| Message ID | 20210107001225.3063163-1-vgupta@synopsys.com |
|---|---|
| State | New |
| Headers | show |
| Series | ARC: unbork 5.11 bootup: fix snafu in _TIF_NOTIFY_SIGNAL handling | expand |
On 1/6/21 5:12 PM, Vineet Gupta wrote: > Linux 5.11.rcX was failing to boot on ARC HSDK board. Turns out we have > a couple of issues, this being the first one, and I'm to blame as I > didn't pay attention during review. > > TIF_NOTIFY_SIGNAL support requires checking multiple TIF_* bits in > kernel return code path. Old code only needed to check a single bit so > BBIT0 <TIF_SIGPENDING> worked. New code needs to check multiple bits so > AND <bit-mask> instruction. So needs to use bit mask variant _TIF_SIGPENDING Sorry about that, my arc asm isn't that strong :-) Thanks for fixing it.
diff --git a/arch/arc/kernel/entry.S b/arch/arc/kernel/entry.S index 1f5308abf36d..1743506081da 100644 --- a/arch/arc/kernel/entry.S +++ b/arch/arc/kernel/entry.S @@ -307,7 +307,7 @@ resume_user_mode_begin: mov r0, sp ; pt_regs for arg to do_signal()/do_notify_resume() GET_CURR_THR_INFO_FLAGS r9 - and.f 0, r9, TIF_SIGPENDING|TIF_NOTIFY_SIGNAL + and.f 0, r9, _TIF_SIGPENDING|_TIF_NOTIFY_SIGNAL bz .Lchk_notify_resume ; Normal Trap/IRQ entry only saves Scratch (caller-saved) regs
Linux 5.11.rcX was failing to boot on ARC HSDK board. Turns out we have a couple of issues, this being the first one, and I'm to blame as I didn't pay attention during review. TIF_NOTIFY_SIGNAL support requires checking multiple TIF_* bits in kernel return code path. Old code only needed to check a single bit so BBIT0 <TIF_SIGPENDING> worked. New code needs to check multiple bits so AND <bit-mask> instruction. So needs to use bit mask variant _TIF_SIGPENDING Cc: Jens Axboe <axboe@kernel.dk> Fixes: 53855e12588743ea128 ("arc: add support for TIF_NOTIFY_SIGNAL") Link: https://github.com/foss-for-synopsys-dwc-arc-processors/linux/issues/34 Signed-off-by: Vineet Gupta <vgupta@synopsys.com> --- arch/arc/kernel/entry.S | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)