On Thu, Jan 14, 2021 at 04:41:28PM -0800, Sami Tolvanen wrote: > I can confirm that all the warnings I previously saw are now fixed, > but I'm seeing a few new ones: > > vmlinux.o: warning: objtool: balance_leaf_when_delete()+0x17d4: stack state > mismatch: cfa1=7+192 cfa2=7+176 > vmlinux.o: warning: objtool: internal_move_pointers_items()+0x9f7: stack > state mismatch: cfa1=7+160 cfa2=7+176
These seem legit stack state mismatches (compiler bug). Two code blocks, with different stack sizes, transfer control to the same noreturn block (violating DWARF/ORC expectation that each instruction has a deterministic stack layout). In both cases the noreturn block has a call to __reiserfs_panic(). https://paste.centos.org/view/081cbfc1 https://paste.centos.org/view/265968a6 > vmlinux.o: warning: objtool: strncpy_from_user()+0x181: call to > do_strncpy_from_user() with UACCESS enabled > vmlinux.o: warning: objtool: strnlen_user()+0x12b: call to do_strnlen_user() > with UACCESS enabled It's odd that Clang wouldn't inline these static single-called functions. I could '__always_inline' them, but is this expected behavior? > vmlinux.o: warning: objtool: i915_gem_execbuffer2_ioctl()+0x390: call to > __ubsan_handle_negate_overflow() with UACCESS enabled PeterZ, have you seen this one? https://paste.centos.org/view/b4723113 > vmlinux.o: warning: objtool: .text.snd_trident_free_voice: unexpected end of > section Another weird compiler issue. It generates obviously dead code which jumps off the end of the function: f7: b0 01 mov $0x1,%al f9: 84 c0 test %al,%al fb: 0f 84 79 05 00 00 je 67a <snd_trident_free_voice+0x67a> https://paste.centos.org/view/a1887ae3 -- Josh
