Re: Armv7 panic on -current, rpi2 buildworld

On Feb 14, 2023, at 20:16, Warner Losh <imp@bsdimp.com> wrote:

> Sorry to top post... what program was dumping core? Looks like a too strict assert

Just a possible point, given recent kernel floating
point work:

Because of Bob's note, I tried to do a typical build
and test of some benchmark programs that I sometimes
use that involve floating point in some of the
programs, some use with multithreading involved. (As
FreeBSD and g++ progress I tend to do this once and
a while, not as often on armv7 as on aarch64.)

On armv7, I now get a message about a failure of an
internal cross-check, which also leads to the program
being stopped early. The messaging from run to run
varies what the failure is, but the runs should not
vary and should not fail the cross-checks --and
previously did not, including when I last tried armv7.
(Not recently.)

For the specific example failure, the initial serial
(single thread) test with float involved works but the
following multi-thread test in the same program fails
and causes the program to stop when it notices there
is a problem.

The programs that do not test floating point do not
fail. These can involve floating point outside the
algorithm benchmarked, but with no multi-threading
involved for such and no floating point based cross-
checks involved.

At this point it is far from obvious to me how I
would trackdown the specifics of what leads to the
failed cross-checks. But the above is suggestive of
there being problems for armv7 handling of saving
and restoring floating point context for
multi-threading. I've no clue if such are limited
to the floating point values or not.

> Warner
> 
> On Tue, Feb 14, 2023, 7:57 PM bob prohaska <fbsd@www.zefox.net> wrote:
> Building world on an RPi2 armv7, buildworld stopped with
> bob@www:/usr/src % panic: Called fill_fpregs while the kernel is using the VFP
> cpuid = 0
> time = 1676427410
> KDB: stack backtrace:
> db_trace_self() at db_trace_self
>          pc = 0xc05e8160  lr = 0xc007aa04 (db_trace_self_wrapper+0x30)
>          sp = 0xde2c5790  fp = 0xde2c58a8
> db_trace_self_wrapper() at db_trace_self_wrapper+0x30
>          pc = 0xc007aa04  lr = 0xc02e9c54 (vpanic+0x140)
>          sp = 0xde2c58b0  fp = 0xde2c58d0
>          r4 = 0x00000100  r5 = 0x00000000
>          r6 = 0xc07372ef  r7 = 0xc0b13968
> vpanic() at vpanic+0x140
>          pc = 0xc02e9c54  lr = 0xc02e9a34 (dump_savectx)
>          sp = 0xde2c58d8  fp = 0xde2c58dc
>          r4 = 0xd70c8600  r5 = 0xde2c5e90
>          r6 = 0xc3398090  r7 = 0xe0cfc440
>          r8 = 0xc3398080  r9 = 0xd70c8600
>         r10 = 0xde2c5960
> dump_savectx() at dump_savectx
>          pc = 0xc02e9a34  lr = 0xc05f51dc (set_regs)
>          sp = 0xde2c58e4  fp = 0xde2c58f8
> set_regs() at set_regs
>          pc = 0xc05f51dc  lr = 0xc026f8f0 (elf32_get_fpregset+0x2c)
>          sp = 0xde2c5900  fp = 0xde2c5908
>          r4 = 0xc3398090  r5 = 0xc026f8c4
> elf32_get_fpregset() at elf32_get_fpregset+0x2c
>          pc = 0xc026f8f0  lr = 0xc026d848 (elf32_coredump+0x308)
>          sp = 0xde2c5910  fp = 0xde2c5988
>          r4 = 0xc0902a7c r10 = 0xde2c5960
> elf32_coredump() at elf32_coredump+0x308
>          pc = 0xc026d848  lr = 0xc02eea74 (sigexit+0xce0)
>          sp = 0xde2c5990  fp = 0xde2c5cf8
>          r4 = 0x0000004e  r5 = 0xdf580b60
>          r6 = 0xdf580a78  r7 = 0xc026d540
>          r8 = 0xdddcb2bc  r9 = 0xdf580ad4
>         r10 = 0x00000000
> sigexit() at sigexit+0xce0
>          pc = 0xc02eea74  lr = 0xc02ef36c (postsig+0x128)
>          sp = 0xde2c5d00  fp = 0xde2c5d88
>          r4 = 0x00000006  r5 = 0xdd43fba0
>          r6 = 0xde2c5d20  r7 = 0xde2c5d18
>          r8 = 0xdddcb1f8  r9 = 0xdf3d9ab8
>         r10 = 0x00000005
> postsig() at postsig+0x128
>          pc = 0xc02ef36c  lr = 0xc02f316c (ast_sig+0x11c)
>          sp = 0xde2c5d90  fp = 0xde2c5e08
>          r4 = 0xdd43fba0  r5 = 0xdddcb2bc
>          r6 = 0xc0734d22  r7 = 0x00000000
>          r8 = 0xdddcb1f8  r9 = 0x00000ab8
>         r10 = 0x22530384
> ast_sig() at ast_sig+0x11c
>          pc = 0xc02f316c  lr = 0xc035444c (ast_handler+0xe0)
>          sp = 0xde2c5e10  fp = 0xde2c5e28
>          r4 = 0xde2c5e40  r5 = 0x0000000e
>          r6 = 0x00004000  r7 = 0xc096b59c
>          r8 = 0xdd43fba0  r9 = 0x00000001
> ast_handler() at ast_handler+0xe0
>          pc = 0xc035444c  lr = 0xc035435c (ast+0x20)
>          sp = 0xde2c5e30  fp = 0xde2c5e38
>          r4 = 0xde2c5e40  r5 = 0xdd43fba0
>          r6 = 0x00000000  r7 = 0x000001b1
>          r8 = 0x22c4b500  r9 = 0x00000000
> ast() at ast+0x20
>          pc = 0xc035435c  lr = 0xc05eaa88 (swi_exit+0x3c)
>          sp = 0xde2c5e40  fp = 0xbb9fbe38
>          r4 = 0x60000013  r5 = 0xdd43fba0
> swi_exit() at swi_exit+0x3c
>          pc = 0xc05eaa88  lr = 0xc05eaa88 (swi_exit+0x3c)
>          sp = 0xde2c5e40  fp = 0xbb9fbe38
> KDB: enter: panic
> [ thread pid 81621 tid 101111 ]
> Stopped at      kdb_enter+0x54: ldrb    r15, [r15, r15, ror r15]!
> db> bt
> Tracing pid 81621 tid 101111 td 0xdd43fba0
> db_trace_self() at db_trace_self
>          pc = 0xc05e8160  lr = 0xc00774a0 (db_stack_trace+0x140)
>          sp = 0xde2c55d8  fp = 0xde2c55f0
> db_stack_trace() at db_stack_trace+0x140
>          pc = 0xc00774a0  lr = 0xc00770f0 (db_command+0x310)
>          sp = 0xde2c55f8  fp = 0xde2c56a0
>          r4 = 0xc0745722  r5 = 0x00000062
>          r6 = 0x00000000 r10 = 0x00000000
> db_command() at db_command+0x310
>          pc = 0xc00770f0  lr = 0xc0076db8 (db_command_loop+0x64)
>          sp = 0xde2c56a8  fp = 0xde2c56b8
>          r4 = 0xc07ac186  r5 = 0xc07ab7fe
>          r6 = 0xc0986f5c  r7 = 0xc0b13968
>          r8 = 0xc0b23738  r9 = 0x00000000
>         r10 = 0x00000001
> db_command_loop() at db_command_loop+0x64
>          pc = 0xc0076db8  lr = 0xc007ab88 (db_trap+0x128)
>          sp = 0xde2c56c0  fp = 0xde2c57d8
>          r4 = 0x00000000  r5 = 0xc0986f50
>          r6 = 0xc0b23758 r10 = 0x00000001
> db_trap() at db_trap+0x128
>          pc = 0xc007ab88  lr = 0xc033bb84 (kdb_trap+0x258)
>          sp = 0xde2c57e0  fp = 0xde2c5808
>          r4 = 0xc078390c  r5 = 0xc08d5270
>          r6 = 0xc0b23758  r7 = 0xc0b13968
> kdb_trap() at kdb_trap+0x258
>          pc = 0xc033bb84  lr = 0xc05eaab8 (exception_exit)
>          sp = 0xde2c5810  fp = 0xde2c58a8
>          r4 = 0x200000d3  r5 = 0x00000000
>          r6 = 0xc07372ef  r7 = 0xc0b13968
>          r8 = 0xc093fa0c  r9 = 0xde2c58e4
>         r10 = 0xc0b13a68
> exception_exit() at exception_exit
>          pc = 0xc05eaab8  lr = 0xc033b044 (kdb_enter+0x50)
>          sp = 0xde2c58a0  fp = 0xde2c58a8
>          r0 = 0x00000000  r1 = 0x00000001
>          r2 = 0x00000012  r3 = 0x00000000
>          r4 = 0xc0b23748  r5 = 0x00000000
>          r6 = 0xc07372ef  r7 = 0xc0b13968
>          r8 = 0xc093fa0c  r9 = 0xde2c58e4
>         r10 = 0xc0b13a68 r12 = 0x00000000
> kdb_enter() at kdb_enter+0x58
>          pc = 0xc033b04c  lr = 0xc02e9ca0 (vpanic+0x18c)
>          sp = 0xde2c58b0  fp = 0xde2c58d0
>          r4 = 0x00000100 r10 = 0xc0b13a68
> vpanic() at vpanic+0x18c
>          pc = 0xc02e9ca0  lr = 0xc02e9a34 (dump_savectx)
>          sp = 0xde2c58d8  fp = 0xde2c58dc
>          r4 = 0xd70c8600  r5 = 0xde2c5e90
>          r6 = 0xc3398090  r7 = 0xe0cfc440
>          r8 = 0xc3398080  r9 = 0xd70c8600
>         r10 = 0xde2c5960
> dump_savectx() at dump_savectx
>          pc = 0xc02e9a34  lr = 0xc05f51dc (set_regs)
>          sp = 0xde2c58e4  fp = 0xde2c58f8
> set_regs() at set_regs
>          pc = 0xc05f51dc  lr = 0xc026f8f0 (elf32_get_fpregset+0x2c)
>          sp = 0xde2c5900  fp = 0xde2c5908
>          r4 = 0xc3398090  r5 = 0xc026f8c4
> elf32_get_fpregset() at elf32_get_fpregset+0x2c
>          pc = 0xc026f8f0  lr = 0xc026d848 (elf32_coredump+0x308)
>          sp = 0xde2c5910  fp = 0xde2c5988
>          r4 = 0xc0902a7c r10 = 0xde2c5960
> elf32_coredump() at elf32_coredump+0x308
>          pc = 0xc026d848  lr = 0xc02eea74 (sigexit+0xce0)
>          sp = 0xde2c5990  fp = 0xde2c5cf8
>          r4 = 0x0000004e  r5 = 0xdf580b60
>          r6 = 0xdf580a78  r7 = 0xc026d540
>          r8 = 0xdddcb2bc  r9 = 0xdf580ad4
>         r10 = 0x00000000
> sigexit() at sigexit+0xce0
>          pc = 0xc02eea74  lr = 0xc02ef36c (postsig+0x128)
>          sp = 0xde2c5d00  fp = 0xde2c5d88
>          r4 = 0x00000006  r5 = 0xdd43fba0
>          r6 = 0xde2c5d20  r7 = 0xde2c5d18
>          r8 = 0xdddcb1f8  r9 = 0xdf3d9ab8
>         r10 = 0x00000005
> postsig() at postsig+0x128
>          pc = 0xc02ef36c  lr = 0xc02f316c (ast_sig+0x11c)
>          sp = 0xde2c5d90  fp = 0xde2c5e08
>          r4 = 0xdd43fba0  r5 = 0xdddcb2bc
>          r6 = 0xc0734d22  r7 = 0x00000000
>          r8 = 0xdddcb1f8  r9 = 0x00000ab8
>         r10 = 0x22530384
> ast_sig() at ast_sig+0x11c
>          pc = 0xc02f316c  lr = 0xc035444c (ast_handler+0xe0)
>          sp = 0xde2c5e10  fp = 0xde2c5e28
>          r4 = 0xde2c5e40  r5 = 0x0000000e
>          r6 = 0x00004000  r7 = 0xc096b59c
>          r8 = 0xdd43fba0  r9 = 0x00000001
> ast_handler() at ast_handler+0xe0
>          pc = 0xc035444c  lr = 0xc035435c (ast+0x20)
>          sp = 0xde2c5e30  fp = 0xde2c5e38
>          r4 = 0xde2c5e40  r5 = 0xdd43fba0
>          r6 = 0x00000000  r7 = 0x000001b1
>          r8 = 0x22c4b500  r9 = 0x00000000
> ast() at ast+0x20
>          pc = 0xc035435c  lr = 0xc05eaa88 (swi_exit+0x3c)
>          sp = 0xde2c5e40  fp = 0xbb9fbe38
>          r4 = 0x60000013  r5 = 0xdd43fba0
> swi_exit() at swi_exit+0x3c
>          pc = 0xc05eaa88  lr = 0xc05eaa88 (swi_exit+0x3c)
>          sp = 0xde2c5e40  fp = 0xbb9fbe38
> db> 
> 
> The machine was last updated about a week ago, the
> sources were updated earlier today. This panic is
> new to me.
> 
> Thanks for reading,
> 
> bob prohaska
> 
> 


===
Mark Millard
marklmi at yahoo.com