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alistair23-linux/arch/metag/kernel/signal.c
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

337 lines
8.5 KiB
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// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (C) 1991,1992 Linus Torvalds
* Copyright (C) 2005-2012 Imagination Technologies Ltd.
*
* 1997-11-28 Modified for POSIX.1b signals by Richard Henderson
*
*/
#include <linux/sched.h>
#include <linux/sched/task_stack.h>
#include <linux/mm.h>
#include <linux/smp.h>
#include <linux/kernel.h>
#include <linux/signal.h>
#include <linux/errno.h>
#include <linux/wait.h>
#include <linux/ptrace.h>
#include <linux/unistd.h>
#include <linux/stddef.h>
#include <linux/personality.h>
#include <linux/uaccess.h>
#include <linux/tracehook.h>
#include <asm/ucontext.h>
#include <asm/cacheflush.h>
#include <asm/switch.h>
#include <asm/syscall.h>
#include <asm/syscalls.h>
#define REG_FLAGS ctx.SaveMask
#define REG_RETVAL ctx.DX[0].U0
#define REG_SYSCALL ctx.DX[0].U1
#define REG_SP ctx.AX[0].U0
#define REG_ARG1 ctx.DX[3].U1
#define REG_ARG2 ctx.DX[3].U0
#define REG_ARG3 ctx.DX[2].U1
#define REG_PC ctx.CurrPC
#define REG_RTP ctx.DX[4].U1
struct rt_sigframe {
struct siginfo info;
struct ucontext uc;
unsigned long retcode[2];
};
static int restore_sigcontext(struct pt_regs *regs,
struct sigcontext __user *sc)
{
int err;
/* Always make any pending restarted system calls return -EINTR */
current->restart_block.fn = do_no_restart_syscall;
err = metag_gp_regs_copyin(regs, 0, sizeof(struct user_gp_regs), NULL,
&sc->regs);
if (!err)
err = metag_cb_regs_copyin(regs, 0,
sizeof(struct user_cb_regs), NULL,
&sc->cb);
if (!err)
err = metag_rp_state_copyin(regs, 0,
sizeof(struct user_rp_state), NULL,
&sc->rp);
/* This is a user-mode context. */
regs->REG_FLAGS |= TBICTX_PRIV_BIT;
return err;
}
long sys_rt_sigreturn(void)
{
/* NOTE - Meta stack goes UPWARDS - so we wind the stack back */
struct pt_regs *regs = current_pt_regs();
struct rt_sigframe __user *frame;
sigset_t set;
frame = (__force struct rt_sigframe __user *)(regs->REG_SP -
sizeof(*frame));
if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
goto badframe;
if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
goto badframe;
set_current_blocked(&set);
if (restore_sigcontext(regs, &frame->uc.uc_mcontext))
goto badframe;
if (restore_altstack(&frame->uc.uc_stack))
goto badframe;
return regs->REG_RETVAL;
badframe:
force_sig(SIGSEGV, current);
return 0;
}
static int setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs,
unsigned long mask)
{
int err;
err = metag_gp_regs_copyout(regs, 0, sizeof(struct user_gp_regs), NULL,
&sc->regs);
if (!err)
err = metag_cb_regs_copyout(regs, 0,
sizeof(struct user_cb_regs), NULL,
&sc->cb);
if (!err)
err = metag_rp_state_copyout(regs, 0,
sizeof(struct user_rp_state), NULL,
&sc->rp);
/* OK, clear that cbuf flag in the old context, or our stored
* catch buffer will be restored when we go to call the signal
* handler. Also clear out the CBRP RA/RD pipe bit incase
* that is pending as well!
* Note that as we have already stored this context, these
* flags will get restored on sigreturn to their original
* state.
*/
regs->REG_FLAGS &= ~(TBICTX_XCBF_BIT | TBICTX_CBUF_BIT |
TBICTX_CBRP_BIT);
/* Clear out the LSM_STEP bits in case we are in the middle of
* and MSET/MGET.
*/
regs->ctx.Flags &= ~TXSTATUS_LSM_STEP_BITS;
err |= __put_user(mask, &sc->oldmask);
return err;
}
/*
* Determine which stack to use..
*/
static void __user *get_sigframe(struct ksignal *ksig, unsigned long sp)
{
sp = sigsp(sp, ksig);
sp = (sp + 7) & ~7; /* 8byte align stack */
return (void __user *)sp;
}
static int setup_rt_frame(struct ksignal *ksig, sigset_t *set,
struct pt_regs *regs)
{
struct rt_sigframe __user *frame;
int err;
unsigned long code;
frame = get_sigframe(ksig, regs->REG_SP);
if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
return -EFAULT;
err = copy_siginfo_to_user(&frame->info, &ksig->info);
/* Create the ucontext. */
err |= __put_user(0, &frame->uc.uc_flags);
err |= __put_user(0, (unsigned long __user *)&frame->uc.uc_link);
err |= __save_altstack(&frame->uc.uc_stack, regs->REG_SP);
err |= setup_sigcontext(&frame->uc.uc_mcontext,
regs, set->sig[0]);
err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
if (err)
return -EFAULT;
/* Set up to return from userspace. */
/* MOV D1Re0 (D1.0), #__NR_rt_sigreturn */
code = 0x03000004 | (__NR_rt_sigreturn << 3);
err |= __put_user(code, (unsigned long __user *)(&frame->retcode[0]));
/* SWITCH #__METAG_SW_SYS */
code = __METAG_SW_ENCODING(SYS);
err |= __put_user(code, (unsigned long __user *)(&frame->retcode[1]));
if (err)
return -EFAULT;
/* Set up registers for signal handler */
regs->REG_RTP = (unsigned long) frame->retcode;
regs->REG_SP = (unsigned long) frame + sizeof(*frame);
regs->REG_ARG1 = ksig->sig;
regs->REG_ARG2 = (unsigned long) &frame->info;
regs->REG_ARG3 = (unsigned long) &frame->uc;
regs->REG_PC = (unsigned long) ksig->ka.sa.sa_handler;
pr_debug("SIG deliver (%s:%d): sp=%p pc=%08x pr=%08x\n",
current->comm, current->pid, frame, regs->REG_PC,
regs->REG_RTP);
/* Now pass size of 'new code' into sigtramp so we can do a more
* effective cache flush - directed rather than 'full flush'.
*/
flush_cache_sigtramp(regs->REG_RTP, sizeof(frame->retcode));
return 0;
}
static void handle_signal(struct ksignal *ksig, struct pt_regs *regs)
{
sigset_t *oldset = sigmask_to_save();
int ret;
/* Set up the stack frame */
ret = setup_rt_frame(ksig, oldset, regs);
signal_setup_done(ret, ksig, test_thread_flag(TIF_SINGLESTEP));
}
/*
* Notes for Meta.
* We have moved from the old 2.4.9 SH way of using syscall_nr (in the stored
* context) to passing in the syscall flag on the stack.
* This is because having syscall_nr in our context does not fit with TBX, and
* corrupted the stack.
*/
static int do_signal(struct pt_regs *regs, int syscall)
{
unsigned int retval = 0, continue_addr = 0, restart_addr = 0;
int restart = 0;
struct ksignal ksig;
/*
* By the end of rt_sigreturn the context describes the point that the
* signal was taken (which may happen to be just before a syscall if
* it's already been restarted). This should *never* be mistaken for a
* system call in need of restarting.
*/
if (syscall == __NR_rt_sigreturn)
syscall = -1;
/* Did we come from a system call? */
if (syscall >= 0) {
continue_addr = regs->REG_PC;
restart_addr = continue_addr - 4;
retval = regs->REG_RETVAL;
/*
* Prepare for system call restart. We do this here so that a
* debugger will see the already changed PC.
*/
switch (retval) {
case -ERESTART_RESTARTBLOCK:
restart = -2;
case -ERESTARTNOHAND:
case -ERESTARTSYS:
case -ERESTARTNOINTR:
++restart;
regs->REG_PC = restart_addr;
break;
}
}
/*
* Get the signal to deliver. When running under ptrace, at this point
* the debugger may change all our registers ...
*/
get_signal(&ksig);
/*
* Depending on the signal settings we may need to revert the decision
* to restart the system call. But skip this if a debugger has chosen to
* restart at a different PC.
*/
if (regs->REG_PC != restart_addr)
restart = 0;
if (ksig.sig > 0) {
if (unlikely(restart)) {
if (retval == -ERESTARTNOHAND
|| retval == -ERESTART_RESTARTBLOCK
|| (retval == -ERESTARTSYS
&& !(ksig.ka.sa.sa_flags & SA_RESTART))) {
regs->REG_RETVAL = -EINTR;
regs->REG_PC = continue_addr;
}
}
/* Whee! Actually deliver the signal. */
handle_signal(&ksig, regs);
return 0;
}
/* Handlerless -ERESTART_RESTARTBLOCK re-enters via restart_syscall */
if (unlikely(restart < 0))
regs->REG_SYSCALL = __NR_restart_syscall;
/*
* If there's no signal to deliver, we just put the saved sigmask back.
*/
restore_saved_sigmask();
return restart;
}
int do_work_pending(struct pt_regs *regs, unsigned int thread_flags,
int syscall)
{
do {
if (likely(thread_flags & _TIF_NEED_RESCHED)) {
schedule();
} else {
if (unlikely(!user_mode(regs)))
return 0;
local_irq_enable();
if (thread_flags & _TIF_SIGPENDING) {
int restart = do_signal(regs, syscall);
if (unlikely(restart)) {
/*
* Restart without handlers.
* Deal with it without leaving
* the kernel space.
*/
return restart;
}
syscall = -1;
} else {
clear_thread_flag(TIF_NOTIFY_RESUME);
tracehook_notify_resume(regs);
}
}
local_irq_disable();
thread_flags = current_thread_info()->flags;
} while (thread_flags & _TIF_WORK_MASK);
return 0;
}
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