Re: [Crash-utility] [PATCH] Fix "vm -M" option to properly display virtual memory data of the task

> So how about adding a sentence saying it? > -M mm if the mm_struct address has been removed from the > task_struct > of an exiting task, the virtual memory data cannot be > displayed. > However, if the address can be determined from the kernel > stack, > it can be entered manually in order to try to resurrect > the > - virtual memory data of the task. > + virtual memory data of the task. This option is ignored > when > + the task_struct has a non-NULL mm_struct address. > > This looks much better. But it still accepts an invalid argument, for example: crash> vm -M 0xh crash> vm -M 0xdeadbeef How about the following changes? diff --git a/help.c b/help.c index 56a9d8274525..3006ac9180ae 100644 --- a/help.c +++ b/help.c @@ -4695,6 +4695,7 @@ char *help_vm[] = { " However, if the address can be determined from the kernel stack,", " it can be entered manually in order to try to resurrect the", " virtual memory data of the task.", +" NOTE: this option is only used when the task_struct's mm is NULL.", " -R reference search for references to this number or filename.", " -m dump the mm_struct associated with the task.", " -v dump all of the vm_area_structs associated with the task.", diff --git a/memory.c b/memory.c index 592a5ef49d50..0968ff930eb9 100644 --- a/memory.c +++ b/memory.c @@ -3559,6 +3559,8 @@ cmd_vm(void) case 'M': pc->curcmd_private = htoll(optarg, FAULT_ON_ERROR, NULL); pc->curcmd_flags |= MM_STRUCT_FORCE; + if (!IS_KVADDR(pc->curcmd_private)) + argerrs++; break; case 'f': With the above patch, it can properly deal with an invalid argument as below: crash> vm -M 0xh Usage: vm [-p | -P vma | -M mm | -v | -m | -x | -d | [-R reference] [pid | task]] [-f vm_flags] Enter "help vm" for details. crash> vm -M 0xdeadbeef Usage: vm [-p | -P vma | -M mm | -v | -m | -x | -d | [-R reference] [pid | task]] [-f vm_flags] Enter "help vm" for details.