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linux-stable/arch/sh/kernel/signal_32.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

510 lines
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// SPDX-License-Identifier: GPL-2.0
/*
* linux/arch/sh/kernel/signal.c
*
* Copyright (C) 1991, 1992 Linus Torvalds
*
* 1997-11-28 Modified for POSIX.1b signals by Richard Henderson
*
* SuperH version: Copyright (C) 1999, 2000 Niibe Yutaka & Kaz Kojima
*
*/
#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/tty.h>
#include <linux/elf.h>
#include <linux/personality.h>
#include <linux/binfmts.h>
#include <linux/io.h>
#include <linux/tracehook.h>
#include <asm/ucontext.h>
#include <linux/uaccess.h>
#include <asm/pgtable.h>
#include <asm/cacheflush.h>
#include <asm/syscalls.h>
#include <asm/fpu.h>
struct fdpic_func_descriptor {
unsigned long text;
unsigned long GOT;
};
/*
* The following define adds a 64 byte gap between the signal
* stack frame and previous contents of the stack. This allows
* frame unwinding in a function epilogue but only if a frame
* pointer is used in the function. This is necessary because
* current gcc compilers (<4.3) do not generate unwind info on
* SH for function epilogues.
*/
#define UNWINDGUARD 64
/*
* Do a signal return; undo the signal stack.
*/
#define MOVW(n) (0x9300|((n)-2)) /* Move mem word at PC+n to R3 */
#if defined(CONFIG_CPU_SH2)
#define TRAP_NOARG 0xc320 /* Syscall w/no args (NR in R3) */
#else
#define TRAP_NOARG 0xc310 /* Syscall w/no args (NR in R3) */
#endif
#define OR_R0_R0 0x200b /* or r0,r0 (insert to avoid hardware bug) */
struct sigframe
{
struct sigcontext sc;
unsigned long extramask[_NSIG_WORDS-1];
u16 retcode[8];
};
struct rt_sigframe
{
struct siginfo info;
struct ucontext uc;
u16 retcode[8];
};
#ifdef CONFIG_SH_FPU
static inline int restore_sigcontext_fpu(struct sigcontext __user *sc)
{
struct task_struct *tsk = current;
if (!(boot_cpu_data.flags & CPU_HAS_FPU))
return 0;
set_used_math();
return __copy_from_user(&tsk->thread.xstate->hardfpu, &sc->sc_fpregs[0],
sizeof(long)*(16*2+2));
}
static inline int save_sigcontext_fpu(struct sigcontext __user *sc,
struct pt_regs *regs)
{
struct task_struct *tsk = current;
if (!(boot_cpu_data.flags & CPU_HAS_FPU))
return 0;
if (!used_math())
return __put_user(0, &sc->sc_ownedfp);
if (__put_user(1, &sc->sc_ownedfp))
return -EFAULT;
/* This will cause a "finit" to be triggered by the next
attempted FPU operation by the 'current' process.
*/
clear_used_math();
unlazy_fpu(tsk, regs);
return __copy_to_user(&sc->sc_fpregs[0], &tsk->thread.xstate->hardfpu,
sizeof(long)*(16*2+2));
}
#endif /* CONFIG_SH_FPU */
static int
restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc, int *r0_p)
{
unsigned int err = 0;
#define COPY(x) err |= __get_user(regs->x, &sc->sc_##x)
COPY(regs[1]);
COPY(regs[2]); COPY(regs[3]);
COPY(regs[4]); COPY(regs[5]);
COPY(regs[6]); COPY(regs[7]);
COPY(regs[8]); COPY(regs[9]);
COPY(regs[10]); COPY(regs[11]);
COPY(regs[12]); COPY(regs[13]);
COPY(regs[14]); COPY(regs[15]);
COPY(gbr); COPY(mach);
COPY(macl); COPY(pr);
COPY(sr); COPY(pc);
#undef COPY
#ifdef CONFIG_SH_FPU
if (boot_cpu_data.flags & CPU_HAS_FPU) {
int owned_fp;
struct task_struct *tsk = current;
regs->sr |= SR_FD; /* Release FPU */
clear_fpu(tsk, regs);
clear_used_math();
err |= __get_user (owned_fp, &sc->sc_ownedfp);
if (owned_fp)
err |= restore_sigcontext_fpu(sc);
}
#endif
regs->tra = -1; /* disable syscall checks */
err |= __get_user(*r0_p, &sc->sc_regs[0]);
return err;
}
asmlinkage int sys_sigreturn(void)
{
struct pt_regs *regs = current_pt_regs();
struct sigframe __user *frame = (struct sigframe __user *)regs->regs[15];
sigset_t set;
int r0;
/* Always make any pending restarted system calls return -EINTR */
current->restart_block.fn = do_no_restart_syscall;
if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
goto badframe;
if (__get_user(set.sig[0], &frame->sc.oldmask)
|| (_NSIG_WORDS > 1
&& __copy_from_user(&set.sig[1], &frame->extramask,
sizeof(frame->extramask))))
goto badframe;
set_current_blocked(&set);
if (restore_sigcontext(regs, &frame->sc, &r0))
goto badframe;
return r0;
badframe:
force_sig(SIGSEGV, current);
return 0;
}
asmlinkage int sys_rt_sigreturn(void)
{
struct pt_regs *regs = current_pt_regs();
struct rt_sigframe __user *frame = (struct rt_sigframe __user *)regs->regs[15];
sigset_t set;
int r0;
/* Always make any pending restarted system calls return -EINTR */
current->restart_block.fn = do_no_restart_syscall;
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, &r0))
goto badframe;
if (restore_altstack(&frame->uc.uc_stack))
goto badframe;
return r0;
badframe:
force_sig(SIGSEGV, current);
return 0;
}
/*
* Set up a signal frame.
*/
static int
setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs,
unsigned long mask)
{
int err = 0;
#define COPY(x) err |= __put_user(regs->x, &sc->sc_##x)
COPY(regs[0]); COPY(regs[1]);
COPY(regs[2]); COPY(regs[3]);
COPY(regs[4]); COPY(regs[5]);
COPY(regs[6]); COPY(regs[7]);
COPY(regs[8]); COPY(regs[9]);
COPY(regs[10]); COPY(regs[11]);
COPY(regs[12]); COPY(regs[13]);
COPY(regs[14]); COPY(regs[15]);
COPY(gbr); COPY(mach);
COPY(macl); COPY(pr);
COPY(sr); COPY(pc);
#undef COPY
#ifdef CONFIG_SH_FPU
err |= save_sigcontext_fpu(sc, regs);
#endif
/* non-iBCS2 extensions.. */
err |= __put_user(mask, &sc->oldmask);
return err;
}
/*
* Determine which stack to use..
*/
static inline void __user *
get_sigframe(struct k_sigaction *ka, unsigned long sp, size_t frame_size)
{
if (ka->sa.sa_flags & SA_ONSTACK) {
if (sas_ss_flags(sp) == 0)
sp = current->sas_ss_sp + current->sas_ss_size;
}
return (void __user *)((sp - (frame_size+UNWINDGUARD)) & -8ul);
}
/* These symbols are defined with the addresses in the vsyscall page.
See vsyscall-trapa.S. */
extern void __kernel_sigreturn(void);
extern void __kernel_rt_sigreturn(void);
static int setup_frame(struct ksignal *ksig, sigset_t *set,
struct pt_regs *regs)
{
struct sigframe __user *frame;
int err = 0, sig = ksig->sig;
frame = get_sigframe(&ksig->ka, regs->regs[15], sizeof(*frame));
if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
return -EFAULT;
err |= setup_sigcontext(&frame->sc, regs, set->sig[0]);
if (_NSIG_WORDS > 1)
err |= __copy_to_user(frame->extramask, &set->sig[1],
sizeof(frame->extramask));
/* Set up to return from userspace. If provided, use a stub
already in userspace. */
if (ksig->ka.sa.sa_flags & SA_RESTORER) {
regs->pr = (unsigned long) ksig->ka.sa.sa_restorer;
#ifdef CONFIG_VSYSCALL
} else if (likely(current->mm->context.vdso)) {
regs->pr = VDSO_SYM(&__kernel_sigreturn);
#endif
} else {
/* Generate return code (system call to sigreturn) */
err |= __put_user(MOVW(7), &frame->retcode[0]);
err |= __put_user(TRAP_NOARG, &frame->retcode[1]);
err |= __put_user(OR_R0_R0, &frame->retcode[2]);
err |= __put_user(OR_R0_R0, &frame->retcode[3]);
err |= __put_user(OR_R0_R0, &frame->retcode[4]);
err |= __put_user(OR_R0_R0, &frame->retcode[5]);
err |= __put_user(OR_R0_R0, &frame->retcode[6]);
err |= __put_user((__NR_sigreturn), &frame->retcode[7]);
regs->pr = (unsigned long) frame->retcode;
flush_icache_range(regs->pr, regs->pr + sizeof(frame->retcode));
}
if (err)
return -EFAULT;
/* Set up registers for signal handler */
regs->regs[15] = (unsigned long) frame;
regs->regs[4] = sig; /* Arg for signal handler */
regs->regs[5] = 0;
regs->regs[6] = (unsigned long) &frame->sc;
if (current->personality & FDPIC_FUNCPTRS) {
struct fdpic_func_descriptor __user *funcptr =
(struct fdpic_func_descriptor __user *)ksig->ka.sa.sa_handler;
err |= __get_user(regs->pc, &funcptr->text);
err |= __get_user(regs->regs[12], &funcptr->GOT);
} else
regs->pc = (unsigned long)ksig->ka.sa.sa_handler;
if (err)
return -EFAULT;
pr_debug("SIG deliver (%s:%d): sp=%p pc=%08lx pr=%08lx\n",
current->comm, task_pid_nr(current), frame, regs->pc, regs->pr);
return 0;
}
static int setup_rt_frame(struct ksignal *ksig, sigset_t *set,
struct pt_regs *regs)
{
struct rt_sigframe __user *frame;
int err = 0, sig = ksig->sig;
frame = get_sigframe(&ksig->ka, regs->regs[15], sizeof(*frame));
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(NULL, &frame->uc.uc_link);
err |= __save_altstack(&frame->uc.uc_stack, regs->regs[15]);
err |= setup_sigcontext(&frame->uc.uc_mcontext,
regs, set->sig[0]);
err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
/* Set up to return from userspace. If provided, use a stub
already in userspace. */
if (ksig->ka.sa.sa_flags & SA_RESTORER) {
regs->pr = (unsigned long) ksig->ka.sa.sa_restorer;
#ifdef CONFIG_VSYSCALL
} else if (likely(current->mm->context.vdso)) {
regs->pr = VDSO_SYM(&__kernel_rt_sigreturn);
#endif
} else {
/* Generate return code (system call to rt_sigreturn) */
err |= __put_user(MOVW(7), &frame->retcode[0]);
err |= __put_user(TRAP_NOARG, &frame->retcode[1]);
err |= __put_user(OR_R0_R0, &frame->retcode[2]);
err |= __put_user(OR_R0_R0, &frame->retcode[3]);
err |= __put_user(OR_R0_R0, &frame->retcode[4]);
err |= __put_user(OR_R0_R0, &frame->retcode[5]);
err |= __put_user(OR_R0_R0, &frame->retcode[6]);
err |= __put_user((__NR_rt_sigreturn), &frame->retcode[7]);
regs->pr = (unsigned long) frame->retcode;
flush_icache_range(regs->pr, regs->pr + sizeof(frame->retcode));
}
if (err)
return -EFAULT;
/* Set up registers for signal handler */
regs->regs[15] = (unsigned long) frame;
regs->regs[4] = sig; /* Arg for signal handler */
regs->regs[5] = (unsigned long) &frame->info;
regs->regs[6] = (unsigned long) &frame->uc;
if (current->personality & FDPIC_FUNCPTRS) {
struct fdpic_func_descriptor __user *funcptr =
(struct fdpic_func_descriptor __user *)ksig->ka.sa.sa_handler;
err |= __get_user(regs->pc, &funcptr->text);
err |= __get_user(regs->regs[12], &funcptr->GOT);
} else
regs->pc = (unsigned long)ksig->ka.sa.sa_handler;
if (err)
return -EFAULT;
pr_debug("SIG deliver (%s:%d): sp=%p pc=%08lx pr=%08lx\n",
current->comm, task_pid_nr(current), frame, regs->pc, regs->pr);
return 0;
}
static inline void
handle_syscall_restart(unsigned long save_r0, struct pt_regs *regs,
struct sigaction *sa)
{
/* If we're not from a syscall, bail out */
if (regs->tra < 0)
return;
/* check for system call restart.. */
switch (regs->regs[0]) {
case -ERESTART_RESTARTBLOCK:
case -ERESTARTNOHAND:
no_system_call_restart:
regs->regs[0] = -EINTR;
break;
case -ERESTARTSYS:
if (!(sa->sa_flags & SA_RESTART))
goto no_system_call_restart;
/* fallthrough */
case -ERESTARTNOINTR:
regs->regs[0] = save_r0;
regs->pc -= instruction_size(__raw_readw(regs->pc - 4));
break;
}
}
/*
* OK, we're invoking a handler
*/
static void
handle_signal(struct ksignal *ksig, struct pt_regs *regs, unsigned int save_r0)
{
sigset_t *oldset = sigmask_to_save();
int ret;
/* Set up the stack frame */
if (ksig->ka.sa.sa_flags & SA_SIGINFO)
ret = setup_rt_frame(ksig, oldset, regs);
else
ret = setup_frame(ksig, oldset, regs);
signal_setup_done(ret, ksig, test_thread_flag(TIF_SINGLESTEP));
}
/*
* Note that 'init' is a special process: it doesn't get signals it doesn't
* want to handle. Thus you cannot kill init even with a SIGKILL even by
* mistake.
*
* Note that we go through the signals twice: once to check the signals that
* the kernel can handle, and then we build all the user-level signal handling
* stack-frames in one go after that.
*/
static void do_signal(struct pt_regs *regs, unsigned int save_r0)
{
struct ksignal ksig;
/*
* We want the common case to go fast, which
* is why we may in certain cases get here from
* kernel mode. Just return without doing anything
* if so.
*/
if (!user_mode(regs))
return;
if (get_signal(&ksig)) {
handle_syscall_restart(save_r0, regs, &ksig.ka.sa);
/* Whee! Actually deliver the signal. */
handle_signal(&ksig, regs, save_r0);
return;
}
/* Did we come from a system call? */
if (regs->tra >= 0) {
/* Restart the system call - no handlers present */
if (regs->regs[0] == -ERESTARTNOHAND ||
regs->regs[0] == -ERESTARTSYS ||
regs->regs[0] == -ERESTARTNOINTR) {
regs->regs[0] = save_r0;
regs->pc -= instruction_size(__raw_readw(regs->pc - 4));
} else if (regs->regs[0] == -ERESTART_RESTARTBLOCK) {
regs->pc -= instruction_size(__raw_readw(regs->pc - 4));
regs->regs[3] = __NR_restart_syscall;
}
}
/*
* If there's no signal to deliver, we just put the saved sigmask
* back.
*/
restore_saved_sigmask();
}
asmlinkage void do_notify_resume(struct pt_regs *regs, unsigned int save_r0,
unsigned long thread_info_flags)
{
/* deal with pending signal delivery */
if (thread_info_flags & _TIF_SIGPENDING)
do_signal(regs, save_r0);
if (thread_info_flags & _TIF_NOTIFY_RESUME) {
clear_thread_flag(TIF_NOTIFY_RESUME);
tracehook_notify_resume(regs);
}
}
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