[Crash-utility] Re: [PATCH 2/2] Fix for failing to load kernel module

Hi Lianbo, I have the patch tested, looks good to me, so ack.

Thanks, Tao Liu On Wed, Jun 5, 2024 at 6:06 PM Lianbo Jiang <lijiang(a)redhat.com&gt; wrote: > > In some kernel modules such as libie.ko, the mem[MOD_TEXT].size > may be zero, currently crash will only check its value to determine > if the module is valid, otherwise it fails to load kernel module with > the following warning and error: > > WARNING: invalid kernel module size: 0 > KERNEL: /lib/modules/6.10.0-rc1+/build/vmlinux > DUMPFILE: /proc/kcore > CPUS: 64 > DATE: Wed Jun 5 12:49:02 IDT 2024 > UPTIME: 5 days, 05:57:21 > LOAD AVERAGE: 0.28, 0.06, 0.02 > TASKS: 806 > NODENAME: xxxx > RELEASE: 6.10.0-rc1+ > VERSION: #1 SMP PREEMPT_DYNAMIC Fri May 31 04:56:59 IDT 2024 > MACHINE: x86_64 (2100 Mhz) > MEMORY: 1.6 GB > PID: 203686 > COMMAND: "crash" > TASK: ffff9f9bf66d0000 [THREAD_INFO: ffff9f9bf66d0000] > CPU: 52 > STATE: TASK_RUNNING (ACTIVE) > > crash> mod > mod: cannot access vmalloc'd module memory > crash> > > Lets count the module size to check if the module is valid, that will > avoid the current failure. > > Signed-off-by: Lianbo Jiang <lijiang(a)redhat.com&gt; > --- > kernel.c | 20 ++++++++++++++++---- > 1 file changed, 16 insertions(+), 4 deletions(-) > > diff --git a/kernel.c b/kernel.c > index 1728b70c1b5c..e0dc23b9b233 100644 > --- a/kernel.c > +++ b/kernel.c > @@ -3821,9 +3821,21 @@ module_init(void) > case KALLSYMS_V2: > if (THIS_KERNEL_VERSION >= LINUX(2,6,27)) { > numksyms = UINT(modbuf + OFFSET(module_num_symtab)); > - if (MODULE_MEMORY()) > - /* check mem[MOD_TEXT].size only */ > - size = UINT(modbuf + OFFSET(module_mem) + OFFSET(module_memory_size)); > + if (MODULE_MEMORY()) { > + /* > + * The mem[MOD_TEXT].size may be zero, lets count > + * the module size as below. > + */ > + int t; > + size = 0; > + for_each_mod_mem_type(t) { > + if (t == MOD_INIT_TEXT) > + break; > + size += UINT(modbuf + OFFSET(module_mem) + > + SIZE(module_memory) * t + > + OFFSET(module_memory_size)); > + } > + } > else > size = UINT(modbuf + MODULE_OFFSET2(module_core_size, rx)); > } else { > @@ -3926,7 +3938,7 @@ verify_modules(void) > > for (i = 0, found = FALSE; i < kt->mods_installed; i++) { > lm = &st->load_modules[i]; > - if (!kvtop(NULL, lm->mod_base, &paddr, 0)) { > + if (lm->mod_base && !kvtop(NULL, lm->mod_base, &paddr, 0)) { > irregularities++; > break; > } > -- > 2.45.1 > -- > Crash-utility mailing list -- devel(a)lists.crash-utility.osci.io > To unsubscribe send an email to devel-leave(a)lists.crash-utility.osci.io > https://${domain_name}/admin/lists/devel.lists.crash-utility.osci.io/ > Contribution Guidelines: https://github.com/crash-utility/crash/wiki