From 488896b1ab0ca8bc4cc6aa608b6ee1744ae480e7 Mon Sep 17 00:00:00 2001 From: Tao Liu Date: Mon, 19 Sep 2022 17:49:21 +0800 Subject: [PATCH 23/28] Fix "kmem" failing to print task context when address is vmalloced stack When kernel enabled CONFIG_VMAP_STACK, stack can be allocated to vmalloced area. Currently crash didn't handle the case, as a result, "kmem" will not print the task context as expected. This patch fix the bug by checking if the address is a vmalloced stack first. Before: crash> kmem ffffb7efce9bbe28 VMAP_AREA VM_STRUCT ADDRESS RANGE SIZE ffff94eb9102c640 ffff94eb9102b140 ffffb7efce9b8000 - ffffb7efce9bd000 20480 PAGE PHYSICAL MAPPING INDEX CNT FLAGS ffffdd28220dc000 1883700000 0 0 1 50000000000000 After: crash> kmem ffffb7efce9bbe28 PID: 847 COMMAND: "khungtaskd" TASK: ffff94f8038f4000 [THREAD_INFO: ffff94f8038f4000] CPU: 72 STATE: TASK_RUNNING (PANIC) VMAP_AREA VM_STRUCT ADDRESS RANGE SIZE ffff94eb9102c640 ffff94eb9102b140 ffffb7efce9b8000 - ffffb7efce9bd000 20480 PAGE PHYSICAL MAPPING INDEX CNT FLAGS ffffdd28220dc000 1883700000 0 0 1 50000000000000 Signed-off-by: Tao Liu Signed-off-by: Lianbo Jiang --- memory.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/memory.c b/memory.c index a31a430e2823..e44b59d2e805 100644 --- a/memory.c +++ b/memory.c @@ -13477,6 +13477,10 @@ kmem_search(struct meminfo *mi) * Check for a valid mapped address. */ if ((mi->memtype == KVADDR) && IS_VMALLOC_ADDR(mi->spec_addr)) { + if ((task = stkptr_to_task(vaddr)) && (tc = task_to_context(task))) { + show_context(tc); + fprintf(fp, "\n"); + } if (kvtop(NULL, mi->spec_addr, &paddr, 0)) { mi->flags = orig_flags | VMLIST_VERIFY; dump_vmlist(mi); -- 2.37.1