WSL2-Linux-Kernel/arch/ia64/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
/*
* Architecture-specific signal handling support.
*
* Copyright (C) 1999-2004 Hewlett-Packard Co
* David Mosberger-Tang <davidm@hpl.hp.com>
*
* Derived from i386 and Alpha versions.
*/
#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/ptrace.h>
#include <linux/tracehook.h>
#include <linux/sched.h>
#include <linux/signal.h>
#include <linux/smp.h>
#include <linux/stddef.h>
#include <linux/tty.h>
#include <linux/binfmts.h>
#include <linux/unistd.h>
#include <linux/wait.h>
#include <asm/intrinsics.h>
#include <linux/uaccess.h>
#include <asm/rse.h>
#include <asm/sigcontext.h>
#include "sigframe.h"
#define DEBUG_SIG 0
#define STACK_ALIGN 16 /* minimal alignment for stack pointer */
#if _NSIG_WORDS > 1
# define PUT_SIGSET(k,u) __copy_to_user((u)->sig, (k)->sig, sizeof(sigset_t))
# define GET_SIGSET(k,u) __copy_from_user((k)->sig, (u)->sig, sizeof(sigset_t))
#else
# define PUT_SIGSET(k,u) __put_user((k)->sig[0], &(u)->sig[0])
# define GET_SIGSET(k,u) __get_user((k)->sig[0], &(u)->sig[0])
#endif
static long
restore_sigcontext (struct sigcontext __user *sc, struct sigscratch *scr)
{
unsigned long ip, flags, nat, um, cfm, rsc;
long err;
/* Always make any pending restarted system calls return -EINTR */
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;
/* restore scratch that always needs gets updated during signal delivery: */
err = __get_user(flags, &sc->sc_flags);
err |= __get_user(nat, &sc->sc_nat);
err |= __get_user(ip, &sc->sc_ip); /* instruction pointer */
err |= __get_user(cfm, &sc->sc_cfm);
err |= __get_user(um, &sc->sc_um); /* user mask */
err |= __get_user(rsc, &sc->sc_ar_rsc);
err |= __get_user(scr->pt.ar_unat, &sc->sc_ar_unat);
err |= __get_user(scr->pt.ar_fpsr, &sc->sc_ar_fpsr);
err |= __get_user(scr->pt.ar_pfs, &sc->sc_ar_pfs);
err |= __get_user(scr->pt.pr, &sc->sc_pr); /* predicates */
err |= __get_user(scr->pt.b0, &sc->sc_br[0]); /* b0 (rp) */
err |= __get_user(scr->pt.b6, &sc->sc_br[6]); /* b6 */
err |= __copy_from_user(&scr->pt.r1, &sc->sc_gr[1], 8); /* r1 */
err |= __copy_from_user(&scr->pt.r8, &sc->sc_gr[8], 4*8); /* r8-r11 */
err |= __copy_from_user(&scr->pt.r12, &sc->sc_gr[12], 2*8); /* r12-r13 */
err |= __copy_from_user(&scr->pt.r15, &sc->sc_gr[15], 8); /* r15 */
scr->pt.cr_ifs = cfm | (1UL << 63);
scr->pt.ar_rsc = rsc | (3 << 2); /* force PL3 */
/* establish new instruction pointer: */
scr->pt.cr_iip = ip & ~0x3UL;
ia64_psr(&scr->pt)->ri = ip & 0x3;
scr->pt.cr_ipsr = (scr->pt.cr_ipsr & ~IA64_PSR_UM) | (um & IA64_PSR_UM);
scr->scratch_unat = ia64_put_scratch_nat_bits(&scr->pt, nat);
if (!(flags & IA64_SC_FLAG_IN_SYSCALL)) {
/* Restore most scratch-state only when not in syscall. */
err |= __get_user(scr->pt.ar_ccv, &sc->sc_ar_ccv); /* ar.ccv */
err |= __get_user(scr->pt.b7, &sc->sc_br[7]); /* b7 */
err |= __get_user(scr->pt.r14, &sc->sc_gr[14]); /* r14 */
err |= __copy_from_user(&scr->pt.ar_csd, &sc->sc_ar25, 2*8); /* ar.csd & ar.ssd */
err |= __copy_from_user(&scr->pt.r2, &sc->sc_gr[2], 2*8); /* r2-r3 */
err |= __copy_from_user(&scr->pt.r16, &sc->sc_gr[16], 16*8); /* r16-r31 */
}
if ((flags & IA64_SC_FLAG_FPH_VALID) != 0) {
struct ia64_psr *psr = ia64_psr(&scr->pt);
err |= __copy_from_user(current->thread.fph, &sc->sc_fr[32], 96*16);
psr->mfh = 0; /* drop signal handler's fph contents... */
preempt_disable();
if (psr->dfh)
ia64_drop_fpu(current);
else {
/* We already own the local fph, otherwise psr->dfh wouldn't be 0. */
__ia64_load_fpu(current->thread.fph);
ia64_set_local_fpu_owner(current);
}
preempt_enable();
}
return err;
}
long
ia64_rt_sigreturn (struct sigscratch *scr)
{
extern char ia64_strace_leave_kernel, ia64_leave_kernel;
struct sigcontext __user *sc;
sigset_t set;
long retval;
sc = &((struct sigframe __user *) (scr->pt.r12 + 16))->sc;
/*
* When we return to the previously executing context, r8 and r10 have already
* been setup the way we want them. Indeed, if the signal wasn't delivered while
* in a system call, we must not touch r8 or r10 as otherwise user-level state
* could be corrupted.
*/
retval = (long) &ia64_leave_kernel;
if (test_thread_flag(TIF_SYSCALL_TRACE)
|| test_thread_flag(TIF_SYSCALL_AUDIT))
/*
* strace expects to be notified after sigreturn returns even though the
* context to which we return may not be in the middle of a syscall.
* Thus, the return-value that strace displays for sigreturn is
* meaningless.
*/
retval = (long) &ia64_strace_leave_kernel;
Remove 'type' argument from access_ok() function Nobody has actually used the type (VERIFY_READ vs VERIFY_WRITE) argument of the user address range verification function since we got rid of the old racy i386-only code to walk page tables by hand. It existed because the original 80386 would not honor the write protect bit when in kernel mode, so you had to do COW by hand before doing any user access. But we haven't supported that in a long time, and these days the 'type' argument is a purely historical artifact. A discussion about extending 'user_access_begin()' to do the range checking resulted this patch, because there is no way we're going to move the old VERIFY_xyz interface to that model. And it's best done at the end of the merge window when I've done most of my merges, so let's just get this done once and for all. This patch was mostly done with a sed-script, with manual fix-ups for the cases that weren't of the trivial 'access_ok(VERIFY_xyz' form. There were a couple of notable cases: - csky still had the old "verify_area()" name as an alias. - the iter_iov code had magical hardcoded knowledge of the actual values of VERIFY_{READ,WRITE} (not that they mattered, since nothing really used it) - microblaze used the type argument for a debug printout but other than those oddities this should be a total no-op patch. I tried to fix up all architectures, did fairly extensive grepping for access_ok() uses, and the changes are trivial, but I may have missed something. Any missed conversion should be trivially fixable, though. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-01-04 05:57:57 +03:00
if (!access_ok(sc, sizeof(*sc)))
goto give_sigsegv;
if (GET_SIGSET(&set, &sc->sc_mask))
goto give_sigsegv;
set_current_blocked(&set);
if (restore_sigcontext(sc, scr))
goto give_sigsegv;
#if DEBUG_SIG
printk("SIG return (%s:%d): sp=%lx ip=%lx\n",
current->comm, current->pid, scr->pt.r12, scr->pt.cr_iip);
#endif
if (restore_altstack(&sc->sc_stack))
goto give_sigsegv;
return retval;
give_sigsegv:
force_sig(SIGSEGV, current);
return retval;
}
/*
* This does just the minimum required setup of sigcontext.
* Specifically, it only installs data that is either not knowable at
* the user-level or that gets modified before execution in the
* trampoline starts. Everything else is done at the user-level.
*/
static long
setup_sigcontext (struct sigcontext __user *sc, sigset_t *mask, struct sigscratch *scr)
{
unsigned long flags = 0, ifs, cfm, nat;
long err = 0;
ifs = scr->pt.cr_ifs;
if (on_sig_stack((unsigned long) sc))
flags |= IA64_SC_FLAG_ONSTACK;
if ((ifs & (1UL << 63)) == 0)
/* if cr_ifs doesn't have the valid bit set, we got here through a syscall */
flags |= IA64_SC_FLAG_IN_SYSCALL;
cfm = ifs & ((1UL << 38) - 1);
ia64_flush_fph(current);
if ((current->thread.flags & IA64_THREAD_FPH_VALID)) {
flags |= IA64_SC_FLAG_FPH_VALID;
err = __copy_to_user(&sc->sc_fr[32], current->thread.fph, 96*16);
}
nat = ia64_get_scratch_nat_bits(&scr->pt, scr->scratch_unat);
err |= __put_user(flags, &sc->sc_flags);
err |= __put_user(nat, &sc->sc_nat);
err |= PUT_SIGSET(mask, &sc->sc_mask);
err |= __put_user(cfm, &sc->sc_cfm);
err |= __put_user(scr->pt.cr_ipsr & IA64_PSR_UM, &sc->sc_um);
err |= __put_user(scr->pt.ar_rsc, &sc->sc_ar_rsc);
err |= __put_user(scr->pt.ar_unat, &sc->sc_ar_unat); /* ar.unat */
err |= __put_user(scr->pt.ar_fpsr, &sc->sc_ar_fpsr); /* ar.fpsr */
err |= __put_user(scr->pt.ar_pfs, &sc->sc_ar_pfs);
err |= __put_user(scr->pt.pr, &sc->sc_pr); /* predicates */
err |= __put_user(scr->pt.b0, &sc->sc_br[0]); /* b0 (rp) */
err |= __put_user(scr->pt.b6, &sc->sc_br[6]); /* b6 */
err |= __copy_to_user(&sc->sc_gr[1], &scr->pt.r1, 8); /* r1 */
err |= __copy_to_user(&sc->sc_gr[8], &scr->pt.r8, 4*8); /* r8-r11 */
err |= __copy_to_user(&sc->sc_gr[12], &scr->pt.r12, 2*8); /* r12-r13 */
err |= __copy_to_user(&sc->sc_gr[15], &scr->pt.r15, 8); /* r15 */
err |= __put_user(scr->pt.cr_iip + ia64_psr(&scr->pt)->ri, &sc->sc_ip);
if (!(flags & IA64_SC_FLAG_IN_SYSCALL)) {
/* Copy scratch regs to sigcontext if the signal didn't interrupt a syscall. */
err |= __put_user(scr->pt.ar_ccv, &sc->sc_ar_ccv); /* ar.ccv */
err |= __put_user(scr->pt.b7, &sc->sc_br[7]); /* b7 */
err |= __put_user(scr->pt.r14, &sc->sc_gr[14]); /* r14 */
err |= __copy_to_user(&sc->sc_ar25, &scr->pt.ar_csd, 2*8); /* ar.csd & ar.ssd */
err |= __copy_to_user(&sc->sc_gr[2], &scr->pt.r2, 2*8); /* r2-r3 */
err |= __copy_to_user(&sc->sc_gr[16], &scr->pt.r16, 16*8); /* r16-r31 */
}
return err;
}
/*
* Check whether the register-backing store is already on the signal stack.
*/
static inline int
rbs_on_sig_stack (unsigned long bsp)
{
return (bsp - current->sas_ss_sp < current->sas_ss_size);
}
static long
setup_frame(struct ksignal *ksig, sigset_t *set, struct sigscratch *scr)
{
extern char __kernel_sigtramp[];
unsigned long tramp_addr, new_rbs = 0, new_sp;
struct sigframe __user *frame;
long err;
new_sp = scr->pt.r12;
tramp_addr = (unsigned long) __kernel_sigtramp;
if (ksig->ka.sa.sa_flags & SA_ONSTACK) {
int onstack = sas_ss_flags(new_sp);
if (onstack == 0) {
new_sp = current->sas_ss_sp + current->sas_ss_size;
/*
* We need to check for the register stack being on the
* signal stack separately, because it's switched
* separately (memory stack is switched in the kernel,
* register stack is switched in the signal trampoline).
*/
if (!rbs_on_sig_stack(scr->pt.ar_bspstore))
new_rbs = ALIGN(current->sas_ss_sp,
sizeof(long));
} else if (onstack == SS_ONSTACK) {
unsigned long check_sp;
/*
* If we are on the alternate signal stack and would
* overflow it, don't. Return an always-bogus address
* instead so we will die with SIGSEGV.
*/
check_sp = (new_sp - sizeof(*frame)) & -STACK_ALIGN;
if (!likely(on_sig_stack(check_sp))) {
force_sigsegv(ksig->sig, current);
return 1;
}
}
}
frame = (void __user *) ((new_sp - sizeof(*frame)) & -STACK_ALIGN);
Remove 'type' argument from access_ok() function Nobody has actually used the type (VERIFY_READ vs VERIFY_WRITE) argument of the user address range verification function since we got rid of the old racy i386-only code to walk page tables by hand. It existed because the original 80386 would not honor the write protect bit when in kernel mode, so you had to do COW by hand before doing any user access. But we haven't supported that in a long time, and these days the 'type' argument is a purely historical artifact. A discussion about extending 'user_access_begin()' to do the range checking resulted this patch, because there is no way we're going to move the old VERIFY_xyz interface to that model. And it's best done at the end of the merge window when I've done most of my merges, so let's just get this done once and for all. This patch was mostly done with a sed-script, with manual fix-ups for the cases that weren't of the trivial 'access_ok(VERIFY_xyz' form. There were a couple of notable cases: - csky still had the old "verify_area()" name as an alias. - the iter_iov code had magical hardcoded knowledge of the actual values of VERIFY_{READ,WRITE} (not that they mattered, since nothing really used it) - microblaze used the type argument for a debug printout but other than those oddities this should be a total no-op patch. I tried to fix up all architectures, did fairly extensive grepping for access_ok() uses, and the changes are trivial, but I may have missed something. Any missed conversion should be trivially fixable, though. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-01-04 05:57:57 +03:00
if (!access_ok(frame, sizeof(*frame))) {
force_sigsegv(ksig->sig, current);
return 1;
}
err = __put_user(ksig->sig, &frame->arg0);
err |= __put_user(&frame->info, &frame->arg1);
err |= __put_user(&frame->sc, &frame->arg2);
err |= __put_user(new_rbs, &frame->sc.sc_rbs_base);
err |= __put_user(0, &frame->sc.sc_loadrs); /* initialize to zero */
err |= __put_user(ksig->ka.sa.sa_handler, &frame->handler);
err |= copy_siginfo_to_user(&frame->info, &ksig->info);
err |= __save_altstack(&frame->sc.sc_stack, scr->pt.r12);
err |= setup_sigcontext(&frame->sc, set, scr);
if (unlikely(err)) {
force_sigsegv(ksig->sig, current);
return 1;
}
scr->pt.r12 = (unsigned long) frame - 16; /* new stack pointer */
scr->pt.ar_fpsr = FPSR_DEFAULT; /* reset fpsr for signal handler */
scr->pt.cr_iip = tramp_addr;
ia64_psr(&scr->pt)->ri = 0; /* start executing in first slot */
ia64_psr(&scr->pt)->be = 0; /* force little-endian byte-order */
/*
* Force the interruption function mask to zero. This has no effect when a
* system-call got interrupted by a signal (since, in that case, scr->pt_cr_ifs is
* ignored), but it has the desirable effect of making it possible to deliver a
* signal with an incomplete register frame (which happens when a mandatory RSE
* load faults). Furthermore, it has no negative effect on the getting the user's
* dirty partition preserved, because that's governed by scr->pt.loadrs.
*/
scr->pt.cr_ifs = (1UL << 63);
/*
* Note: this affects only the NaT bits of the scratch regs (the ones saved in
* pt_regs), which is exactly what we want.
*/
scr->scratch_unat = 0; /* ensure NaT bits of r12 is clear */
#if DEBUG_SIG
printk("SIG deliver (%s:%d): sig=%d sp=%lx ip=%lx handler=%p\n",
current->comm, current->pid, ksig->sig, scr->pt.r12, frame->sc.sc_ip, frame->handler);
#endif
return 0;
}
static long
handle_signal (struct ksignal *ksig, struct sigscratch *scr)
{
int ret = setup_frame(ksig, sigmask_to_save(), scr);
if (!ret)
signal_setup_done(ret, ksig, test_thread_flag(TIF_SINGLESTEP));
return ret;
}
/*
* 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.
*/
void
ia64_do_signal (struct sigscratch *scr, long in_syscall)
{
long restart = in_syscall;
long errno = scr->pt.r8;
struct ksignal ksig;
/*
* This only loops in the rare cases of handle_signal() failing, in which case we
* need to push through a forced SIGSEGV.
*/
while (1) {
get_signal(&ksig);
/*
* get_signal() may have run a debugger (via notify_parent())
* and the debugger may have modified the state (e.g., to arrange for an
* inferior call), thus it's important to check for restarting _after_
* get_signal().
*/
if ((long) scr->pt.r10 != -1)
/*
* A system calls has to be restarted only if one of the error codes
* ERESTARTNOHAND, ERESTARTSYS, or ERESTARTNOINTR is returned. If r10
* isn't -1 then r8 doesn't hold an error code and we don't need to
* restart the syscall, so we can clear the "restart" flag here.
*/
restart = 0;
if (ksig.sig <= 0)
break;
if (unlikely(restart)) {
switch (errno) {
case ERESTART_RESTARTBLOCK:
case ERESTARTNOHAND:
scr->pt.r8 = EINTR;
/* note: scr->pt.r10 is already -1 */
break;
case ERESTARTSYS:
if ((ksig.ka.sa.sa_flags & SA_RESTART) == 0) {
scr->pt.r8 = EINTR;
/* note: scr->pt.r10 is already -1 */
break;
}
case ERESTARTNOINTR:
ia64_decrement_ip(&scr->pt);
restart = 0; /* don't restart twice if handle_signal() fails... */
}
}
/*
* Whee! Actually deliver the signal. If the delivery failed, we need to
* continue to iterate in this loop so we can deliver the SIGSEGV...
*/
if (handle_signal(&ksig, scr))
return;
}
/* Did we come from a system call? */
if (restart) {
/* Restart the system call - no handlers present */
if (errno == ERESTARTNOHAND || errno == ERESTARTSYS || errno == ERESTARTNOINTR
|| errno == ERESTART_RESTARTBLOCK)
{
/*
* Note: the syscall number is in r15 which is saved in
* pt_regs so all we need to do here is adjust ip so that
* the "break" instruction gets re-executed.
*/
ia64_decrement_ip(&scr->pt);
if (errno == ERESTART_RESTARTBLOCK)
scr->pt.r15 = __NR_restart_syscall;
}
}
/* if there's no signal to deliver, we just put the saved sigmask
* back */
restore_saved_sigmask();
}