linux.git/arch/xtensa/kernel/entry.S, branch v5.18

xtensa: clean up kernel exit assembly code

2022-03-19T20:08:41+00:00

Don't use numeric labels for complex branching logic. Mark each branch
with named local label and use them. Rearrange exit back to kernel mode
to avoid conditional label definition.

Signed-off-by: Max Filippov

xtensa: rearrange NMI exit path

2022-03-19T20:08:32+00:00

NMI exit path to userspace should neither check TIF_DB_DISABLED nor call
check_tlb_sanity because NMI shouldn't touch anything related to
userspace. Drop kernel/userspace check in NMI exit path.

Signed-off-by: Max Filippov

xtensa: rename PT_SIZE to PT_KERNEL_SIZE

2022-03-07T20:02:48+00:00

PT_SIZE is used by the xtensa port to designate kernel exception frame
size. In preparation for struct pt_regs size change rename PT_SIZE to
PT_KERNEL_SIZE for clarity and change its definition to always cover
only the kernel exception frame.

Signed-off-by: Max Filippov 
Reviewed-by: Kees Cook

exit/xtensa: In arch/xtensa/entry.S:Linvalid_mask call make_task_dead

2022-01-08T16:46:31+00:00

There have historically been two big uses of do_exit.  The first is
it's design use to be the guts of the exit(2) system call.  The second
use is to terminate a task after something catastrophic has happened
like a NULL pointer in kernel code.  The function make_task_dead
has been added to accomidate the second use.

The call to do_exit in Linvalidmask is clearly not a normal userspace
exit.  As failure handling there are two possible ways to go.
If userspace can trigger the issue force_exit_sig should be called.
Otherwise make_task_dead probably from the implementation of die
is appropriate.

Replace the call of do_exit in Linvalidmask with make_task_dead as
I don't know xtensa and especially xtensa assembly language well
enough to do anything else.

Link: https://lkml.kernel.org/r/YdUmN7n4W5YETUhW@zeniv-ca.linux.org.uk
Suggested-by: Al Viro 
Signed-off-by: "Eric W. Biederman"

xtensa: only build windowed register support code when needed

2021-10-19T05:19:35+00:00

There's no need in window overflow/underflow/alloca exception handlers
or window spill code when neither kernel nor userspace support windowed
registers. Don't build or link it.

Signed-off-by: Max Filippov

xtensa: use register window specific opcodes only when present

2021-10-19T05:19:35+00:00

xtensa core may be configured without register windows support, don't
use register window specific opcodes in that case. Use window register
specific opcodes to initialize hardware or reset core to a known state
regardless of the chosen ABI.

Signed-off-by: Max Filippov

xtensa: implement call0 ABI support in assembly

2021-10-19T05:19:35+00:00

Replace hardcoded register and opcode names with ABI-agnostic macros.
Add register save/restore code where necessary. Conditionalize windowed
only or call0 only code. Add stack initialization matching _switch_to
epilogue to copy_thread.

Signed-off-by: Max Filippov

xtensa: add support for TIF_NOTIFY_SIGNAL

2020-11-12T15:45:56+00:00

Wire up TIF_NOTIFY_SIGNAL handling for xtensa.

Thanks to Max Filippov  for making the asm correct.

Cc: linux-xtensa@linux-xtensa.org
Signed-off-by: Jens Axboe

xtensa: add missing exclusive access state management

2020-07-31T21:15:57+00:00

The result of the s32ex opcode is recorded in the ATOMCTL special
register and must be retrieved with the getex opcode. Context switch
between s32ex and getex may trash the ATOMCTL register and result in
duplicate update or missing update of the atomic variable.
Add atomctl8 field to the struct thread_info and use getex to swap
ATOMCTL bit 8 as a part of context switch.
Clear exclusive access monitor on kernel entry.

Cc: stable@vger.kernel.org
Fixes: f7c34874f04a ("xtensa: add exclusive atomics support")
Signed-off-by: Max Filippov

mm: reorder includes after introduction of linux/pgtable.h

2020-06-09T16:39:13+00:00

The replacement of  with  made the include
of the latter in the middle of asm includes.  Fix this up with the aid of
the below script and manual adjustments here and there.

	import sys
	import re

	if len(sys.argv) is not 3:
	    print "USAGE: %s  " % (sys.argv[0])
	    sys.exit(1)

	hdr_to_move="#include " % sys.argv[2]
	moved = False
	in_hdrs = False

	with open(sys.argv[1], "r") as f:
	    lines = f.readlines()
	    for _line in lines:
		line = _line.rstrip('
')
		if line == hdr_to_move:
		    continue
		if line.startswith("#include 
Signed-off-by: Andrew Morton 
Cc: Arnd Bergmann 
Cc: Borislav Petkov 
Cc: Brian Cain 
Cc: Catalin Marinas 
Cc: Chris Zankel 
Cc: "David S. Miller" 
Cc: Geert Uytterhoeven 
Cc: Greentime Hu 
Cc: Greg Ungerer 
Cc: Guan Xuetao 
Cc: Guo Ren 
Cc: Heiko Carstens 
Cc: Helge Deller 
Cc: Ingo Molnar 
Cc: Ley Foon Tan 
Cc: Mark Salter 
Cc: Matthew Wilcox 
Cc: Matt Turner 
Cc: Max Filippov 
Cc: Michael Ellerman 
Cc: Michal Simek 
Cc: Nick Hu 
Cc: Paul Walmsley 
Cc: Richard Weinberger 
Cc: Rich Felker 
Cc: Russell King 
Cc: Stafford Horne 
Cc: Thomas Bogendoerfer 
Cc: Thomas Gleixner 
Cc: Tony Luck 
Cc: Vincent Chen 
Cc: Vineet Gupta 
Cc: Will Deacon 
Cc: Yoshinori Sato 
Link: http://lkml.kernel.org/r/20200514170327.31389-4-rppt@kernel.org
Signed-off-by: Linus Torvalds