OpenCloudOS-Kernel/arch/x86/um/signal.c

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/*
* Copyright (C) 2003 PathScale, Inc.
* Copyright (C) 2003 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
* Licensed under the GPL
*/
#include <linux/personality.h>
#include <linux/ptrace.h>
#include <linux/kernel.h>
#include <asm/unistd.h>
#include <linux/uaccess.h>
#include <asm/ucontext.h>
#include <frame_kern.h>
#include <registers.h>
#include <skas.h>
#ifdef CONFIG_X86_32
/*
* FPU tag word conversions.
*/
static inline unsigned short twd_i387_to_fxsr(unsigned short twd)
{
unsigned int tmp; /* to avoid 16 bit prefixes in the code */
/* Transform each pair of bits into 01 (valid) or 00 (empty) */
tmp = ~twd;
tmp = (tmp | (tmp>>1)) & 0x5555; /* 0V0V0V0V0V0V0V0V */
/* and move the valid bits to the lower byte. */
tmp = (tmp | (tmp >> 1)) & 0x3333; /* 00VV00VV00VV00VV */
tmp = (tmp | (tmp >> 2)) & 0x0f0f; /* 0000VVVV0000VVVV */
tmp = (tmp | (tmp >> 4)) & 0x00ff; /* 00000000VVVVVVVV */
return tmp;
}
static inline unsigned long twd_fxsr_to_i387(struct user_fxsr_struct *fxsave)
{
struct _fpxreg *st = NULL;
unsigned long twd = (unsigned long) fxsave->twd;
unsigned long tag;
unsigned long ret = 0xffff0000;
int i;
#define FPREG_ADDR(f, n) ((char *)&(f)->st_space + (n) * 16)
for (i = 0; i < 8; i++) {
if (twd & 0x1) {
st = (struct _fpxreg *) FPREG_ADDR(fxsave, i);
switch (st->exponent & 0x7fff) {
case 0x7fff:
tag = 2; /* Special */
break;
case 0x0000:
if ( !st->significand[0] &&
!st->significand[1] &&
!st->significand[2] &&
!st->significand[3] ) {
tag = 1; /* Zero */
} else {
tag = 2; /* Special */
}
break;
default:
if (st->significand[3] & 0x8000) {
tag = 0; /* Valid */
} else {
tag = 2; /* Special */
}
break;
}
} else {
tag = 3; /* Empty */
}
ret |= (tag << (2 * i));
twd = twd >> 1;
}
return ret;
}
static int convert_fxsr_to_user(struct _fpstate __user *buf,
struct user_fxsr_struct *fxsave)
{
unsigned long env[7];
struct _fpreg __user *to;
struct _fpxreg *from;
int i;
env[0] = (unsigned long)fxsave->cwd | 0xffff0000ul;
env[1] = (unsigned long)fxsave->swd | 0xffff0000ul;
env[2] = twd_fxsr_to_i387(fxsave);
env[3] = fxsave->fip;
env[4] = fxsave->fcs | ((unsigned long)fxsave->fop << 16);
env[5] = fxsave->foo;
env[6] = fxsave->fos;
if (__copy_to_user(buf, env, 7 * sizeof(unsigned long)))
return 1;
to = &buf->_st[0];
from = (struct _fpxreg *) &fxsave->st_space[0];
for (i = 0; i < 8; i++, to++, from++) {
unsigned long __user *t = (unsigned long __user *)to;
unsigned long *f = (unsigned long *)from;
if (__put_user(*f, t) ||
__put_user(*(f + 1), t + 1) ||
__put_user(from->exponent, &to->exponent))
return 1;
}
return 0;
}
static int convert_fxsr_from_user(struct user_fxsr_struct *fxsave,
struct _fpstate __user *buf)
{
unsigned long env[7];
struct _fpxreg *to;
struct _fpreg __user *from;
int i;
if (copy_from_user( env, buf, 7 * sizeof(long)))
return 1;
fxsave->cwd = (unsigned short)(env[0] & 0xffff);
fxsave->swd = (unsigned short)(env[1] & 0xffff);
fxsave->twd = twd_i387_to_fxsr((unsigned short)(env[2] & 0xffff));
fxsave->fip = env[3];
fxsave->fop = (unsigned short)((env[4] & 0xffff0000ul) >> 16);
fxsave->fcs = (env[4] & 0xffff);
fxsave->foo = env[5];
fxsave->fos = env[6];
to = (struct _fpxreg *) &fxsave->st_space[0];
from = &buf->_st[0];
for (i = 0; i < 8; i++, to++, from++) {
unsigned long *t = (unsigned long *)to;
unsigned long __user *f = (unsigned long __user *)from;
if (__get_user(*t, f) ||
__get_user(*(t + 1), f + 1) ||
__get_user(to->exponent, &from->exponent))
return 1;
}
return 0;
}
extern int have_fpx_regs;
#endif
static int copy_sc_from_user(struct pt_regs *regs,
struct sigcontext __user *from)
{
struct sigcontext sc;
int err, pid;
/* 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 07:01:14 +08:00
current->restart_block.fn = do_no_restart_syscall;
err = copy_from_user(&sc, from, sizeof(sc));
if (err)
return err;
#define GETREG(regno, regname) regs->regs.gp[HOST_##regno] = sc.regname
#ifdef CONFIG_X86_32
GETREG(GS, gs);
GETREG(FS, fs);
GETREG(ES, es);
GETREG(DS, ds);
#endif
GETREG(DI, di);
GETREG(SI, si);
GETREG(BP, bp);
GETREG(SP, sp);
GETREG(BX, bx);
GETREG(DX, dx);
GETREG(CX, cx);
GETREG(AX, ax);
GETREG(IP, ip);
#ifdef CONFIG_X86_64
GETREG(R8, r8);
GETREG(R9, r9);
GETREG(R10, r10);
GETREG(R11, r11);
GETREG(R12, r12);
GETREG(R13, r13);
GETREG(R14, r14);
GETREG(R15, r15);
#endif
GETREG(CS, cs);
GETREG(EFLAGS, flags);
#ifdef CONFIG_X86_32
GETREG(SS, ss);
#endif
#undef GETREG
pid = userspace_pid[current_thread_info()->cpu];
#ifdef CONFIG_X86_32
if (have_fpx_regs) {
struct user_fxsr_struct fpx;
err = copy_from_user(&fpx,
&((struct _fpstate __user *)sc.fpstate)->_fxsr_env[0],
sizeof(struct user_fxsr_struct));
if (err)
return 1;
err = convert_fxsr_from_user(&fpx, (void *)sc.fpstate);
if (err)
return 1;
err = restore_fpx_registers(pid, (unsigned long *) &fpx);
if (err < 0) {
printk(KERN_ERR "copy_sc_from_user - "
"restore_fpx_registers failed, errno = %d\n",
-err);
return 1;
}
} else
#endif
{
err = copy_from_user(regs->regs.fp, (void *)sc.fpstate,
sizeof(struct _xstate));
if (err)
return 1;
}
return 0;
}
static int copy_sc_to_user(struct sigcontext __user *to,
struct _xstate __user *to_fp, struct pt_regs *regs,
unsigned long mask)
{
struct sigcontext sc;
[PATCH] uml: S390 preparation, abstract host page fault data This patch removes the arch-specific fault/trap-infos from thread and skas-regs. It adds a new struct faultinfo, that is arch-specific defined in sysdep/faultinfo.h. The structure is inserted in thread.arch and thread.regs.skas and thread.regs.tt Now, segv and other trap-handlers can copy the contents from regs.X.faultinfo to thread.arch.faultinfo with one simple assignment. Also, the number of macros necessary is reduced to FAULT_ADDRESS(struct faultinfo) extracts the faulting address from faultinfo FAULT_WRITE(struct faultinfo) extracts the "is_write" flag SEGV_IS_FIXABLE(struct faultinfo) is true for the fixable segvs, i.e. (TRAP == 14) on i386 UPT_FAULTINFO(regs) result is (struct faultinfo *) to the faultinfo in regs->skas.faultinfo GET_FAULTINFO_FROM_SC(struct faultinfo, struct sigcontext *) copies the relevant parts of the sigcontext to struct faultinfo. On SIGSEGV, call user_signal() instead of handle_segv(), if the architecture provides the information needed in PTRACE_FAULTINFO, or if PTRACE_FAULTINFO is missing, because segv-stub will provide the info. The benefit of the change is, that in case of a non-fixable SIGSEGV, we can give user processes a SIGSEGV, instead of possibly looping on pagefault handling. Since handle_segv() sikked arch_fixup() implicitly by passing ip==0 to segv(), I changed segv() to call arch_fixup() only, if !is_user. Signed-off-by: Bodo Stroesser <bstroesser@fujitsu-siemens.com> Signed-off-by: Jeff Dike <jdike@addtoit.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-05-06 07:15:31 +08:00
struct faultinfo * fi = &current->thread.arch.faultinfo;
int err, pid;
memset(&sc, 0, sizeof(struct sigcontext));
#define PUTREG(regno, regname) sc.regname = regs->regs.gp[HOST_##regno]
#ifdef CONFIG_X86_32
PUTREG(GS, gs);
PUTREG(FS, fs);
PUTREG(ES, es);
PUTREG(DS, ds);
#endif
PUTREG(DI, di);
PUTREG(SI, si);
PUTREG(BP, bp);
PUTREG(SP, sp);
PUTREG(BX, bx);
PUTREG(DX, dx);
PUTREG(CX, cx);
PUTREG(AX, ax);
#ifdef CONFIG_X86_64
PUTREG(R8, r8);
PUTREG(R9, r9);
PUTREG(R10, r10);
PUTREG(R11, r11);
PUTREG(R12, r12);
PUTREG(R13, r13);
PUTREG(R14, r14);
PUTREG(R15, r15);
#endif
sc.cr2 = fi->cr2;
sc.err = fi->error_code;
sc.trapno = fi->trap_no;
PUTREG(IP, ip);
PUTREG(CS, cs);
PUTREG(EFLAGS, flags);
#ifdef CONFIG_X86_32
PUTREG(SP, sp_at_signal);
PUTREG(SS, ss);
#endif
#undef PUTREG
sc.oldmask = mask;
sc.fpstate = (unsigned long)to_fp;
err = copy_to_user(to, &sc, sizeof(struct sigcontext));
if (err)
return 1;
pid = userspace_pid[current_thread_info()->cpu];
#ifdef CONFIG_X86_32
if (have_fpx_regs) {
struct user_fxsr_struct fpx;
err = save_fpx_registers(pid, (unsigned long *) &fpx);
if (err < 0){
printk(KERN_ERR "copy_sc_to_user - save_fpx_registers "
"failed, errno = %d\n", err);
return 1;
}
err = convert_fxsr_to_user(&to_fp->fpstate, &fpx);
if (err)
return 1;
err |= __put_user(fpx.swd, &to_fp->fpstate.status);
err |= __put_user(X86_FXSR_MAGIC, &to_fp->fpstate.magic);
if (err)
return 1;
if (copy_to_user(&to_fp->fpstate._fxsr_env[0], &fpx,
sizeof(struct user_fxsr_struct)))
return 1;
} else
#endif
{
if (copy_to_user(to_fp, regs->regs.fp, sizeof(struct _xstate)))
return 1;
}
return 0;
}
#ifdef CONFIG_X86_32
static int copy_ucontext_to_user(struct ucontext __user *uc,
struct _xstate __user *fp, sigset_t *set,
unsigned long sp)
{
int err = 0;
err |= __save_altstack(&uc->uc_stack, sp);
err |= copy_sc_to_user(&uc->uc_mcontext, fp, &current->thread.regs, 0);
err |= copy_to_user(&uc->uc_sigmask, set, sizeof(*set));
return err;
}
struct sigframe
{
char __user *pretcode;
int sig;
struct sigcontext sc;
struct _xstate fpstate;
unsigned long extramask[_NSIG_WORDS-1];
char retcode[8];
};
struct rt_sigframe
{
char __user *pretcode;
int sig;
struct siginfo __user *pinfo;
void __user *puc;
struct siginfo info;
struct ucontext uc;
struct _xstate fpstate;
char retcode[8];
};
int setup_signal_stack_sc(unsigned long stack_top, struct ksignal *ksig,
struct pt_regs *regs, sigset_t *mask)
{
struct sigframe __user *frame;
void __user *restorer;
int err = 0, sig = ksig->sig;
/* This is the same calculation as i386 - ((sp + 4) & 15) == 0 */
stack_top = ((stack_top + 4) & -16UL) - 4;
frame = (struct sigframe __user *) stack_top - 1;
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 10:57:57 +08:00
if (!access_ok(frame, sizeof(*frame)))
return 1;
restorer = frame->retcode;
if (ksig->ka.sa.sa_flags & SA_RESTORER)
restorer = ksig->ka.sa.sa_restorer;
err |= __put_user(restorer, &frame->pretcode);
err |= __put_user(sig, &frame->sig);
err |= copy_sc_to_user(&frame->sc, &frame->fpstate, regs, mask->sig[0]);
if (_NSIG_WORDS > 1)
err |= __copy_to_user(&frame->extramask, &mask->sig[1],
sizeof(frame->extramask));
/*
* This is popl %eax ; movl $,%eax ; int $0x80
*
* WE DO NOT USE IT ANY MORE! It's only left here for historical
* reasons and because gdb uses it as a signature to notice
* signal handler stack frames.
*/
err |= __put_user(0xb858, (short __user *)(frame->retcode+0));
err |= __put_user(__NR_sigreturn, (int __user *)(frame->retcode+2));
err |= __put_user(0x80cd, (short __user *)(frame->retcode+6));
if (err)
return err;
PT_REGS_SP(regs) = (unsigned long) frame;
PT_REGS_IP(regs) = (unsigned long) ksig->ka.sa.sa_handler;
PT_REGS_AX(regs) = (unsigned long) sig;
PT_REGS_DX(regs) = (unsigned long) 0;
PT_REGS_CX(regs) = (unsigned long) 0;
return 0;
}
int setup_signal_stack_si(unsigned long stack_top, struct ksignal *ksig,
struct pt_regs *regs, sigset_t *mask)
{
struct rt_sigframe __user *frame;
void __user *restorer;
int err = 0, sig = ksig->sig;
stack_top &= -8UL;
frame = (struct rt_sigframe __user *) stack_top - 1;
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 10:57:57 +08:00
if (!access_ok(frame, sizeof(*frame)))
return 1;
restorer = frame->retcode;
if (ksig->ka.sa.sa_flags & SA_RESTORER)
restorer = ksig->ka.sa.sa_restorer;
err |= __put_user(restorer, &frame->pretcode);
err |= __put_user(sig, &frame->sig);
err |= __put_user(&frame->info, &frame->pinfo);
err |= __put_user(&frame->uc, &frame->puc);
err |= copy_siginfo_to_user(&frame->info, &ksig->info);
err |= copy_ucontext_to_user(&frame->uc, &frame->fpstate, mask,
PT_REGS_SP(regs));
/*
* This is movl $,%eax ; int $0x80
*
* WE DO NOT USE IT ANY MORE! It's only left here for historical
* reasons and because gdb uses it as a signature to notice
* signal handler stack frames.
*/
err |= __put_user(0xb8, (char __user *)(frame->retcode+0));
err |= __put_user(__NR_rt_sigreturn, (int __user *)(frame->retcode+1));
err |= __put_user(0x80cd, (short __user *)(frame->retcode+5));
if (err)
return err;
PT_REGS_SP(regs) = (unsigned long) frame;
PT_REGS_IP(regs) = (unsigned long) ksig->ka.sa.sa_handler;
PT_REGS_AX(regs) = (unsigned long) sig;
PT_REGS_DX(regs) = (unsigned long) &frame->info;
PT_REGS_CX(regs) = (unsigned long) &frame->uc;
return 0;
}
long sys_sigreturn(void)
{
unsigned long sp = PT_REGS_SP(&current->thread.regs);
struct sigframe __user *frame = (struct sigframe __user *)(sp - 8);
sigset_t set;
struct sigcontext __user *sc = &frame->sc;
int sig_size = (_NSIG_WORDS - 1) * sizeof(unsigned long);
if (copy_from_user(&set.sig[0], &sc->oldmask, sizeof(set.sig[0])) ||
copy_from_user(&set.sig[1], frame->extramask, sig_size))
goto segfault;
set_current_blocked(&set);
if (copy_sc_from_user(&current->thread.regs, sc))
goto segfault;
/* Avoid ERESTART handling */
PT_REGS_SYSCALL_NR(&current->thread.regs) = -1;
return PT_REGS_SYSCALL_RET(&current->thread.regs);
segfault:
force_sig(SIGSEGV);
return 0;
}
#else
struct rt_sigframe
{
char __user *pretcode;
struct ucontext uc;
struct siginfo info;
struct _xstate fpstate;
};
int setup_signal_stack_si(unsigned long stack_top, struct ksignal *ksig,
struct pt_regs *regs, sigset_t *set)
{
struct rt_sigframe __user *frame;
int err = 0, sig = ksig->sig;
unsigned long fp_to;
frame = (struct rt_sigframe __user *)
round_down(stack_top - sizeof(struct rt_sigframe), 16);
/* Subtract 128 for a red zone and 8 for proper alignment */
frame = (struct rt_sigframe __user *) ((unsigned long) frame - 128 - 8);
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 10:57:57 +08:00
if (!access_ok(frame, sizeof(*frame)))
goto out;
if (ksig->ka.sa.sa_flags & SA_SIGINFO) {
err |= copy_siginfo_to_user(&frame->info, &ksig->info);
if (err)
goto out;
}
/* Create the ucontext. */
err |= __put_user(0, &frame->uc.uc_flags);
err |= __put_user(0, &frame->uc.uc_link);
err |= __save_altstack(&frame->uc.uc_stack, PT_REGS_SP(regs));
err |= copy_sc_to_user(&frame->uc.uc_mcontext, &frame->fpstate, regs,
set->sig[0]);
fp_to = (unsigned long)&frame->fpstate;
err |= __put_user(fp_to, &frame->uc.uc_mcontext.fpstate);
if (sizeof(*set) == 16) {
err |= __put_user(set->sig[0], &frame->uc.uc_sigmask.sig[0]);
err |= __put_user(set->sig[1], &frame->uc.uc_sigmask.sig[1]);
}
else
err |= __copy_to_user(&frame->uc.uc_sigmask, set,
sizeof(*set));
/*
* Set up to return from userspace. If provided, use a stub
* already in userspace.
*/
/* x86-64 should always use SA_RESTORER. */
if (ksig->ka.sa.sa_flags & SA_RESTORER)
err |= __put_user((void *)ksig->ka.sa.sa_restorer,
&frame->pretcode);
else
/* could use a vstub here */
return err;
if (err)
return err;
PT_REGS_SP(regs) = (unsigned long) frame;
PT_REGS_DI(regs) = sig;
/* In case the signal handler was declared without prototypes */
PT_REGS_AX(regs) = 0;
/*
* This also works for non SA_SIGINFO handlers because they expect the
* next argument after the signal number on the stack.
*/
PT_REGS_SI(regs) = (unsigned long) &frame->info;
PT_REGS_DX(regs) = (unsigned long) &frame->uc;
PT_REGS_IP(regs) = (unsigned long) ksig->ka.sa.sa_handler;
out:
return err;
}
#endif
long sys_rt_sigreturn(void)
{
unsigned long sp = PT_REGS_SP(&current->thread.regs);
struct rt_sigframe __user *frame =
(struct rt_sigframe __user *)(sp - sizeof(long));
struct ucontext __user *uc = &frame->uc;
sigset_t set;
if (copy_from_user(&set, &uc->uc_sigmask, sizeof(set)))
goto segfault;
set_current_blocked(&set);
if (copy_sc_from_user(&current->thread.regs, &uc->uc_mcontext))
goto segfault;
/* Avoid ERESTART handling */
PT_REGS_SYSCALL_NR(&current->thread.regs) = -1;
return PT_REGS_SYSCALL_RET(&current->thread.regs);
segfault:
force_sig(SIGSEGV);
return 0;
}