On Tue, Jan 18, 2022 at 04:03:27PM -0800, Josh Poimboeuf wrote:
> If one of the '__bug_table' asm snippets isn't immediately followed by
> the .L[un]reachable asm, then yeah, it's the same issue.
Found one.
AFAICT, that's the WARN_ON_ONCE(1) catch-all in the default: label of
the switch-case in nf_hook(). That thing is followed by other gunk and
no *reachable label near it.
Damn - that was too good to be true. Gotta love those compilers. :-P
# ./include/linux/netfilter.h:252: WARN_ON_ONCE(1);
#APP
# 252 "./include/linux/netfilter.h" 1
1: .byte 0x0f, 0x0b
.pushsection __bug_table,"aw"
2: .long 1b - 2b # bug_entry::bug_addr
.long .LC5 - 2b # bug_entry::file #
.word 252 # bug_entry::line #
.word 2307 # bug_entry::flags #
.org 2b+12 #
.popsection
# 0 "" 2
#NO_APP
.p2align 4,,3
jmp .L344 #
.L265:
# ./include/linux/netfilter.h:229: hook_head = rcu_dereference(net->nf.hooks_ipv4[hook]);
--
Regards/Gruss,
Boris.
https://people.kernel.org/tglx/notes-about-netiquette
