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linux/arch/sparc/kernel/wof.S
Greg Kroah-Hartman b24413180f License cleanup: add SPDX GPL-2.0 license identifier to files with no license 
Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.

By default all files without license information are under the default
license of the kernel, which is GPL version 2.

Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier.  The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.

This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.

How this work was done:

Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
 - file had no licensing information it it.
 - file was a */uapi/* one with no licensing information in it,
 - file was a */uapi/* one with existing licensing information,

Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.

The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne.  Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.

The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed.  Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.

Criteria used to select files for SPDX license identifier tagging was:
 - Files considered eligible had to be source code files.
 - Make and config files were included as candidates if they contained >5
   lines of source
 - File already had some variant of a license header in it (even if <5
   lines).

All documentation files were explicitly excluded.

The following heuristics were used to determine which SPDX license
identifiers to apply.

 - when both scanners couldn't find any license traces, file was
   considered to have no license information in it, and the top level
   COPYING file license applied.

   For non */uapi/* files that summary was:

   SPDX license identifier                            # files
   ---------------------------------------------------|-------
   GPL-2.0                                              11139

   and resulted in the first patch in this series.

   If that file was a */uapi/* path one, it was "GPL-2.0 WITH
   Linux-syscall-note" otherwise it was "GPL-2.0".  Results of that was:

   SPDX license identifier                            # files
   ---------------------------------------------------|-------
   GPL-2.0 WITH Linux-syscall-note                        930

   and resulted in the second patch in this series.

 - if a file had some form of licensing information in it, and was one
   of the */uapi/* ones, it was denoted with the Linux-syscall-note if
   any GPL family license was found in the file or had no licensing in
   it (per prior point).  Results summary:

   SPDX license identifier                            # files
   ---------------------------------------------------|------
   GPL-2.0 WITH Linux-syscall-note                       270
   GPL-2.0+ WITH Linux-syscall-note                      169
   ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause)    21
   ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause)    17
   LGPL-2.1+ WITH Linux-syscall-note                      15
   GPL-1.0+ WITH Linux-syscall-note                       14
   ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause)    5
   LGPL-2.0+ WITH Linux-syscall-note                       4
   LGPL-2.1 WITH Linux-syscall-note                        3
   ((GPL-2.0 WITH Linux-syscall-note) OR MIT)              3
   ((GPL-2.0 WITH Linux-syscall-note) AND MIT)             1

   and that resulted in the third patch in this series.

 - when the two scanners agreed on the detected license(s), that became
   the concluded license(s).

 - when there was disagreement between the two scanners (one detected a
   license but the other didn't, or they both detected different
   licenses) a manual inspection of the file occurred.

 - In most cases a manual inspection of the information in the file
   resulted in a clear resolution of the license that should apply (and
   which scanner probably needed to revisit its heuristics).

 - When it was not immediately clear, the license identifier was
   confirmed with lawyers working with the Linux Foundation.

 - If there was any question as to the appropriate license identifier,
   the file was flagged for further research and to be revisited later
   in time.

In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.

Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights.  The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.

Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.

In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.

Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
 - a full scancode scan run, collecting the matched texts, detected
   license ids and scores
 - reviewing anything where there was a license detected (about 500+
   files) to ensure that the applied SPDX license was correct
 - reviewing anything where there was no detection but the patch license
   was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
   SPDX license was correct

This produced a worksheet with 20 files needing minor correction.  This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.

These .csv files were then reviewed by Greg.  Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected.  This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.)  Finally Greg ran the script using the .csv files to
generate the patches.

Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-02 11:10:55 +01:00

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/* SPDX-License-Identifier: GPL-2.0 */
/*
* wof.S: Sparc window overflow handler.
*
* Copyright (C) 1995 David S. Miller (davem@caip.rutgers.edu)
*/
#include <asm/contregs.h>
#include <asm/page.h>
#include <asm/ptrace.h>
#include <asm/psr.h>
#include <asm/smp.h>
#include <asm/asi.h>
#include <asm/winmacro.h>
#include <asm/asmmacro.h>
#include <asm/thread_info.h>
/* WARNING: This routine is hairy and _very_ complicated, but it
* must be as fast as possible as it handles the allocation
* of register windows to the user and kernel. If you touch
* this code be _very_ careful as many other pieces of the
* kernel depend upon how this code behaves. You have been
* duly warned...
*/
/* We define macro's for registers which have a fixed
* meaning throughout this entire routine. The 'T' in
* the comments mean that the register can only be
* accessed when in the 'trap' window, 'G' means
* accessible in any window. Do not change these registers
* after they have been set, until you are ready to return
* from the trap.
*/
#define t_psr l0 /* %psr at trap time T */
#define t_pc l1 /* PC for trap return T */
#define t_npc l2 /* NPC for trap return T */
#define t_wim l3 /* %wim at trap time T */
#define saved_g5 l5 /* Global save register T */
#define saved_g6 l6 /* Global save register T */
#define curptr g6 /* Gets set to 'current' then stays G */
/* Now registers whose values can change within the handler. */
#define twin_tmp l4 /* Temp reg, only usable in trap window T */
#define glob_tmp g5 /* Global temporary reg, usable anywhere G */
.text
.align 4
/* BEGINNING OF PATCH INSTRUCTIONS */
/* On a 7-window Sparc the boot code patches spnwin_*
* instructions with the following ones.
*/
.globl spnwin_patch1_7win, spnwin_patch2_7win, spnwin_patch3_7win
spnwin_patch1_7win: sll %t_wim, 6, %glob_tmp
spnwin_patch2_7win: and %glob_tmp, 0x7f, %glob_tmp
spnwin_patch3_7win: and %twin_tmp, 0x7f, %twin_tmp
/* END OF PATCH INSTRUCTIONS */
/* The trap entry point has done the following:
*
* rd %psr, %l0
* rd %wim, %l3
* b spill_window_entry
* andcc %l0, PSR_PS, %g0
*/
/* Datum current_thread_info->uwinmask contains at all times a bitmask
* where if any user windows are active, at least one bit will
* be set in to mask. If no user windows are active, the bitmask
* will be all zeroes.
*/
.globl spill_window_entry
.globl spnwin_patch1, spnwin_patch2, spnwin_patch3
spill_window_entry:
/* LOCATION: Trap Window */
mov %g5, %saved_g5 ! save away global temp register
mov %g6, %saved_g6 ! save away 'current' ptr register
/* Compute what the new %wim will be if we save the
* window properly in this trap handler.
*
* newwim = ((%wim>>1) | (%wim<<(nwindows - 1)));
*/
srl %t_wim, 0x1, %twin_tmp
spnwin_patch1: sll %t_wim, 7, %glob_tmp
or %glob_tmp, %twin_tmp, %glob_tmp
spnwin_patch2: and %glob_tmp, 0xff, %glob_tmp
/* The trap entry point has set the condition codes
* up for us to see if this is from user or kernel.
* Get the load of 'curptr' out of the way.
*/
LOAD_CURRENT(curptr, twin_tmp)
andcc %t_psr, PSR_PS, %g0
be,a spwin_fromuser ! all user wins, branch
save %g0, %g0, %g0 ! Go where saving will occur
/* See if any user windows are active in the set. */
ld [%curptr + TI_UWINMASK], %twin_tmp ! grab win mask
orcc %g0, %twin_tmp, %g0 ! check for set bits
bne spwin_exist_uwins ! yep, there are some
andn %twin_tmp, %glob_tmp, %twin_tmp ! compute new uwinmask
/* Save into the window which must be saved and do it.
* Basically if we are here, this means that we trapped
* from kernel mode with only kernel windows in the register
* file.
*/
save %g0, %g0, %g0 ! save into the window to stash away
wr %glob_tmp, 0x0, %wim ! set new %wim, this is safe now
spwin_no_userwins_from_kernel:
/* LOCATION: Window to be saved */
STORE_WINDOW(sp) ! stash the window
restore %g0, %g0, %g0 ! go back into trap window
/* LOCATION: Trap window */
mov %saved_g5, %g5 ! restore %glob_tmp
mov %saved_g6, %g6 ! restore %curptr
wr %t_psr, 0x0, %psr ! restore condition codes in %psr
WRITE_PAUSE ! waste some time
jmp %t_pc ! Return from trap
rett %t_npc ! we are done
spwin_exist_uwins:
/* LOCATION: Trap window */
/* Wow, user windows have to be dealt with, this is dirty
* and messy as all hell. And difficult to follow if you
* are approaching the infamous register window trap handling
* problem for the first time. DON'T LOOK!
*
* Note that how the execution path works out, the new %wim
* will be left for us in the global temporary register,
* %glob_tmp. We cannot set the new %wim first because we
* need to save into the appropriate window without inducing
* a trap (traps are off, we'd get a watchdog wheee)...
* But first, store the new user window mask calculated
* above.
*/
st %twin_tmp, [%curptr + TI_UWINMASK]
save %g0, %g0, %g0 ! Go to where the saving will occur
spwin_fromuser:
/* LOCATION: Window to be saved */
wr %glob_tmp, 0x0, %wim ! Now it is safe to set new %wim
/* LOCATION: Window to be saved */
/* This instruction branches to a routine which will check
* to validity of the users stack pointer by whatever means
* are necessary. This means that this is architecture
* specific and thus this branch instruction will need to
* be patched at boot time once the machine type is known.
* This routine _shall not_ touch %curptr under any
* circumstances whatsoever! It will branch back to the
* label 'spwin_good_ustack' if the stack is ok but still
* needs to be dumped (SRMMU for instance will not need to
* do this) or 'spwin_finish_up' if the stack is ok and the
* registers have already been saved. If the stack is found
* to be bogus for some reason the routine shall branch to
* the label 'spwin_user_stack_is_bolixed' which will take
* care of things at that point.
*/
b spwin_srmmu_stackchk
andcc %sp, 0x7, %g0
spwin_good_ustack:
/* LOCATION: Window to be saved */
/* The users stack is ok and we can safely save it at
* %sp.
*/
STORE_WINDOW(sp)
spwin_finish_up:
restore %g0, %g0, %g0 /* Back to trap window. */
/* LOCATION: Trap window */
/* We have spilled successfully, and we have properly stored
* the appropriate window onto the stack.
*/
/* Restore saved globals */
mov %saved_g5, %g5
mov %saved_g6, %g6
wr %t_psr, 0x0, %psr
WRITE_PAUSE
jmp %t_pc
rett %t_npc
spwin_user_stack_is_bolixed:
/* LOCATION: Window to be saved */
/* Wheee, user has trashed his/her stack. We have to decide
* how to proceed based upon whether we came from kernel mode
* or not. If we came from kernel mode, toss the window into
* a special buffer and proceed, the kernel _needs_ a window
* and we could be in an interrupt handler so timing is crucial.
* If we came from user land we build a full stack frame and call
* c-code to gun down the process.
*/
rd %psr, %glob_tmp
andcc %glob_tmp, PSR_PS, %g0
bne spwin_bad_ustack_from_kernel
nop
/* Oh well, throw this one window into the per-task window
* buffer, the first one.
*/
st %sp, [%curptr + TI_RWIN_SPTRS]
STORE_WINDOW(curptr + TI_REG_WINDOW)
restore %g0, %g0, %g0
/* LOCATION: Trap Window */
/* Back in the trap window, update winbuffer save count. */
mov 1, %twin_tmp
st %twin_tmp, [%curptr + TI_W_SAVED]
/* Compute new user window mask. What we are basically
* doing is taking two windows, the invalid one at trap
* time and the one we attempted to throw onto the users
* stack, and saying that everything else is an ok user
* window. umask = ((~(%t_wim | %wim)) & valid_wim_bits)
*/
rd %wim, %twin_tmp
or %twin_tmp, %t_wim, %twin_tmp
not %twin_tmp
spnwin_patch3: and %twin_tmp, 0xff, %twin_tmp ! patched on 7win Sparcs
st %twin_tmp, [%curptr + TI_UWINMASK]
#define STACK_OFFSET (THREAD_SIZE - TRACEREG_SZ - STACKFRAME_SZ)
sethi %hi(STACK_OFFSET), %sp
or %sp, %lo(STACK_OFFSET), %sp
add %curptr, %sp, %sp
/* Restore the saved globals and build a pt_regs frame. */
mov %saved_g5, %g5
mov %saved_g6, %g6
STORE_PT_ALL(sp, t_psr, t_pc, t_npc, g1)
sethi %hi(STACK_OFFSET), %g6
or %g6, %lo(STACK_OFFSET), %g6
sub %sp, %g6, %g6 ! curptr
/* Turn on traps and call c-code to deal with it. */
wr %t_psr, PSR_ET, %psr
nop
call window_overflow_fault
nop
/* Return from trap if C-code actually fixes things, if it
* doesn't then we never get this far as the process will
* be given the look of death from Commander Peanut.
*/
b ret_trap_entry
clr %l6
spwin_bad_ustack_from_kernel:
/* LOCATION: Window to be saved */
/* The kernel provoked a spill window trap, but the window we
* need to save is a user one and the process has trashed its
* stack pointer. We need to be quick, so we throw it into
* a per-process window buffer until we can properly handle
* this later on.
*/
SAVE_BOLIXED_USER_STACK(curptr, glob_tmp)
restore %g0, %g0, %g0
/* LOCATION: Trap window */
/* Restore globals, condition codes in the %psr and
* return from trap. Note, restoring %g6 when returning
* to kernel mode is not necessarily these days. ;-)
*/
mov %saved_g5, %g5
mov %saved_g6, %g6
wr %t_psr, 0x0, %psr
WRITE_PAUSE
jmp %t_pc
rett %t_npc
/* Undefine the register macros which would only cause trouble
* if used below. This helps find 'stupid' coding errors that
* produce 'odd' behavior. The routines below are allowed to
* make usage of glob_tmp and t_psr so we leave them defined.
*/
#undef twin_tmp
#undef curptr
#undef t_pc
#undef t_npc
#undef t_wim
#undef saved_g5
#undef saved_g6
/* Now come the per-architecture window overflow stack checking routines.
* As noted above %curptr cannot be touched by this routine at all.
*/
/* This is a generic SRMMU routine. As far as I know this
* works for all current v8/srmmu implementations, we'll
* see...
*/
.globl spwin_srmmu_stackchk
spwin_srmmu_stackchk:
/* LOCATION: Window to be saved on the stack */
/* Because of SMP concerns and speed we play a trick.
* We disable fault traps in the MMU control register,
* Execute the stores, then check the fault registers
* to see what happens. I can hear Linus now
* "disgusting... broken hardware...".
*
* But first, check to see if the users stack has ended
* up in kernel vma, then we would succeed for the 'wrong'
* reason... ;( Note that the 'sethi' below assumes the
* kernel is page aligned, which should always be the case.
*/
/* Check results of callers andcc %sp, 0x7, %g0 */
bne spwin_user_stack_is_bolixed
sethi %hi(PAGE_OFFSET), %glob_tmp
cmp %glob_tmp, %sp
bleu spwin_user_stack_is_bolixed
mov AC_M_SFSR, %glob_tmp
/* Clear the fault status and turn on the no_fault bit. */
LEON_PI(lda [%glob_tmp] ASI_LEON_MMUREGS, %g0) ! eat SFSR
SUN_PI_(lda [%glob_tmp] ASI_M_MMUREGS, %g0) ! eat SFSR
LEON_PI(lda [%g0] ASI_LEON_MMUREGS, %glob_tmp) ! read MMU control
SUN_PI_(lda [%g0] ASI_M_MMUREGS, %glob_tmp) ! read MMU control
or %glob_tmp, 0x2, %glob_tmp ! or in no_fault bit
LEON_PI(sta %glob_tmp, [%g0] ASI_LEON_MMUREGS) ! set it
SUN_PI_(sta %glob_tmp, [%g0] ASI_M_MMUREGS) ! set it
/* Dump the registers and cross fingers. */
STORE_WINDOW(sp)
/* Clear the no_fault bit and check the status. */
andn %glob_tmp, 0x2, %glob_tmp
LEON_PI(sta %glob_tmp, [%g0] ASI_LEON_MMUREGS)
SUN_PI_(sta %glob_tmp, [%g0] ASI_M_MMUREGS)
mov AC_M_SFAR, %glob_tmp
LEON_PI(lda [%glob_tmp] ASI_LEON_MMUREGS, %g0)
SUN_PI_(lda [%glob_tmp] ASI_M_MMUREGS, %g0)
mov AC_M_SFSR, %glob_tmp
LEON_PI(lda [%glob_tmp] ASI_LEON_MMUREGS, %glob_tmp)
SUN_PI_(lda [%glob_tmp] ASI_M_MMUREGS, %glob_tmp)
andcc %glob_tmp, 0x2, %g0 ! did we fault?
be,a spwin_finish_up + 0x4 ! cool beans, success
restore %g0, %g0, %g0
rd %psr, %glob_tmp
b spwin_user_stack_is_bolixed + 0x4 ! we faulted, ugh
nop
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