[PATCH] Fix kmem failing to print task context when address is vmalloced stack

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



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)

	  PAGE         PHYSICAL      MAPPING       INDEX CNT FLAGS
    ffffdd28220dc000 1883700000                0        0  1 50000000000000

Signed-off-by: Tao Liu <ltao@xxxxxxxxxx>
---
 memory.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/memory.c b/memory.c
index 7339f0c..7a1bf9c 100644
--- a/memory.c
+++ b/memory.c
@@ -13477,6 +13477,11 @@ 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");
+			goto mem_map;
+		}
 		if (kvtop(NULL, mi->spec_addr, &paddr, 0)) {
 			mi->flags = orig_flags | VMLIST_VERIFY;
 			dump_vmlist(mi);
-- 
2.33.1

--
Crash-utility mailing list
Crash-utility@xxxxxxxxxx
https://listman.redhat.com/mailman/listinfo/crash-utility
Contribution Guidelines: https://github.com/crash-utility/crash/wiki




[Index of Archives]     [Fedora Development]     [Fedora Desktop]     [Fedora SELinux]     [Yosemite News]     [KDE Users]     [Fedora Tools]

 

Powered by Linux