Re: Linux 5.19-rc8

[Guenter Roeck]

On Sun, Jul 24, 2022 at 01:42:18PM -0700, Linus Torvalds wrote:
> As already mentioned last week, this release is one of those "extra
> week of rc" ones, and here we are, with release candidate #8.
> 
> There's nothing really surprising in here - a few smaller fixups for
> the retbleed mess as expected, and the usual random one-liners
> elsewhere.
> 
> The diffstat shows mainly some documentation updates and a couple of
> drivers with bigger fixes (eg the i916 GuC firmware thing), and the
> networking sysctl data-race annotations.
> 
> So it all just makes me go "yeah, I'm happy to have done another rc,
> but there is nothing particularly interesting here". Which is all
> fine. Shortlog appended for the curious among you.
> 
> We'll let this simmer for another week, and please do give it another
> round of testing to make this last week count, ok?
> 

Build results:
	total: 150 pass: 150 fail: 0
Qemu test results:
	total: 489 pass: 489 fail: 0

I still randomly see

BUG: KFENCE: out-of-bounds read in _find_next_bit_le+0x10/0x48

That is not a new problem; I see it with some arm boot tests
whenever KFENCE is enabled. I attached a trace with decoded
symbols below. Maybe someone with more experience than me can
figure out if this is an arm specific problem or a test problem
or a qemu problem.

Guenter

---
test_bitmap: parselist: 14: input is '0-2047:128/256' OK, Time: 11667
==================================================================
BUG: KFENCE: out-of-bounds read in _find_next_bit_le (arch/arm/lib/findbit.S:88)

Out-of-bounds read at 0xef59e000 (4096B right of kfence-#93):
_find_next_bit_le (arch/arm/lib/findbit.S:88)
kfence-#93: 0xef59d000-0xef59dfff, size=4096, cache=kmalloc-4k
allocated by task 1 on cpu 1 at 18.432911s:
test_bitmap_printlist (./include/linux/slab.h:600 lib/test_bitmap.c:452)
test_bitmap_init (lib/test_bitmap.c:883 lib/test_bitmap.c:889)
do_one_initcall (./include/linux/jump_label.h:261 ./include/linux/jump_label.h:271 ./include/trace/events/initcall.h:48 init/main.c:1296)
kernel_init_freeable (init/main.c:1367 init/main.c:1384 init/main.c:1403 init/main.c:1610)
kernel_init (init/main.c:1501)
ret_from_fork (arch/arm/kernel/entry-common.S:149)
 0x0
CPU: 1 PID: 1 Comm: swapper/0 Not tainted 5.19.0-rc8 #1
Hardware name: Samsung Exynos (Flattened Device Tree)
PC is at _find_next_bit_le (arch/arm/lib/findbit.S:88)
LR is at bitmap_list_string.constprop.0 (lib/vsprintf.c:1246)
pc : lr : psr: 20000113
sp : f082dc70  ip : 00000001  fp : 00000001
r10: 00000000  r9 : 0000002d  r8 : ef59d000
r7 : c0e55514  r6 : c2215000  r5 : 00008000  r4 : 00008000
r3 : 845cac12  r2 : 00008001  r1 : 00008000  r0 : ef59d000
Flags: nzCv  IRQs on  FIQs on  Mode SVC_32  ISA ARM  Segment none
Control: 10c5387d  Table: 4000406a  DAC: 00000051
CPU: 1 PID: 1 Comm: swapper/0 Not tainted 5.19.0-rc8 #1
Hardware name: Samsung Exynos (Flattened Device Tree)
unwind_backtrace from show_stack (arch/arm/kernel/traps.c:255)
show_stack from dump_stack_lvl (lib/dump_stack.c:107)
dump_stack_lvl from kfence_report_error (mm/kfence/report.c:262)
kfence_report_error from kfence_handle_page_fault (mm/kfence/core.c:1151)
kfence_handle_page_fault from __do_kernel_fault.part.0 (arch/arm/mm/fault.c:143)
__do_kernel_fault.part.0 from do_page_fault (arch/arm/mm/fault.c:380)
do_page_fault from do_DataAbort (arch/arm/mm/fault.c:539)
do_DataAbort from __dabt_svc (arch/arm/kernel/entry-armv.S:214)
Exception stack(0xf082dc20 to 0xf082dc68)
dc20: ef59d000 00008000 00008001 845cac12 00008000 00008000 c2215000 c0e55514
dc40: ef59d000 0000002d 00000000 00000001 00000001 f082dc70 c0715930 c06ff18c
dc60: 20000113 ffffffff
__dabt_svc from _find_next_bit_le (arch/arm/lib/findbit.S:88)
==================================================================
test_bitmap: bitmap_print_to_pagebuf: input is '0-32767
', Time: 15696250