On 6/15/22 08:37, Mark Rutland wrote: > On Wed, Jun 15, 2022 at 03:18:44PM +0300, Ivan T. Ivanov wrote: >> I have run following [1] livepatch tests on kernel build from your repository. >> Overall results looks good, but when I run klp_tc_13.shI there is something which >> I still can not understand completely. It is because of kaslr. >> >> [ 36.817617] livepatch: enabling patch 'klp_tc_13_livepatch' >> [ 36.819602] branch_imm_common: offset out of range >> [ 36.820113] branch_imm_common: offset out of range >> [ 36.820643] ------------[ ftrace bug ]------------ >> [ 36.821172] ftrace failed to modify >> [ 36.821173] [<ffffdde931176804>] orig_do_read_active_livepatch_id+0x4/0xa8 [klp_test_support_mod] >> [ 36.822465] actual: e4:01:00:94 >> [ 36.822821] Updating ftrace call site to call a different ftrace function >> [ 36.823537] ftrace record flags: e4000002 >> [ 36.823953] (2) R >> [ 36.823953] expected tramp: ffffdde96882e224 >> [ 36.824619] ------------[ cut here ]------------ >> [ 36.825125] WARNING: CPU: 0 PID: 950 at kernel/trace/ftrace.c:2085 ftrace_bug+0x98/0x280 >> [ 36.826027] Modules linked in: klp_tc_13_livepatch(OK+) klp_test_support_mod(O) crct10dif_ce >> [ 36.826943] CPU: 0 PID: 950 Comm: insmod Tainted: G O K 5.18.0-rc1-00020-g1ffee6fdcfda #39 >> [ 36.827987] Hardware name: linux,dummy-virt (DT) >> [ 36.828546] pstate: 60400005 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--) >> [ 36.829348] pc : ftrace_bug+0x98/0x280 >> [ 36.829790] lr : ftrace_bug+0x228/0x280 >> [ 36.830224] sp : ffff8000084038e0 >> [ 36.830620] x29: ffff8000084038e0 x28: ffff00000485a920 x27: ffffdde931176804 >> [ 36.831419] x26: ffffdde93117d1a0 x25: ffff00000485a900 x24: ffffdde96aea1000 >> [ 36.832226] x23: 0000000000000000 x22: 0000000000000001 x21: ffffdde96a124da0 >> [ 36.833024] x20: ffff0000045620f0 x19: ffffdde96b54a358 x18: ffffffffffffffff >> [ 36.833818] x17: 5b20386178302f34 x16: 78302b64695f6863 x15: ffffdde96a3078f8 >> [ 36.834621] x14: 0000000000000000 x13: 3432326532383836 x12: ffffdde96ae9b3d8 >> [ 36.835425] x11: 0000000000000001 x10: 0000000000000001 x9 : ffffdde96891305c >> [ 36.836221] x8 : c0000000ffffefff x7 : 0000000000017fe8 x6 : ffffdde96ae83398 >> [ 36.837023] x5 : 0000000000057fa8 x4 : 0000000000000000 x3 : 00000000ffffefff >> [ 36.837836] x2 : e32439832ffb9700 x1 : 0000000000000000 x0 : 0000000000000022 >> [ 36.838635] Call trace: >> [ 36.838923] ftrace_bug+0x98/0x280 >> [ 36.839319] ftrace_replace_code+0xa0/0xb8 >> [ 36.839768] ftrace_modify_all_code+0xc0/0x160 >> [ 36.840273] arch_ftrace_update_code+0x14/0x20 >> [ 36.840780] ftrace_run_update_code+0x24/0x78 >> [ 36.841283] ftrace_startup_enable+0x50/0x60 >> [ 36.841781] ftrace_startup+0xb4/0x178 >> [ 36.842214] register_ftrace_function+0x68/0x88 >> [ 36.842738] klp_patch_object+0x1c8/0x330 >> [ 36.843196] klp_enable_patch+0x468/0x828 > > IIUC that splat specifically is due to ftrace_modify_call() missing module PLT lookups. > > That should be fixed by: > > https://lore.kernel.org/all/20220614080944.1349146-3-mark.rutland@xxxxxxx/ > > I have not looked at the rest of this series (yet). > > Thanks, > Mark. Thank you so much, Mark! I will include this in my patch series until it is upstream. Madhavan
