linux-brain/arch/mips/kernel/signal_o32.c

291 lines
7.3 KiB
C
Raw Normal View History

/*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
* Copyright (C) 1991, 1992 Linus Torvalds
* Copyright (C) 1994 - 2000, 2006 Ralf Baechle
* Copyright (C) 1999, 2000 Silicon Graphics, Inc.
* Copyright (C) 2016, Imagination Technologies Ltd.
*/
#include <linux/compiler.h>
#include <linux/errno.h>
#include <linux/signal.h>
#include <linux/sched/signal.h>
#include <linux/uaccess.h>
#include <asm/abi.h>
#include <asm/compat-signal.h>
#include <asm/dsp.h>
#include <asm/sim.h>
#include <asm/unistd.h>
#include "signal-common.h"
/*
* Including <asm/unistd.h> would give use the 64-bit syscall numbers ...
*/
#define __NR_O32_restart_syscall 4253
struct sigframe32 {
u32 sf_ass[4]; /* argument save space for o32 */
u32 sf_pad[2]; /* Was: signal trampoline */
struct sigcontext32 sf_sc;
compat_sigset_t sf_mask;
};
struct ucontext32 {
u32 uc_flags;
s32 uc_link;
compat_stack_t uc_stack;
struct sigcontext32 uc_mcontext;
compat_sigset_t uc_sigmask; /* mask last for extensibility */
};
struct rt_sigframe32 {
u32 rs_ass[4]; /* argument save space for o32 */
u32 rs_pad[2]; /* Was: signal trampoline */
compat_siginfo_t rs_info;
struct ucontext32 rs_uc;
};
static int setup_sigcontext32(struct pt_regs *regs,
struct sigcontext32 __user *sc)
{
int err = 0;
int i;
err |= __put_user(regs->cp0_epc, &sc->sc_pc);
err |= __put_user(0, &sc->sc_regs[0]);
for (i = 1; i < 32; i++)
err |= __put_user(regs->regs[i], &sc->sc_regs[i]);
err |= __put_user(regs->hi, &sc->sc_mdhi);
err |= __put_user(regs->lo, &sc->sc_mdlo);
if (cpu_has_dsp) {
err |= __put_user(rddsp(DSP_MASK), &sc->sc_dsp);
err |= __put_user(mfhi1(), &sc->sc_hi1);
err |= __put_user(mflo1(), &sc->sc_lo1);
err |= __put_user(mfhi2(), &sc->sc_hi2);
err |= __put_user(mflo2(), &sc->sc_lo2);
err |= __put_user(mfhi3(), &sc->sc_hi3);
err |= __put_user(mflo3(), &sc->sc_lo3);
}
/*
* Save FPU state to signal context. Signal handler
* will "inherit" current FPU state.
*/
err |= protected_save_fp_context(sc);
return err;
}
static int restore_sigcontext32(struct pt_regs *regs,
struct sigcontext32 __user *sc)
{
int err = 0;
s32 treg;
int i;
/* Always make any pending restarted system calls return -EINTR */
current->restart_block.fn = do_no_restart_syscall;
err |= __get_user(regs->cp0_epc, &sc->sc_pc);
err |= __get_user(regs->hi, &sc->sc_mdhi);
err |= __get_user(regs->lo, &sc->sc_mdlo);
if (cpu_has_dsp) {
err |= __get_user(treg, &sc->sc_hi1); mthi1(treg);
err |= __get_user(treg, &sc->sc_lo1); mtlo1(treg);
err |= __get_user(treg, &sc->sc_hi2); mthi2(treg);
err |= __get_user(treg, &sc->sc_lo2); mtlo2(treg);
err |= __get_user(treg, &sc->sc_hi3); mthi3(treg);
err |= __get_user(treg, &sc->sc_lo3); mtlo3(treg);
err |= __get_user(treg, &sc->sc_dsp); wrdsp(treg, DSP_MASK);
}
for (i = 1; i < 32; i++)
err |= __get_user(regs->regs[i], &sc->sc_regs[i]);
return err ?: protected_restore_fp_context(sc);
}
static int setup_frame_32(void *sig_return, struct ksignal *ksig,
struct pt_regs *regs, sigset_t *set)
{
struct sigframe32 __user *frame;
int err = 0;
frame = get_sigframe(ksig, regs, sizeof(*frame));
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 11:57:57 +09:00
if (!access_ok(frame, sizeof (*frame)))
return -EFAULT;
err |= setup_sigcontext32(regs, &frame->sf_sc);
err |= __copy_conv_sigset_to_user(&frame->sf_mask, set);
if (err)
return -EFAULT;
/*
* Arguments to signal handler:
*
* a0 = signal number
* a1 = 0 (should be cause)
* a2 = pointer to struct sigcontext
*
* $25 and c0_epc point to the signal handler, $29 points to the
* struct sigframe.
*/
regs->regs[ 4] = ksig->sig;
regs->regs[ 5] = 0;
regs->regs[ 6] = (unsigned long) &frame->sf_sc;
regs->regs[29] = (unsigned long) frame;
regs->regs[31] = (unsigned long) sig_return;
regs->cp0_epc = regs->regs[25] = (unsigned long) ksig->ka.sa.sa_handler;
DEBUGP("SIG deliver (%s:%d): sp=0x%p pc=0x%lx ra=0x%lx\n",
current->comm, current->pid,
frame, regs->cp0_epc, regs->regs[31]);
return 0;
}
asmlinkage void sys32_rt_sigreturn(void)
{
struct rt_sigframe32 __user *frame;
struct pt_regs *regs;
sigset_t set;
int sig;
regs = current_pt_regs();
frame = (struct rt_sigframe32 __user *)regs->regs[29];
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 11:57:57 +09:00
if (!access_ok(frame, sizeof(*frame)))
goto badframe;
if (__copy_conv_sigset_from_user(&set, &frame->rs_uc.uc_sigmask))
goto badframe;
set_current_blocked(&set);
sig = restore_sigcontext32(regs, &frame->rs_uc.uc_mcontext);
if (sig < 0)
goto badframe;
else if (sig)
force_sig(sig);
if (compat_restore_altstack(&frame->rs_uc.uc_stack))
goto badframe;
/*
* Don't let your children do this ...
*/
__asm__ __volatile__(
"move\t$29, %0\n\t"
"j\tsyscall_exit"
: /* no outputs */
: "r" (regs));
/* Unreached */
badframe:
force_sig(SIGSEGV);
}
static int setup_rt_frame_32(void *sig_return, struct ksignal *ksig,
struct pt_regs *regs, sigset_t *set)
{
struct rt_sigframe32 __user *frame;
int err = 0;
frame = get_sigframe(ksig, regs, sizeof(*frame));
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 11:57:57 +09:00
if (!access_ok(frame, sizeof (*frame)))
return -EFAULT;
/* Convert (siginfo_t -> compat_siginfo_t) and copy to user. */
err |= copy_siginfo_to_user32(&frame->rs_info, &ksig->info);
/* Create the ucontext. */
err |= __put_user(0, &frame->rs_uc.uc_flags);
err |= __put_user(0, &frame->rs_uc.uc_link);
err |= __compat_save_altstack(&frame->rs_uc.uc_stack, regs->regs[29]);
err |= setup_sigcontext32(regs, &frame->rs_uc.uc_mcontext);
err |= __copy_conv_sigset_to_user(&frame->rs_uc.uc_sigmask, set);
if (err)
return -EFAULT;
/*
* Arguments to signal handler:
*
* a0 = signal number
* a1 = 0 (should be cause)
* a2 = pointer to ucontext
*
* $25 and c0_epc point to the signal handler, $29 points to
* the struct rt_sigframe32.
*/
regs->regs[ 4] = ksig->sig;
regs->regs[ 5] = (unsigned long) &frame->rs_info;
regs->regs[ 6] = (unsigned long) &frame->rs_uc;
regs->regs[29] = (unsigned long) frame;
regs->regs[31] = (unsigned long) sig_return;
regs->cp0_epc = regs->regs[25] = (unsigned long) ksig->ka.sa.sa_handler;
DEBUGP("SIG deliver (%s:%d): sp=0x%p pc=0x%lx ra=0x%lx\n",
current->comm, current->pid,
frame, regs->cp0_epc, regs->regs[31]);
return 0;
}
/*
* o32 compatibility on 64-bit kernels, without DSP ASE
*/
struct mips_abi mips_abi_32 = {
.setup_frame = setup_frame_32,
.setup_rt_frame = setup_rt_frame_32,
.restart = __NR_O32_restart_syscall,
.off_sc_fpregs = offsetof(struct sigcontext32, sc_fpregs),
.off_sc_fpc_csr = offsetof(struct sigcontext32, sc_fpc_csr),
.off_sc_used_math = offsetof(struct sigcontext32, sc_used_math),
.vdso = &vdso_image_o32,
};
asmlinkage void sys32_sigreturn(void)
{
struct sigframe32 __user *frame;
struct pt_regs *regs;
sigset_t blocked;
int sig;
regs = current_pt_regs();
frame = (struct sigframe32 __user *)regs->regs[29];
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 11:57:57 +09:00
if (!access_ok(frame, sizeof(*frame)))
goto badframe;
if (__copy_conv_sigset_from_user(&blocked, &frame->sf_mask))
goto badframe;
set_current_blocked(&blocked);
sig = restore_sigcontext32(regs, &frame->sf_sc);
if (sig < 0)
goto badframe;
else if (sig)
force_sig(sig);
/*
* Don't let your children do this ...
*/
__asm__ __volatile__(
"move\t$29, %0\n\t"
"j\tsyscall_exit"
: /* no outputs */
: "r" (regs));
/* Unreached */
badframe:
force_sig(SIGSEGV);
}