Re: A native armv7 panic during kyua runs: sys/netinet6/exthdr:exthdr -> Fatal kernel mode data abort: 'Alignment Fault' on read
- Reply: Mark Millard : "Re: A native armv7 panic during kyua runs: sys/netinet6/exthdr:exthdr -> Fatal kernel mode data abort: 'Alignment Fault' on read"
- In reply to: Mark Millard : "Re: A native armv7 panic during kyua runs: sys/netinet6/exthdr:exthdr -> Fatal kernel mode data abort: 'Alignment Fault' on read"
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Date: Sat, 05 Aug 2023 21:40:41 UTC
On Aug 5, 2023, at 14:04, Mark Millard <marklmi@yahoo.com> wrote: > On Aug 5, 2023, at 11:27, Michal Meloun <meloun.michal@gmail.com> wrote: > >> Hi Mark, >> can you please try a this patch? >> https://github.com/strejda/tegra/commit/bd4390c5f6a8b66b2fc83966d4fadb945a19dc23 > > I'll take a stab at testing it. > > But I'll note that description of the patch is somewhat odd: > > QUOTE > Pack IP structures directly used for access packet data. > All structures used to access data in byte buffers shall be marked > as packed. Otherwise, this is undefined behavior - formally on > every platform. > END QUOTE > > __packed (and whatever it might be a macro for) is not part of > any vintage of the C standard, not even as explicitly > implementation defined nor as explicitly undefined. (C23's > "attribute specifier sequence" notation use would give an > implementation defined status as an understand, but not via > explicit identification of the concept of packed in the standard.) > As far as the language is concerned, there is no guarantee that > a code generator will ensure to break things up into aligned > accesses with assembly of the overall value if the members are > not aligned in the first place, __packed or not. Nor does the > language guarantee pack of padding in the layout for __packed. > > Past that, it is toolchain specific if __packed would avoid > unaligned accesses for simple member access notation bytes > yet also avoid having pad bytes. We will see for this context. > (My history suggests a lack of overall uniformity in the > interpretations given to declaring struct's as packed --or > analogous wording for other languages that are not explicit > about it.) > >> I'm sorry, but I don't have the time or energy to fully test it... I only hope the actual patch is much easier than the one listed in PR271759. > [Older history deleted.] No notable change in behavior, I'm afraid . . . sys/netinet6/exthdr:exthdr -> Fatal kernel mode data abort: 'Alignment Fault' on read trapframe: 0xc51fbaa0 FSR=00000001, FAR=daed4476, spsr=60000013 r0 =daf787c0, r1 =c51fbb34, r2 =00000000, r3 =00000000 r4 =00000000, r5 =00000000, r6 =daed4476, r7 =daed4466 r8 =c0965c3c, r9 =00000000, r10=db0e4400, r11=c51fbb60 r12=00000000, ssp=c51fbb30, slr=c0b524c0, pc =c04e8e78 panic: Fatal abort cpuid = 1 time = 1691270886 KDB: stack backtrace: db_trace_self() at db_trace_self pc = 0xc0661824 lr = 0xc007db80 (db_trace_self_wrapper+0x30) sp = 0xc51fb858 fp = 0xc51fb970 db_trace_self_wrapper() at db_trace_self_wrapper+0x30 pc = 0xc007db80 lr = 0xc031a834 (vpanic+0x140) sp = 0xc51fb978 fp = 0xc51fb998 r4 = 0x00000100 r5 = 0x00000000 r6 = 0xc07c5a9a r7 = 0xc0b36e58 vpanic() at vpanic+0x140 pc = 0xc031a834 lr = 0xc031a6f4 (vpanic) sp = 0xc51fb9a0 fp = 0xc51fb9a4 r4 = 0xc51fbaa0 r5 = 0x00000013 r6 = 0xdaed4476 r7 = 0x00000001 r8 = 0x00000001 r9 = 0xdaf787c0 r10 = 0xdaed4476 vpanic() at vpanic pc = 0xc031a6f4 lr = 0xc0686ddc (abort_align) sp = 0xc51fb9ac fp = 0xc51fb9d8 r4 = 0x00000001 r5 = 0x00000001 r6 = 0xdaf787c0 r7 = 0xdaed4476 r8 = 0xc51fb9a4 r9 = 0xc031a6f4 r10 = 0xc51fb9ac abort_align() at abort_align pc = 0xc0686ddc lr = 0xc0686e50 (abort_align+0x74) sp = 0xc51fb9e0 fp = 0xc51fb9f8 r4 = 0x00000013 r10 = 0xdaed4476 abort_align() at abort_align+0x74 pc = 0xc0686e50 lr = 0xc0686aa8 (abort_handler+0x45c) sp = 0xc51fba00 fp = 0xc51fba98 r4 = 0x00000000 r10 = 0xdaed4476 abort_handler() at abort_handler+0x45c pc = 0xc0686aa8 lr = 0xc06640d8 (exception_exit) sp = 0xc51fbaa0 fp = 0xc51fbb60 r4 = 0x00000000 r5 = 0x00000000 r6 = 0xdaed4476 r7 = 0xdaed4466 r8 = 0xc0965c3c r9 = 0x00000000 r10 = 0xdb0e4400 exception_exit() at exception_exit pc = 0xc06640d8 lr = 0xc0b524c0 (__pcpu+0x200) sp = 0xc51fbb30 fp = 0xc51fbb60 r0 = 0xdaf787c0 r1 = 0xc51fbb34 r2 = 0x00000000 r3 = 0x00000000 r4 = 0x00000000 r5 = 0x00000000 r6 = 0xdaed4476 r7 = 0xdaed4466 r8 = 0xc0965c3c r9 = 0x00000000 r10 = 0xdb0e4400 r12 = 0x00000000 in6ifa_ifwithaddr() at in6ifa_ifwithaddr+0x30 pc = 0xc04e8e78 lr = 0xc04fb338 (ip6_input+0xd38) sp = 0xc51fbb68 fp = 0xc51fbc28 r4 = 0xdaed4476 r5 = 0xdaed445e r6 = 0x00000000 r7 = 0xdaed4466 ip6_input() at ip6_input+0xd38 pc = 0xc04fb338 lr = 0xc046d66c (netisr_dispatch_src+0xf8) sp = 0xc51fbc30 fp = 0xc51fbc58 r4 = 0xdaed4400 r5 = 0x00000006 r6 = 0x00000001 r7 = 0xc0b4dd50 r8 = 0xdaf9d900 r9 = 0xdaed4400 r10 = 0x00000086 netisr_dispatch_src() at netisr_dispatch_src+0xf8 pc = 0xc046d66c lr = 0xc04641b0 (ether_demux+0x18c) sp = 0xc51fbc60 fp = 0xc51fbc78 r4 = 0x00000006 r5 = 0x00001201 r6 = 0xdb0e4400 r7 = 0x000000ff r8 = 0xdaf9d900 r9 = 0xdaed4400 r10 = 0x00000086 ether_demux() at ether_demux+0x18c pc = 0xc04641b0 lr = 0xc0465880 (ether_nh_input+0x490) sp = 0xc51fbc80 fp = 0xc51fbce0 r4 = 0xdb0e4400 r5 = 0xdaed4400 r6 = 0xdaed4450 r10 = 0x00000086 ether_nh_input() at ether_nh_input+0x490 pc = 0xc0465880 lr = 0xc046d66c (netisr_dispatch_src+0xf8) sp = 0xc51fbce8 fp = 0xc51fbd10 r4 = 0xdaed4400 r5 = 0x00000005 r6 = 0x00000003 r7 = 0xc0b4dd30 r8 = 0xdaf9d900 r9 = 0xdaed4400 r10 = 0xc098f58f netisr_dispatch_src() at netisr_dispatch_src+0xf8 pc = 0xc046d66c lr = 0xc04645c4 (ether_input+0x50) sp = 0xc51fbd18 fp = 0xc51fbd48 r4 = 0xdaed4400 r5 = 0x00000000 r6 = 0x00008803 r7 = 0x00000000 r8 = 0xdaf9d900 r9 = 0xdaed4400 r10 = 0xc098f58f ether_input() at ether_input+0x50 pc = 0xc04645c4 lr = 0xdffb3f08 ($a.10+0x108) sp = 0xc51fbd50 fp = 0xc51fbd78 r4 = 0xdb0e4400 r5 = 0xdaff4000 r6 = 0xdaff4010 r7 = 0x00000000 r8 = 0x00000000 r10 = 0xc098f58f $a.10() at $a.10+0x108 pc = 0xdffb3f08 lr = 0xc038cb2c (taskqueue_run_locked+0x1c4) sp = 0xc51fbd80 fp = 0xc51fbdd8 r4 = 0xdaff2100 r5 = 0xdaff402c r6 = 0xdaff2150 r7 = 0x00000001 r8 = 0x00000000 r9 = 0xc51fbd90 r10 = 0x00000001 taskqueue_run_locked() at taskqueue_run_locked+0x1c4 pc = 0xc038cb2c lr = 0xc038e4e4 (taskqueue_thread_loop+0x1b0) sp = 0xc51fbde0 fp = 0xc51fbe10 r4 = 0xdaff2100 r5 = 0xdaff2140 r6 = 0xc07b18c4 r7 = 0x00000000 r8 = 0xc098f58f r9 = 0x00000100 r10 = 0xc0b268a0 taskqueue_thread_loop() at taskqueue_thread_loop+0x1b0 pc = 0xc038e4e4 lr = 0xc02cdf0c (fork_exit+0xc0) sp = 0xc51fbe18 fp = 0xc51fbe38 r4 = 0xdaf787c0 r5 = 0xc0b264e0 r6 = 0xc038e334 r7 = 0xdffc4f54 r8 = 0xc51fbe40 r9 = 0xc098f591 fork_exit() at fork_exit+0xc0 pc = 0xc02cdf0c lr = 0xc066406c (swi_exit) sp = 0xc51fbe40 fp = 0x00000000 r4 = 0xc038e334 r5 = 0xdffc4f54 r6 = 0xc0b48d84 r7 = 0xd73bd3e0 r8 = 0x00000001 r10 = 0xc0b268a0 swi_exit() at swi_exit pc = 0xc066406c lr = 0xc066406c (swi_exit) sp = 0xc51fbe40 fp = 0x00000000 KDB: enter: panic [ thread pid 0 tid 100226 ] I've just restored the sources involved but still have the .diff I that got via github. === Mark Millard marklmi at yahoo.com