WSL2-Linux-Kernel/arch/alpha/kernel/signal.c

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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>
2017-11-01 17:07:57 +03:00
// SPDX-License-Identifier: GPL-2.0
/*
* linux/arch/alpha/kernel/signal.c
*
* Copyright (C) 1995 Linus Torvalds
*
* 1997-11-02 Modified for POSIX.1b signals by Richard Henderson
*/
#include <linux/sched/signal.h>
#include <linux/sched/task_stack.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/mm.h>
#include <linux/smp.h>
#include <linux/stddef.h>
#include <linux/tty.h>
#include <linux/binfmts.h>
#include <linux/bitops.h>
#include <linux/syscalls.h>
#include <linux/tracehook.h>
#include <linux/uaccess.h>
#include <asm/sigcontext.h>
#include <asm/ucontext.h>
#include "proto.h"
#define DEBUG_SIG 0
#define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
asmlinkage void ret_from_sys_call(void);
/*
* The OSF/1 sigprocmask calling sequence is different from the
* C sigprocmask() sequence..
*/
SYSCALL_DEFINE2(osf_sigprocmask, int, how, unsigned long, newmask)
{
sigset_t oldmask;
sigset_t mask;
unsigned long res;
siginitset(&mask, newmask & _BLOCKABLE);
res = sigprocmask(how, &mask, &oldmask);
if (!res) {
force_successful_syscall_return();
res = oldmask.sig[0];
}
return res;
}
SYSCALL_DEFINE3(osf_sigaction, int, sig,
const struct osf_sigaction __user *, act,
struct osf_sigaction __user *, oact)
{
struct k_sigaction new_ka, old_ka;
int ret;
if (act) {
old_sigset_t mask;
if (!access_ok(VERIFY_READ, act, sizeof(*act)) ||
__get_user(new_ka.sa.sa_handler, &act->sa_handler) ||
__get_user(new_ka.sa.sa_flags, &act->sa_flags) ||
__get_user(mask, &act->sa_mask))
return -EFAULT;
siginitset(&new_ka.sa.sa_mask, mask);
new_ka.ka_restorer = NULL;
}
ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL);
if (!ret && oact) {
if (!access_ok(VERIFY_WRITE, oact, sizeof(*oact)) ||
__put_user(old_ka.sa.sa_handler, &oact->sa_handler) ||
__put_user(old_ka.sa.sa_flags, &oact->sa_flags) ||
__put_user(old_ka.sa.sa_mask.sig[0], &oact->sa_mask))
return -EFAULT;
}
return ret;
}
SYSCALL_DEFINE5(rt_sigaction, int, sig, const struct sigaction __user *, act,
struct sigaction __user *, oact,
size_t, sigsetsize, void __user *, restorer)
{
struct k_sigaction new_ka, old_ka;
int ret;
/* XXX: Don't preclude handling different sized sigset_t's. */
if (sigsetsize != sizeof(sigset_t))
return -EINVAL;
if (act) {
new_ka.ka_restorer = restorer;
if (copy_from_user(&new_ka.sa, act, sizeof(*act)))
return -EFAULT;
}
ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL);
if (!ret && oact) {
if (copy_to_user(oact, &old_ka.sa, sizeof(*oact)))
return -EFAULT;
}
return ret;
}
/*
* Do a signal return; undo the signal stack.
*/
#if _NSIG_WORDS > 1
# error "Non SA_SIGINFO frame needs rearranging"
#endif
struct sigframe
{
struct sigcontext sc;
unsigned int retcode[3];
};
struct rt_sigframe
{
struct siginfo info;
struct ucontext uc;
unsigned int retcode[3];
};
/* If this changes, userland unwinders that Know Things about our signal
frame will break. Do not undertake lightly. It also implies an ABI
change wrt the size of siginfo_t, which may cause some pain. */
extern char compile_time_assert
[offsetof(struct rt_sigframe, uc.uc_mcontext) == 176 ? 1 : -1];
#define INSN_MOV_R30_R16 0x47fe0410
#define INSN_LDI_R0 0x201f0000
#define INSN_CALLSYS 0x00000083
static long
restore_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs)
{
unsigned long usp;
struct switch_stack *sw = (struct switch_stack *)regs - 1;
long i, err = __get_user(regs->pc, &sc->sc_pc);
all arches, signal: move restart_block to struct task_struct If an attacker can cause a controlled kernel stack overflow, overwriting the restart block is a very juicy exploit target. This is because the restart_block is held in the same memory allocation as the kernel stack. Moving the restart block to struct task_struct prevents this exploit by making the restart_block harder to locate. Note that there are other fields in thread_info that are also easy targets, at least on some architectures. It's also a decent simplification, since the restart code is more or less identical on all architectures. [james.hogan@imgtec.com: metag: align thread_info::supervisor_stack] Signed-off-by: Andy Lutomirski <luto@amacapital.net> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Kees Cook <keescook@chromium.org> Cc: David Miller <davem@davemloft.net> Acked-by: Richard Weinberger <richard@nod.at> Cc: Richard Henderson <rth@twiddle.net> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: Matt Turner <mattst88@gmail.com> Cc: Vineet Gupta <vgupta@synopsys.com> Cc: Russell King <rmk@arm.linux.org.uk> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Haavard Skinnemoen <hskinnemoen@gmail.com> Cc: Hans-Christian Egtvedt <egtvedt@samfundet.no> Cc: Steven Miao <realmz6@gmail.com> Cc: Mark Salter <msalter@redhat.com> Cc: Aurelien Jacquiot <a-jacquiot@ti.com> Cc: Mikael Starvik <starvik@axis.com> Cc: Jesper Nilsson <jesper.nilsson@axis.com> Cc: David Howells <dhowells@redhat.com> Cc: Richard Kuo <rkuo@codeaurora.org> Cc: "Luck, Tony" <tony.luck@intel.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Michal Simek <monstr@monstr.eu> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Jonas Bonn <jonas@southpole.se> Cc: "James E.J. Bottomley" <jejb@parisc-linux.org> Cc: Helge Deller <deller@gmx.de> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc) Tested-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc) Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Chen Liqin <liqin.linux@gmail.com> Cc: Lennox Wu <lennox.wu@gmail.com> Cc: Chris Metcalf <cmetcalf@ezchip.com> Cc: Guan Xuetao <gxt@mprc.pku.edu.cn> Cc: Chris Zankel <chris@zankel.net> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Guenter Roeck <linux@roeck-us.net> Signed-off-by: James Hogan <james.hogan@imgtec.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-13 02:01:14 +03:00
current->restart_block.fn = do_no_restart_syscall;
sw->r26 = (unsigned long) ret_from_sys_call;
err |= __get_user(regs->r0, sc->sc_regs+0);
err |= __get_user(regs->r1, sc->sc_regs+1);
err |= __get_user(regs->r2, sc->sc_regs+2);
err |= __get_user(regs->r3, sc->sc_regs+3);
err |= __get_user(regs->r4, sc->sc_regs+4);
err |= __get_user(regs->r5, sc->sc_regs+5);
err |= __get_user(regs->r6, sc->sc_regs+6);
err |= __get_user(regs->r7, sc->sc_regs+7);
err |= __get_user(regs->r8, sc->sc_regs+8);
err |= __get_user(sw->r9, sc->sc_regs+9);
err |= __get_user(sw->r10, sc->sc_regs+10);
err |= __get_user(sw->r11, sc->sc_regs+11);
err |= __get_user(sw->r12, sc->sc_regs+12);
err |= __get_user(sw->r13, sc->sc_regs+13);
err |= __get_user(sw->r14, sc->sc_regs+14);
err |= __get_user(sw->r15, sc->sc_regs+15);
err |= __get_user(regs->r16, sc->sc_regs+16);
err |= __get_user(regs->r17, sc->sc_regs+17);
err |= __get_user(regs->r18, sc->sc_regs+18);
err |= __get_user(regs->r19, sc->sc_regs+19);
err |= __get_user(regs->r20, sc->sc_regs+20);
err |= __get_user(regs->r21, sc->sc_regs+21);
err |= __get_user(regs->r22, sc->sc_regs+22);
err |= __get_user(regs->r23, sc->sc_regs+23);
err |= __get_user(regs->r24, sc->sc_regs+24);
err |= __get_user(regs->r25, sc->sc_regs+25);
err |= __get_user(regs->r26, sc->sc_regs+26);
err |= __get_user(regs->r27, sc->sc_regs+27);
err |= __get_user(regs->r28, sc->sc_regs+28);
err |= __get_user(regs->gp, sc->sc_regs+29);
err |= __get_user(usp, sc->sc_regs+30);
wrusp(usp);
for (i = 0; i < 31; i++)
err |= __get_user(sw->fp[i], sc->sc_fpregs+i);
err |= __get_user(sw->fp[31], &sc->sc_fpcr);
return err;
}
/* Note that this syscall is also used by setcontext(3) to install
a given sigcontext. This because it's impossible to set *all*
registers and transfer control from userland. */
asmlinkage void
do_sigreturn(struct sigcontext __user *sc)
{
struct pt_regs *regs = current_pt_regs();
sigset_t set;
/* Verify that it's a good sigcontext before using it */
if (!access_ok(VERIFY_READ, sc, sizeof(*sc)))
goto give_sigsegv;
if (__get_user(set.sig[0], &sc->sc_mask))
goto give_sigsegv;
set_current_blocked(&set);
if (restore_sigcontext(sc, regs))
goto give_sigsegv;
/* Send SIGTRAP if we're single-stepping: */
if (ptrace_cancel_bpt (current)) {
send_sig_fault(SIGTRAP, TRAP_BRKPT, (void __user *) regs->pc, 0,
current);
}
return;
give_sigsegv:
force_sig(SIGSEGV, current);
}
asmlinkage void
do_rt_sigreturn(struct rt_sigframe __user *frame)
{
struct pt_regs *regs = current_pt_regs();
sigset_t set;
/* Verify that it's a good ucontext_t before using it */
if (!access_ok(VERIFY_READ, &frame->uc, sizeof(frame->uc)))
goto give_sigsegv;
if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
goto give_sigsegv;
set_current_blocked(&set);
if (restore_sigcontext(&frame->uc.uc_mcontext, regs))
goto give_sigsegv;
/* Send SIGTRAP if we're single-stepping: */
if (ptrace_cancel_bpt (current)) {
send_sig_fault(SIGTRAP, TRAP_BRKPT, (void __user *) regs->pc, 0,
current);
}
return;
give_sigsegv:
force_sig(SIGSEGV, current);
}
/*
* Set up a signal frame.
*/
static inline void __user *
get_sigframe(struct ksignal *ksig, unsigned long sp, size_t frame_size)
{
return (void __user *)((sigsp(sp, ksig) - frame_size) & -32ul);
}
static long
setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs,
unsigned long mask, unsigned long sp)
{
struct switch_stack *sw = (struct switch_stack *)regs - 1;
long i, err = 0;
err |= __put_user(on_sig_stack((unsigned long)sc), &sc->sc_onstack);
err |= __put_user(mask, &sc->sc_mask);
err |= __put_user(regs->pc, &sc->sc_pc);
err |= __put_user(8, &sc->sc_ps);
err |= __put_user(regs->r0 , sc->sc_regs+0);
err |= __put_user(regs->r1 , sc->sc_regs+1);
err |= __put_user(regs->r2 , sc->sc_regs+2);
err |= __put_user(regs->r3 , sc->sc_regs+3);
err |= __put_user(regs->r4 , sc->sc_regs+4);
err |= __put_user(regs->r5 , sc->sc_regs+5);
err |= __put_user(regs->r6 , sc->sc_regs+6);
err |= __put_user(regs->r7 , sc->sc_regs+7);
err |= __put_user(regs->r8 , sc->sc_regs+8);
err |= __put_user(sw->r9 , sc->sc_regs+9);
err |= __put_user(sw->r10 , sc->sc_regs+10);
err |= __put_user(sw->r11 , sc->sc_regs+11);
err |= __put_user(sw->r12 , sc->sc_regs+12);
err |= __put_user(sw->r13 , sc->sc_regs+13);
err |= __put_user(sw->r14 , sc->sc_regs+14);
err |= __put_user(sw->r15 , sc->sc_regs+15);
err |= __put_user(regs->r16, sc->sc_regs+16);
err |= __put_user(regs->r17, sc->sc_regs+17);
err |= __put_user(regs->r18, sc->sc_regs+18);
err |= __put_user(regs->r19, sc->sc_regs+19);
err |= __put_user(regs->r20, sc->sc_regs+20);
err |= __put_user(regs->r21, sc->sc_regs+21);
err |= __put_user(regs->r22, sc->sc_regs+22);
err |= __put_user(regs->r23, sc->sc_regs+23);
err |= __put_user(regs->r24, sc->sc_regs+24);
err |= __put_user(regs->r25, sc->sc_regs+25);
err |= __put_user(regs->r26, sc->sc_regs+26);
err |= __put_user(regs->r27, sc->sc_regs+27);
err |= __put_user(regs->r28, sc->sc_regs+28);
err |= __put_user(regs->gp , sc->sc_regs+29);
err |= __put_user(sp, sc->sc_regs+30);
err |= __put_user(0, sc->sc_regs+31);
for (i = 0; i < 31; i++)
err |= __put_user(sw->fp[i], sc->sc_fpregs+i);
err |= __put_user(0, sc->sc_fpregs+31);
err |= __put_user(sw->fp[31], &sc->sc_fpcr);
err |= __put_user(regs->trap_a0, &sc->sc_traparg_a0);
err |= __put_user(regs->trap_a1, &sc->sc_traparg_a1);
err |= __put_user(regs->trap_a2, &sc->sc_traparg_a2);
return err;
}
static int
setup_frame(struct ksignal *ksig, sigset_t *set, struct pt_regs *regs)
{
unsigned long oldsp, r26, err = 0;
struct sigframe __user *frame;
oldsp = rdusp();
frame = get_sigframe(ksig, oldsp, sizeof(*frame));
if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
return -EFAULT;
err |= setup_sigcontext(&frame->sc, regs, set->sig[0], oldsp);
if (err)
return -EFAULT;
/* Set up to return from userspace. If provided, use a stub
already in userspace. */
r26 = (unsigned long) ksig->ka.ka_restorer;
if (!r26) {
err |= __put_user(INSN_MOV_R30_R16, frame->retcode+0);
err |= __put_user(INSN_LDI_R0+__NR_sigreturn, frame->retcode+1);
err |= __put_user(INSN_CALLSYS, frame->retcode+2);
imb();
r26 = (unsigned long) frame->retcode;
}
/* Check that everything was written properly. */
if (err)
return err;
/* "Return" to the handler */
regs->r26 = r26;
regs->r27 = regs->pc = (unsigned long) ksig->ka.sa.sa_handler;
regs->r16 = ksig->sig; /* a0: signal number */
regs->r17 = 0; /* a1: exception code */
regs->r18 = (unsigned long) &frame->sc; /* a2: sigcontext pointer */
wrusp((unsigned long) frame);
#if DEBUG_SIG
printk("SIG deliver (%s:%d): sp=%p pc=%p ra=%p\n",
current->comm, current->pid, frame, regs->pc, regs->r26);
#endif
return 0;
}
static int
setup_rt_frame(struct ksignal *ksig, sigset_t *set, struct pt_regs *regs)
{
unsigned long oldsp, r26, err = 0;
struct rt_sigframe __user *frame;
oldsp = rdusp();
frame = get_sigframe(ksig, oldsp, 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(0, &frame->uc.uc_link);
err |= __put_user(set->sig[0], &frame->uc.uc_osf_sigmask);
err |= __save_altstack(&frame->uc.uc_stack, oldsp);
err |= setup_sigcontext(&frame->uc.uc_mcontext, regs,
set->sig[0], oldsp);
err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
if (err)
return -EFAULT;
/* Set up to return from userspace. If provided, use a stub
already in userspace. */
r26 = (unsigned long) ksig->ka.ka_restorer;
if (!r26) {
err |= __put_user(INSN_MOV_R30_R16, frame->retcode+0);
err |= __put_user(INSN_LDI_R0+__NR_rt_sigreturn,
frame->retcode+1);
err |= __put_user(INSN_CALLSYS, frame->retcode+2);
imb();
r26 = (unsigned long) frame->retcode;
}
if (err)
return -EFAULT;
/* "Return" to the handler */
regs->r26 = r26;
regs->r27 = regs->pc = (unsigned long) ksig->ka.sa.sa_handler;
regs->r16 = ksig->sig; /* a0: signal number */
regs->r17 = (unsigned long) &frame->info; /* a1: siginfo pointer */
regs->r18 = (unsigned long) &frame->uc; /* a2: ucontext pointer */
wrusp((unsigned long) frame);
#if DEBUG_SIG
printk("SIG deliver (%s:%d): sp=%p pc=%p ra=%p\n",
current->comm, current->pid, frame, regs->pc, regs->r26);
#endif
return 0;
}
/*
* OK, we're invoking a handler.
*/
static inline void
handle_signal(struct ksignal *ksig, struct pt_regs *regs)
{
sigset_t *oldset = sigmask_to_save();
int ret;
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, 0);
}
static inline void
syscall_restart(unsigned long r0, unsigned long r19,
struct pt_regs *regs, struct k_sigaction *ka)
{
switch (regs->r0) {
case ERESTARTSYS:
if (!(ka->sa.sa_flags & SA_RESTART)) {
case ERESTARTNOHAND:
regs->r0 = EINTR;
break;
}
/* fallthrough */
case ERESTARTNOINTR:
regs->r0 = r0; /* reset v0 and a3 and replay syscall */
regs->r19 = r19;
regs->pc -= 4;
break;
case ERESTART_RESTARTBLOCK:
regs->r0 = EINTR;
break;
}
}
/*
* 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.
*
* "r0" and "r19" are the registers we need to restore for system call
* restart. "r0" is also used as an indicator whether we can restart at
* all (if we get here from anything but a syscall return, it will be 0)
*/
static void
do_signal(struct pt_regs *regs, unsigned long r0, unsigned long r19)
{
unsigned long single_stepping = ptrace_cancel_bpt(current);
struct ksignal ksig;
/* This lets the debugger run, ... */
if (get_signal(&ksig)) {
/* ... so re-check the single stepping. */
single_stepping |= ptrace_cancel_bpt(current);
/* Whee! Actually deliver the signal. */
if (r0)
syscall_restart(r0, r19, regs, &ksig.ka);
handle_signal(&ksig, regs);
} else {
single_stepping |= ptrace_cancel_bpt(current);
if (r0) {
switch (regs->r0) {
case ERESTARTNOHAND:
case ERESTARTSYS:
case ERESTARTNOINTR:
/* Reset v0 and a3 and replay syscall. */
regs->r0 = r0;
regs->r19 = r19;
regs->pc -= 4;
break;
case ERESTART_RESTARTBLOCK:
/* Set v0 to the restart_syscall and replay */
regs->r0 = __NR_restart_syscall;
regs->pc -= 4;
break;
}
}
restore_saved_sigmask();
}
if (single_stepping)
ptrace_set_bpt(current); /* re-set breakpoint */
}
void
do_work_pending(struct pt_regs *regs, unsigned long thread_flags,
unsigned long r0, unsigned long r19)
{
do {
if (thread_flags & _TIF_NEED_RESCHED) {
schedule();
} else {
local_irq_enable();
if (thread_flags & _TIF_SIGPENDING) {
do_signal(regs, r0, r19);
r0 = 0;
} 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);
}