, TRUE); + if (mm) + pgd = ULONG_PTR(tt->mm_struct + OFFSET(mm_struct_pgd)); + else + readmem(tc->mm_struct + OFFSET(mm_struct_pgd), + KVADDR, &pgd, sizeof(long), "mm_struct pgd", + FAULT_ON_ERROR); + } return arm_vtop(uvaddr, pgd, paddr, verbose); } -- Crash-utility mailing list Crash-utility(a)redhat.com https://www.redhat.com/mailman/listinfo/crash-utility