linux_dsm_epyc7002/arch/sparc/kernel/signal_64.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 21:07:57 +07:00
// SPDX-License-Identifier: GPL-2.0
/*
* arch/sparc64/kernel/signal.c
*
* Copyright (C) 1991, 1992 Linus Torvalds
* Copyright (C) 1995, 2008 David S. Miller (davem@davemloft.net)
* Copyright (C) 1996 Miguel de Icaza (miguel@nuclecu.unam.mx)
* Copyright (C) 1997 Eddie C. Dost (ecd@skynet.be)
* Copyright (C) 1997,1998 Jakub Jelinek (jj@sunsite.mff.cuni.cz)
*/
#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/signal.h>
#include <linux/errno.h>
#include <linux/wait.h>
#include <linux/ptrace.h>
#include <linux/tracehook.h>
#include <linux/unistd.h>
#include <linux/mm.h>
#include <linux/tty.h>
#include <linux/binfmts.h>
#include <linux/bitops.h>
#include <linux/context_tracking.h>
#include <linux/uaccess.h>
#include <asm/ptrace.h>
#include <asm/pgtable.h>
#include <asm/fpumacro.h>
#include <asm/uctx.h>
#include <asm/siginfo.h>
#include <asm/visasm.h>
#include <asm/switch_to.h>
#include <asm/cacheflush.h>
#include "sigutil.h"
#include "systbls.h"
#include "kernel.h"
#include "entry.h"
/* {set, get}context() needed for 64-bit SparcLinux userland. */
asmlinkage void sparc64_set_context(struct pt_regs *regs)
{
struct ucontext __user *ucp = (struct ucontext __user *)
regs->u_regs[UREG_I0];
enum ctx_state prev_state = exception_enter();
mc_gregset_t __user *grp;
unsigned long pc, npc, tstate;
unsigned long fp, i7;
unsigned char fenab;
int err;
synchronize_user_stack();
if (get_thread_wsaved() ||
(((unsigned long)ucp) & (sizeof(unsigned long)-1)) ||
(!__access_ok(ucp, sizeof(*ucp))))
goto do_sigsegv;
grp = &ucp->uc_mcontext.mc_gregs;
err = __get_user(pc, &((*grp)[MC_PC]));
err |= __get_user(npc, &((*grp)[MC_NPC]));
if (err || ((pc | npc) & 3))
goto do_sigsegv;
if (regs->u_regs[UREG_I1]) {
sigset_t set;
if (_NSIG_WORDS == 1) {
if (__get_user(set.sig[0], &ucp->uc_sigmask.sig[0]))
goto do_sigsegv;
} else {
if (__copy_from_user(&set, &ucp->uc_sigmask, sizeof(sigset_t)))
goto do_sigsegv;
}
set_current_blocked(&set);
}
if (test_thread_flag(TIF_32BIT)) {
pc &= 0xffffffff;
npc &= 0xffffffff;
}
regs->tpc = pc;
regs->tnpc = npc;
err |= __get_user(regs->y, &((*grp)[MC_Y]));
err |= __get_user(tstate, &((*grp)[MC_TSTATE]));
regs->tstate &= ~(TSTATE_ASI | TSTATE_ICC | TSTATE_XCC);
regs->tstate |= (tstate & (TSTATE_ASI | TSTATE_ICC | TSTATE_XCC));
err |= __get_user(regs->u_regs[UREG_G1], (&(*grp)[MC_G1]));
err |= __get_user(regs->u_regs[UREG_G2], (&(*grp)[MC_G2]));
err |= __get_user(regs->u_regs[UREG_G3], (&(*grp)[MC_G3]));
err |= __get_user(regs->u_regs[UREG_G4], (&(*grp)[MC_G4]));
err |= __get_user(regs->u_regs[UREG_G5], (&(*grp)[MC_G5]));
err |= __get_user(regs->u_regs[UREG_G6], (&(*grp)[MC_G6]));
/* Skip %g7 as that's the thread register in userspace. */
err |= __get_user(regs->u_regs[UREG_I0], (&(*grp)[MC_O0]));
err |= __get_user(regs->u_regs[UREG_I1], (&(*grp)[MC_O1]));
err |= __get_user(regs->u_regs[UREG_I2], (&(*grp)[MC_O2]));
err |= __get_user(regs->u_regs[UREG_I3], (&(*grp)[MC_O3]));
err |= __get_user(regs->u_regs[UREG_I4], (&(*grp)[MC_O4]));
err |= __get_user(regs->u_regs[UREG_I5], (&(*grp)[MC_O5]));
err |= __get_user(regs->u_regs[UREG_I6], (&(*grp)[MC_O6]));
err |= __get_user(regs->u_regs[UREG_I7], (&(*grp)[MC_O7]));
err |= __get_user(fp, &(ucp->uc_mcontext.mc_fp));
err |= __get_user(i7, &(ucp->uc_mcontext.mc_i7));
err |= __put_user(fp,
(&(((struct reg_window __user *)(STACK_BIAS+regs->u_regs[UREG_I6]))->ins[6])));
err |= __put_user(i7,
(&(((struct reg_window __user *)(STACK_BIAS+regs->u_regs[UREG_I6]))->ins[7])));
err |= __get_user(fenab, &(ucp->uc_mcontext.mc_fpregs.mcfpu_enab));
if (fenab) {
unsigned long *fpregs = current_thread_info()->fpregs;
unsigned long fprs;
fprs_write(0);
err |= __get_user(fprs, &(ucp->uc_mcontext.mc_fpregs.mcfpu_fprs));
if (fprs & FPRS_DL)
err |= copy_from_user(fpregs,
&(ucp->uc_mcontext.mc_fpregs.mcfpu_fregs),
(sizeof(unsigned int) * 32));
if (fprs & FPRS_DU)
err |= copy_from_user(fpregs+16,
((unsigned long __user *)&(ucp->uc_mcontext.mc_fpregs.mcfpu_fregs))+16,
(sizeof(unsigned int) * 32));
err |= __get_user(current_thread_info()->xfsr[0],
&(ucp->uc_mcontext.mc_fpregs.mcfpu_fsr));
err |= __get_user(current_thread_info()->gsr[0],
&(ucp->uc_mcontext.mc_fpregs.mcfpu_gsr));
regs->tstate &= ~TSTATE_PEF;
}
if (err)
goto do_sigsegv;
out:
exception_exit(prev_state);
return;
do_sigsegv:
force_sig(SIGSEGV, current);
goto out;
}
asmlinkage void sparc64_get_context(struct pt_regs *regs)
{
struct ucontext __user *ucp = (struct ucontext __user *)
regs->u_regs[UREG_I0];
enum ctx_state prev_state = exception_enter();
mc_gregset_t __user *grp;
mcontext_t __user *mcp;
unsigned long fp, i7;
unsigned char fenab;
int err;
synchronize_user_stack();
if (get_thread_wsaved() || clear_user(ucp, sizeof(*ucp)))
goto do_sigsegv;
#if 1
fenab = 0; /* IMO get_context is like any other system call, thus modifies FPU state -jj */
#else
fenab = (current_thread_info()->fpsaved[0] & FPRS_FEF);
#endif
mcp = &ucp->uc_mcontext;
grp = &mcp->mc_gregs;
/* Skip over the trap instruction, first. */
if (test_thread_flag(TIF_32BIT)) {
regs->tpc = (regs->tnpc & 0xffffffff);
regs->tnpc = (regs->tnpc + 4) & 0xffffffff;
} else {
regs->tpc = regs->tnpc;
regs->tnpc += 4;
}
err = 0;
if (_NSIG_WORDS == 1)
err |= __put_user(current->blocked.sig[0],
(unsigned long __user *)&ucp->uc_sigmask);
else
err |= __copy_to_user(&ucp->uc_sigmask, &current->blocked,
sizeof(sigset_t));
err |= __put_user(regs->tstate, &((*grp)[MC_TSTATE]));
err |= __put_user(regs->tpc, &((*grp)[MC_PC]));
err |= __put_user(regs->tnpc, &((*grp)[MC_NPC]));
err |= __put_user(regs->y, &((*grp)[MC_Y]));
err |= __put_user(regs->u_regs[UREG_G1], &((*grp)[MC_G1]));
err |= __put_user(regs->u_regs[UREG_G2], &((*grp)[MC_G2]));
err |= __put_user(regs->u_regs[UREG_G3], &((*grp)[MC_G3]));
err |= __put_user(regs->u_regs[UREG_G4], &((*grp)[MC_G4]));
err |= __put_user(regs->u_regs[UREG_G5], &((*grp)[MC_G5]));
err |= __put_user(regs->u_regs[UREG_G6], &((*grp)[MC_G6]));
err |= __put_user(regs->u_regs[UREG_G7], &((*grp)[MC_G7]));
err |= __put_user(regs->u_regs[UREG_I0], &((*grp)[MC_O0]));
err |= __put_user(regs->u_regs[UREG_I1], &((*grp)[MC_O1]));
err |= __put_user(regs->u_regs[UREG_I2], &((*grp)[MC_O2]));
err |= __put_user(regs->u_regs[UREG_I3], &((*grp)[MC_O3]));
err |= __put_user(regs->u_regs[UREG_I4], &((*grp)[MC_O4]));
err |= __put_user(regs->u_regs[UREG_I5], &((*grp)[MC_O5]));
err |= __put_user(regs->u_regs[UREG_I6], &((*grp)[MC_O6]));
err |= __put_user(regs->u_regs[UREG_I7], &((*grp)[MC_O7]));
err |= __get_user(fp,
(&(((struct reg_window __user *)(STACK_BIAS+regs->u_regs[UREG_I6]))->ins[6])));
err |= __get_user(i7,
(&(((struct reg_window __user *)(STACK_BIAS+regs->u_regs[UREG_I6]))->ins[7])));
err |= __put_user(fp, &(mcp->mc_fp));
err |= __put_user(i7, &(mcp->mc_i7));
err |= __put_user(fenab, &(mcp->mc_fpregs.mcfpu_enab));
if (fenab) {
unsigned long *fpregs = current_thread_info()->fpregs;
unsigned long fprs;
fprs = current_thread_info()->fpsaved[0];
if (fprs & FPRS_DL)
err |= copy_to_user(&(mcp->mc_fpregs.mcfpu_fregs), fpregs,
(sizeof(unsigned int) * 32));
if (fprs & FPRS_DU)
err |= copy_to_user(
((unsigned long __user *)&(mcp->mc_fpregs.mcfpu_fregs))+16, fpregs+16,
(sizeof(unsigned int) * 32));
err |= __put_user(current_thread_info()->xfsr[0], &(mcp->mc_fpregs.mcfpu_fsr));
err |= __put_user(current_thread_info()->gsr[0], &(mcp->mc_fpregs.mcfpu_gsr));
err |= __put_user(fprs, &(mcp->mc_fpregs.mcfpu_fprs));
}
if (err)
goto do_sigsegv;
out:
exception_exit(prev_state);
return;
do_sigsegv:
force_sig(SIGSEGV, current);
goto out;
}
/* Checks if the fp is valid. We always build rt signal frames which
* are 16-byte aligned, therefore we can always enforce that the
* restore frame has that property as well.
*/
static bool invalid_frame_pointer(void __user *fp)
{
if (((unsigned long) fp) & 15)
return true;
return false;
}
struct rt_signal_frame {
struct sparc_stackf ss;
siginfo_t info;
struct pt_regs regs;
__siginfo_fpu_t __user *fpu_save;
stack_t stack;
sigset_t mask;
__siginfo_rwin_t *rwin_save;
};
void do_rt_sigreturn(struct pt_regs *regs)
{
unsigned long tpc, tnpc, tstate, ufp;
struct rt_signal_frame __user *sf;
__siginfo_fpu_t __user *fpu_save;
__siginfo_rwin_t __user *rwin_save;
sigset_t set;
int 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 06:01:14 +07:00
current->restart_block.fn = do_no_restart_syscall;
synchronize_user_stack ();
sf = (struct rt_signal_frame __user *)
(regs->u_regs [UREG_FP] + STACK_BIAS);
/* 1. Make sure we are not getting garbage from the user */
if (invalid_frame_pointer(sf))
goto segv;
if (get_user(ufp, &sf->regs.u_regs[UREG_FP]))
goto segv;
if ((ufp + STACK_BIAS) & 0x7)
goto segv;
err = __get_user(tpc, &sf->regs.tpc);
err |= __get_user(tnpc, &sf->regs.tnpc);
if (test_thread_flag(TIF_32BIT)) {
tpc &= 0xffffffff;
tnpc &= 0xffffffff;
}
err |= ((tpc | tnpc) & 3);
/* 2. Restore the state */
err |= __get_user(regs->y, &sf->regs.y);
err |= __get_user(tstate, &sf->regs.tstate);
err |= copy_from_user(regs->u_regs, sf->regs.u_regs, sizeof(regs->u_regs));
/* User can only change condition codes and %asi in %tstate. */
regs->tstate &= ~(TSTATE_ASI | TSTATE_ICC | TSTATE_XCC);
regs->tstate |= (tstate & (TSTATE_ASI | TSTATE_ICC | TSTATE_XCC));
err |= __get_user(fpu_save, &sf->fpu_save);
if (!err && fpu_save)
err |= restore_fpu_state(regs, fpu_save);
err |= __copy_from_user(&set, &sf->mask, sizeof(sigset_t));
err |= restore_altstack(&sf->stack);
if (err)
goto segv;
err |= __get_user(rwin_save, &sf->rwin_save);
if (!err && rwin_save) {
if (restore_rwin_state(rwin_save))
goto segv;
}
regs->tpc = tpc;
regs->tnpc = tnpc;
/* Prevent syscall restart. */
sparc: Fix debugger syscall restart interactions. So, forever, we've had this ptrace_signal_deliver implementation which tries to handle all of the nasties that can occur when the debugger looks at a process about to take a signal. It's meant to address all of these issues inside of the kernel so that the debugger need not be mindful of such things. Problem is, this doesn't work. The idea was that we should do the syscall restart business first, so that the debugger captures that state. Otherwise, if the debugger for example saves the child's state, makes the child execute something else, then restores the saved state, we won't handle the syscall restart properly because we lose the "we're in a syscall" state. The code here worked for most cases, but if the debugger actually passes the signal through to the child unaltered, it's possible that we would do a syscall restart when we shouldn't have. In particular this breaks the case of debugging a process under a gdb which is being debugged by yet another gdb. gdb uses sigsuspend to wait for SIGCHLD of the inferior, but if gdb itself is being debugged by a top-level gdb we get a ptrace_stop(). The top-level gdb does a PTRACE_CONT with SIGCHLD to let the inferior gdb see the signal. But ptrace_signal_deliver() assumed the debugger would cancel out the signal and therefore did a syscall restart, because the return error was ERESTARTNOHAND. Fix this by simply making ptrace_signal_deliver() a nop, and providing a way for the debugger to control system call restarting properly: 1) Report a "in syscall" software bit in regs->{tstate,psr}. It is set early on in trap entry to a system call and is fully visible to the debugger via ptrace() and regsets. 2) Test this bit right before doing a syscall restart. We have to do a final recheck right after get_signal_to_deliver() in case the debugger cleared the bit during ptrace_stop(). 3) Clear the bit in trap return so we don't accidently try to set that bit in the real register. As a result we also get a ptrace_{is,clear}_syscall() for sparc32 just like sparc64 has. M68K has this same exact bug, and is now the only other user of the ptrace_signal_deliver hook. It needs to be fixed in the same exact way as sparc. Signed-off-by: David S. Miller <davem@davemloft.net>
2008-05-11 16:07:19 +07:00
pt_regs_clear_syscall(regs);
set_current_blocked(&set);
return;
segv:
force_sig(SIGSEGV, current);
}
static inline void __user *get_sigframe(struct ksignal *ksig, struct pt_regs *regs, unsigned long framesize)
{
unsigned long sp = regs->u_regs[UREG_FP] + STACK_BIAS;
/*
* 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.
*/
if (on_sig_stack(sp) && !likely(on_sig_stack(sp - framesize)))
return (void __user *) -1L;
/* This is the X/Open sanctioned signal stack switching. */
sp = sigsp(sp, ksig) - framesize;
/* Always align the stack frame. This handles two cases. First,
* sigaltstack need not be mindful of platform specific stack
* alignment. Second, if we took this signal because the stack
* is not aligned properly, we'd like to take the signal cleanly
* and report that.
*/
sp &= ~15UL;
return (void __user *) sp;
}
static inline int
setup_rt_frame(struct ksignal *ksig, struct pt_regs *regs)
{
struct rt_signal_frame __user *sf;
int wsaved, err, sf_size;
void __user *tail;
/* 1. Make sure everything is clean */
synchronize_user_stack();
save_and_clear_fpu();
wsaved = get_thread_wsaved();
sf_size = sizeof(struct rt_signal_frame);
if (current_thread_info()->fpsaved[0] & FPRS_FEF)
sf_size += sizeof(__siginfo_fpu_t);
if (wsaved)
sf_size += sizeof(__siginfo_rwin_t);
sf = (struct rt_signal_frame __user *)
get_sigframe(ksig, regs, sf_size);
if (invalid_frame_pointer (sf)) {
do_exit(SIGILL); /* won't return, actually */
return -EINVAL;
}
tail = (sf + 1);
/* 2. Save the current process state */
err = copy_to_user(&sf->regs, regs, sizeof (*regs));
if (current_thread_info()->fpsaved[0] & FPRS_FEF) {
__siginfo_fpu_t __user *fpu_save = tail;
tail += sizeof(__siginfo_fpu_t);
err |= save_fpu_state(regs, fpu_save);
err |= __put_user((u64)fpu_save, &sf->fpu_save);
} else {
err |= __put_user(0, &sf->fpu_save);
}
if (wsaved) {
__siginfo_rwin_t __user *rwin_save = tail;
tail += sizeof(__siginfo_rwin_t);
err |= save_rwin_state(wsaved, rwin_save);
err |= __put_user((u64)rwin_save, &sf->rwin_save);
set_thread_wsaved(0);
} else {
err |= __put_user(0, &sf->rwin_save);
}
/* Setup sigaltstack */
err |= __save_altstack(&sf->stack, regs->u_regs[UREG_FP]);
err |= copy_to_user(&sf->mask, sigmask_to_save(), sizeof(sigset_t));
if (!wsaved) {
err |= copy_in_user((u64 __user *)sf,
(u64 __user *)(regs->u_regs[UREG_FP] +
STACK_BIAS),
sizeof(struct reg_window));
} else {
struct reg_window *rp;
rp = &current_thread_info()->reg_window[wsaved - 1];
err |= copy_to_user(sf, rp, sizeof(struct reg_window));
}
if (ksig->ka.sa.sa_flags & SA_SIGINFO)
err |= copy_siginfo_to_user(&sf->info, &ksig->info);
else {
err |= __put_user(ksig->sig, &sf->info.si_signo);
err |= __put_user(SI_NOINFO, &sf->info.si_code);
}
if (err)
return err;
/* 3. signal handler back-trampoline and parameters */
regs->u_regs[UREG_FP] = ((unsigned long) sf) - STACK_BIAS;
regs->u_regs[UREG_I0] = ksig->sig;
regs->u_regs[UREG_I1] = (unsigned long) &sf->info;
/* The sigcontext is passed in this way because of how it
* is defined in GLIBC's /usr/include/bits/sigcontext.h
* for sparc64. It includes the 128 bytes of siginfo_t.
*/
regs->u_regs[UREG_I2] = (unsigned long) &sf->info;
/* 5. signal handler */
regs->tpc = (unsigned long) ksig->ka.sa.sa_handler;
regs->tnpc = (regs->tpc + 4);
if (test_thread_flag(TIF_32BIT)) {
regs->tpc &= 0xffffffff;
regs->tnpc &= 0xffffffff;
}
/* 4. return to kernel instructions */
regs->u_regs[UREG_I7] = (unsigned long)ksig->ka.ka_restorer;
return 0;
}
static inline void syscall_restart(unsigned long orig_i0, struct pt_regs *regs,
sparc: Fix debugger syscall restart interactions. So, forever, we've had this ptrace_signal_deliver implementation which tries to handle all of the nasties that can occur when the debugger looks at a process about to take a signal. It's meant to address all of these issues inside of the kernel so that the debugger need not be mindful of such things. Problem is, this doesn't work. The idea was that we should do the syscall restart business first, so that the debugger captures that state. Otherwise, if the debugger for example saves the child's state, makes the child execute something else, then restores the saved state, we won't handle the syscall restart properly because we lose the "we're in a syscall" state. The code here worked for most cases, but if the debugger actually passes the signal through to the child unaltered, it's possible that we would do a syscall restart when we shouldn't have. In particular this breaks the case of debugging a process under a gdb which is being debugged by yet another gdb. gdb uses sigsuspend to wait for SIGCHLD of the inferior, but if gdb itself is being debugged by a top-level gdb we get a ptrace_stop(). The top-level gdb does a PTRACE_CONT with SIGCHLD to let the inferior gdb see the signal. But ptrace_signal_deliver() assumed the debugger would cancel out the signal and therefore did a syscall restart, because the return error was ERESTARTNOHAND. Fix this by simply making ptrace_signal_deliver() a nop, and providing a way for the debugger to control system call restarting properly: 1) Report a "in syscall" software bit in regs->{tstate,psr}. It is set early on in trap entry to a system call and is fully visible to the debugger via ptrace() and regsets. 2) Test this bit right before doing a syscall restart. We have to do a final recheck right after get_signal_to_deliver() in case the debugger cleared the bit during ptrace_stop(). 3) Clear the bit in trap return so we don't accidently try to set that bit in the real register. As a result we also get a ptrace_{is,clear}_syscall() for sparc32 just like sparc64 has. M68K has this same exact bug, and is now the only other user of the ptrace_signal_deliver hook. It needs to be fixed in the same exact way as sparc. Signed-off-by: David S. Miller <davem@davemloft.net>
2008-05-11 16:07:19 +07:00
struct sigaction *sa)
{
switch (regs->u_regs[UREG_I0]) {
case ERESTART_RESTARTBLOCK:
case ERESTARTNOHAND:
no_system_call_restart:
regs->u_regs[UREG_I0] = EINTR;
regs->tstate |= (TSTATE_ICARRY|TSTATE_XCARRY);
break;
case ERESTARTSYS:
if (!(sa->sa_flags & SA_RESTART))
goto no_system_call_restart;
/* fallthrough */
case ERESTARTNOINTR:
regs->u_regs[UREG_I0] = orig_i0;
regs->tpc -= 4;
regs->tnpc -= 4;
}
}
/* 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.
*/
static void do_signal(struct pt_regs *regs, unsigned long orig_i0)
{
struct ksignal ksig;
sparc: Fix debugger syscall restart interactions. So, forever, we've had this ptrace_signal_deliver implementation which tries to handle all of the nasties that can occur when the debugger looks at a process about to take a signal. It's meant to address all of these issues inside of the kernel so that the debugger need not be mindful of such things. Problem is, this doesn't work. The idea was that we should do the syscall restart business first, so that the debugger captures that state. Otherwise, if the debugger for example saves the child's state, makes the child execute something else, then restores the saved state, we won't handle the syscall restart properly because we lose the "we're in a syscall" state. The code here worked for most cases, but if the debugger actually passes the signal through to the child unaltered, it's possible that we would do a syscall restart when we shouldn't have. In particular this breaks the case of debugging a process under a gdb which is being debugged by yet another gdb. gdb uses sigsuspend to wait for SIGCHLD of the inferior, but if gdb itself is being debugged by a top-level gdb we get a ptrace_stop(). The top-level gdb does a PTRACE_CONT with SIGCHLD to let the inferior gdb see the signal. But ptrace_signal_deliver() assumed the debugger would cancel out the signal and therefore did a syscall restart, because the return error was ERESTARTNOHAND. Fix this by simply making ptrace_signal_deliver() a nop, and providing a way for the debugger to control system call restarting properly: 1) Report a "in syscall" software bit in regs->{tstate,psr}. It is set early on in trap entry to a system call and is fully visible to the debugger via ptrace() and regsets. 2) Test this bit right before doing a syscall restart. We have to do a final recheck right after get_signal_to_deliver() in case the debugger cleared the bit during ptrace_stop(). 3) Clear the bit in trap return so we don't accidently try to set that bit in the real register. As a result we also get a ptrace_{is,clear}_syscall() for sparc32 just like sparc64 has. M68K has this same exact bug, and is now the only other user of the ptrace_signal_deliver hook. It needs to be fixed in the same exact way as sparc. Signed-off-by: David S. Miller <davem@davemloft.net>
2008-05-11 16:07:19 +07:00
int restart_syscall;
bool has_handler;
/* It's a lot of work and synchronization to add a new ptrace
* register for GDB to save and restore in order to get
* orig_i0 correct for syscall restarts when debugging.
*
* Although it should be the case that most of the global
* registers are volatile across a system call, glibc already
* depends upon that fact that we preserve them. So we can't
* just use any global register to save away the orig_i0 value.
*
* In particular %g2, %g3, %g4, and %g5 are all assumed to be
* preserved across a system call trap by various pieces of
* code in glibc.
*
* %g7 is used as the "thread register". %g6 is not used in
* any fixed manner. %g6 is used as a scratch register and
* a compiler temporary, but it's value is never used across
* a system call. Therefore %g6 is usable for orig_i0 storage.
*/
if (pt_regs_is_syscall(regs) &&
(regs->tstate & (TSTATE_XCARRY | TSTATE_ICARRY)))
regs->u_regs[UREG_G6] = orig_i0;
#ifdef CONFIG_COMPAT
if (test_thread_flag(TIF_32BIT)) {
do_signal32(regs);
return;
}
#endif
has_handler = get_signal(&ksig);
sparc: Fix debugger syscall restart interactions. So, forever, we've had this ptrace_signal_deliver implementation which tries to handle all of the nasties that can occur when the debugger looks at a process about to take a signal. It's meant to address all of these issues inside of the kernel so that the debugger need not be mindful of such things. Problem is, this doesn't work. The idea was that we should do the syscall restart business first, so that the debugger captures that state. Otherwise, if the debugger for example saves the child's state, makes the child execute something else, then restores the saved state, we won't handle the syscall restart properly because we lose the "we're in a syscall" state. The code here worked for most cases, but if the debugger actually passes the signal through to the child unaltered, it's possible that we would do a syscall restart when we shouldn't have. In particular this breaks the case of debugging a process under a gdb which is being debugged by yet another gdb. gdb uses sigsuspend to wait for SIGCHLD of the inferior, but if gdb itself is being debugged by a top-level gdb we get a ptrace_stop(). The top-level gdb does a PTRACE_CONT with SIGCHLD to let the inferior gdb see the signal. But ptrace_signal_deliver() assumed the debugger would cancel out the signal and therefore did a syscall restart, because the return error was ERESTARTNOHAND. Fix this by simply making ptrace_signal_deliver() a nop, and providing a way for the debugger to control system call restarting properly: 1) Report a "in syscall" software bit in regs->{tstate,psr}. It is set early on in trap entry to a system call and is fully visible to the debugger via ptrace() and regsets. 2) Test this bit right before doing a syscall restart. We have to do a final recheck right after get_signal_to_deliver() in case the debugger cleared the bit during ptrace_stop(). 3) Clear the bit in trap return so we don't accidently try to set that bit in the real register. As a result we also get a ptrace_{is,clear}_syscall() for sparc32 just like sparc64 has. M68K has this same exact bug, and is now the only other user of the ptrace_signal_deliver hook. It needs to be fixed in the same exact way as sparc. Signed-off-by: David S. Miller <davem@davemloft.net>
2008-05-11 16:07:19 +07:00
restart_syscall = 0;
if (pt_regs_is_syscall(regs) &&
(regs->tstate & (TSTATE_XCARRY | TSTATE_ICARRY))) {
restart_syscall = 1;
orig_i0 = regs->u_regs[UREG_G6];
}
sparc: Fix debugger syscall restart interactions. So, forever, we've had this ptrace_signal_deliver implementation which tries to handle all of the nasties that can occur when the debugger looks at a process about to take a signal. It's meant to address all of these issues inside of the kernel so that the debugger need not be mindful of such things. Problem is, this doesn't work. The idea was that we should do the syscall restart business first, so that the debugger captures that state. Otherwise, if the debugger for example saves the child's state, makes the child execute something else, then restores the saved state, we won't handle the syscall restart properly because we lose the "we're in a syscall" state. The code here worked for most cases, but if the debugger actually passes the signal through to the child unaltered, it's possible that we would do a syscall restart when we shouldn't have. In particular this breaks the case of debugging a process under a gdb which is being debugged by yet another gdb. gdb uses sigsuspend to wait for SIGCHLD of the inferior, but if gdb itself is being debugged by a top-level gdb we get a ptrace_stop(). The top-level gdb does a PTRACE_CONT with SIGCHLD to let the inferior gdb see the signal. But ptrace_signal_deliver() assumed the debugger would cancel out the signal and therefore did a syscall restart, because the return error was ERESTARTNOHAND. Fix this by simply making ptrace_signal_deliver() a nop, and providing a way for the debugger to control system call restarting properly: 1) Report a "in syscall" software bit in regs->{tstate,psr}. It is set early on in trap entry to a system call and is fully visible to the debugger via ptrace() and regsets. 2) Test this bit right before doing a syscall restart. We have to do a final recheck right after get_signal_to_deliver() in case the debugger cleared the bit during ptrace_stop(). 3) Clear the bit in trap return so we don't accidently try to set that bit in the real register. As a result we also get a ptrace_{is,clear}_syscall() for sparc32 just like sparc64 has. M68K has this same exact bug, and is now the only other user of the ptrace_signal_deliver hook. It needs to be fixed in the same exact way as sparc. Signed-off-by: David S. Miller <davem@davemloft.net>
2008-05-11 16:07:19 +07:00
if (has_handler) {
sparc: Fix debugger syscall restart interactions. So, forever, we've had this ptrace_signal_deliver implementation which tries to handle all of the nasties that can occur when the debugger looks at a process about to take a signal. It's meant to address all of these issues inside of the kernel so that the debugger need not be mindful of such things. Problem is, this doesn't work. The idea was that we should do the syscall restart business first, so that the debugger captures that state. Otherwise, if the debugger for example saves the child's state, makes the child execute something else, then restores the saved state, we won't handle the syscall restart properly because we lose the "we're in a syscall" state. The code here worked for most cases, but if the debugger actually passes the signal through to the child unaltered, it's possible that we would do a syscall restart when we shouldn't have. In particular this breaks the case of debugging a process under a gdb which is being debugged by yet another gdb. gdb uses sigsuspend to wait for SIGCHLD of the inferior, but if gdb itself is being debugged by a top-level gdb we get a ptrace_stop(). The top-level gdb does a PTRACE_CONT with SIGCHLD to let the inferior gdb see the signal. But ptrace_signal_deliver() assumed the debugger would cancel out the signal and therefore did a syscall restart, because the return error was ERESTARTNOHAND. Fix this by simply making ptrace_signal_deliver() a nop, and providing a way for the debugger to control system call restarting properly: 1) Report a "in syscall" software bit in regs->{tstate,psr}. It is set early on in trap entry to a system call and is fully visible to the debugger via ptrace() and regsets. 2) Test this bit right before doing a syscall restart. We have to do a final recheck right after get_signal_to_deliver() in case the debugger cleared the bit during ptrace_stop(). 3) Clear the bit in trap return so we don't accidently try to set that bit in the real register. As a result we also get a ptrace_{is,clear}_syscall() for sparc32 just like sparc64 has. M68K has this same exact bug, and is now the only other user of the ptrace_signal_deliver hook. It needs to be fixed in the same exact way as sparc. Signed-off-by: David S. Miller <davem@davemloft.net>
2008-05-11 16:07:19 +07:00
if (restart_syscall)
syscall_restart(orig_i0, regs, &ksig.ka.sa);
signal_setup_done(setup_rt_frame(&ksig, regs), &ksig, 0);
} else {
if (restart_syscall) {
switch (regs->u_regs[UREG_I0]) {
case ERESTARTNOHAND:
case ERESTARTSYS:
case ERESTARTNOINTR:
/* replay the system call when we are done */
regs->u_regs[UREG_I0] = orig_i0;
regs->tpc -= 4;
regs->tnpc -= 4;
pt_regs_clear_syscall(regs);
case ERESTART_RESTARTBLOCK:
regs->u_regs[UREG_G1] = __NR_restart_syscall;
regs->tpc -= 4;
regs->tnpc -= 4;
pt_regs_clear_syscall(regs);
}
}
restore_saved_sigmask();
}
}
void do_notify_resume(struct pt_regs *regs, unsigned long orig_i0, unsigned long thread_info_flags)
{
user_exit();
if (thread_info_flags & _TIF_UPROBE)
uprobe_notify_resume(regs);
if (thread_info_flags & _TIF_SIGPENDING)
do_signal(regs, orig_i0);
if (thread_info_flags & _TIF_NOTIFY_RESUME) {
clear_thread_flag(TIF_NOTIFY_RESUME);
tracehook_notify_resume(regs);
}
user_enter();
}
KEYS: Add a keyctl to install a process's session keyring on its parent [try #6] Add a keyctl to install a process's session keyring onto its parent. This replaces the parent's session keyring. Because the COW credential code does not permit one process to change another process's credentials directly, the change is deferred until userspace next starts executing again. Normally this will be after a wait*() syscall. To support this, three new security hooks have been provided: cred_alloc_blank() to allocate unset security creds, cred_transfer() to fill in the blank security creds and key_session_to_parent() - which asks the LSM if the process may replace its parent's session keyring. The replacement may only happen if the process has the same ownership details as its parent, and the process has LINK permission on the session keyring, and the session keyring is owned by the process, and the LSM permits it. Note that this requires alteration to each architecture's notify_resume path. This has been done for all arches barring blackfin, m68k* and xtensa, all of which need assembly alteration to support TIF_NOTIFY_RESUME. This allows the replacement to be performed at the point the parent process resumes userspace execution. This allows the userspace AFS pioctl emulation to fully emulate newpag() and the VIOCSETTOK and VIOCSETTOK2 pioctls, all of which require the ability to alter the parent process's PAG membership. However, since kAFS doesn't use PAGs per se, but rather dumps the keys into the session keyring, the session keyring of the parent must be replaced if, for example, VIOCSETTOK is passed the newpag flag. This can be tested with the following program: #include <stdio.h> #include <stdlib.h> #include <keyutils.h> #define KEYCTL_SESSION_TO_PARENT 18 #define OSERROR(X, S) do { if ((long)(X) == -1) { perror(S); exit(1); } } while(0) int main(int argc, char **argv) { key_serial_t keyring, key; long ret; keyring = keyctl_join_session_keyring(argv[1]); OSERROR(keyring, "keyctl_join_session_keyring"); key = add_key("user", "a", "b", 1, keyring); OSERROR(key, "add_key"); ret = keyctl(KEYCTL_SESSION_TO_PARENT); OSERROR(ret, "KEYCTL_SESSION_TO_PARENT"); return 0; } Compiled and linked with -lkeyutils, you should see something like: [dhowells@andromeda ~]$ keyctl show Session Keyring -3 --alswrv 4043 4043 keyring: _ses 355907932 --alswrv 4043 -1 \_ keyring: _uid.4043 [dhowells@andromeda ~]$ /tmp/newpag [dhowells@andromeda ~]$ keyctl show Session Keyring -3 --alswrv 4043 4043 keyring: _ses 1055658746 --alswrv 4043 4043 \_ user: a [dhowells@andromeda ~]$ /tmp/newpag hello [dhowells@andromeda ~]$ keyctl show Session Keyring -3 --alswrv 4043 4043 keyring: hello 340417692 --alswrv 4043 4043 \_ user: a Where the test program creates a new session keyring, sticks a user key named 'a' into it and then installs it on its parent. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: James Morris <jmorris@namei.org>
2009-09-02 15:14:21 +07:00