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linux-stable/arch/parisc/kernel/signal32.c
Eric W. Biederman ea64d5acc8 signal: Unify and correct copy_siginfo_to_user32 
Among the existing architecture specific versions of
copy_siginfo_to_user32 there are several different implementation
problems.  Some architectures fail to handle all of the cases in in
the siginfo union.  Some architectures perform a blind copy of the
siginfo union when the si_code is negative.  A blind copy suggests the
data is expected to be in 32bit siginfo format, which means that
receiving such a signal via signalfd won't work, or that the data is
in 64bit siginfo and the code is copying nonsense to userspace.

Create a single instance of copy_siginfo_to_user32 that all of the
architectures can share, and teach it to handle all of the cases in
the siginfo union correctly, with the assumption that siginfo is
stored internally to the kernel is 64bit siginfo format.

A special case is made for x86 x32 format.  This is needed as presence
of both x32 and ia32 on x86_64 results in two different 32bit signal
formats.  By allowing this small special case there winds up being
exactly one code base that needs to be maintained between all of the
architectures.  Vastly increasing the testing base and the chances of
finding bugs.

As the x86 copy of copy_siginfo_to_user32 the call of the x86
signal_compat_build_tests were moved into sigaction_compat_abi, so
that they will keep running.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2018-01-15 19:56:20 -06:00

262 lines
9.5 KiB
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/* Signal support for 32-bit kernel builds
*
* Copyright (C) 2001 Matthew Wilcox <willy at parisc-linux.org>
* Copyright (C) 2006 Kyle McMartin <kyle at parisc-linux.org>
*
* Code was mostly borrowed from kernel/signal.c.
* See kernel/signal.c for additional Copyrights.
*
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include <linux/compat.h>
#include <linux/module.h>
#include <linux/unistd.h>
#include <linux/init.h>
#include <linux/sched.h>
#include <linux/syscalls.h>
#include <linux/types.h>
#include <linux/errno.h>
#include <linux/uaccess.h>
#include "signal32.h"
#define DEBUG_COMPAT_SIG 0
#define DEBUG_COMPAT_SIG_LEVEL 2
#if DEBUG_COMPAT_SIG
#define DBG(LEVEL, ...) \
((DEBUG_COMPAT_SIG_LEVEL >= LEVEL) \
? printk(__VA_ARGS__) : (void) 0)
#else
#define DBG(LEVEL, ...)
#endif
long
restore_sigcontext32(struct compat_sigcontext __user *sc, struct compat_regfile __user * rf,
struct pt_regs *regs)
{
long err = 0;
compat_uint_t compat_reg;
compat_uint_t compat_regt;
int regn;
/* When loading 32-bit values into 64-bit registers make
sure to clear the upper 32-bits */
DBG(2,"restore_sigcontext32: PER_LINUX32 process\n");
DBG(2,"restore_sigcontext32: sc = 0x%p, rf = 0x%p, regs = 0x%p\n", sc, rf, regs);
DBG(2,"restore_sigcontext32: compat_sigcontext is %#lx bytes\n", sizeof(*sc));
for(regn=0; regn < 32; regn++){
err |= __get_user(compat_reg,&sc->sc_gr[regn]);
regs->gr[regn] = compat_reg;
/* Load upper half */
err |= __get_user(compat_regt,&rf->rf_gr[regn]);
regs->gr[regn] = ((u64)compat_regt << 32) | (u64)compat_reg;
DBG(3,"restore_sigcontext32: gr%02d = %#lx (%#x / %#x)\n",
regn, regs->gr[regn], compat_regt, compat_reg);
}
DBG(2,"restore_sigcontext32: sc->sc_fr = 0x%p (%#lx)\n",sc->sc_fr, sizeof(sc->sc_fr));
/* XXX: BE WARNED FR's are 64-BIT! */
err |= __copy_from_user(regs->fr, sc->sc_fr, sizeof(regs->fr));
/* Better safe than sorry, pass __get_user two things of
the same size and let gcc do the upward conversion to
64-bits */
err |= __get_user(compat_reg, &sc->sc_iaoq[0]);
/* Load upper half */
err |= __get_user(compat_regt, &rf->rf_iaoq[0]);
regs->iaoq[0] = ((u64)compat_regt << 32) | (u64)compat_reg;
DBG(2,"restore_sigcontext32: upper half of iaoq[0] = %#lx\n", compat_regt);
DBG(2,"restore_sigcontext32: sc->sc_iaoq[0] = %p => %#x\n",
&sc->sc_iaoq[0], compat_reg);
err |= __get_user(compat_reg, &sc->sc_iaoq[1]);
/* Load upper half */
err |= __get_user(compat_regt, &rf->rf_iaoq[1]);
regs->iaoq[1] = ((u64)compat_regt << 32) | (u64)compat_reg;
DBG(2,"restore_sigcontext32: upper half of iaoq[1] = %#lx\n", compat_regt);
DBG(2,"restore_sigcontext32: sc->sc_iaoq[1] = %p => %#x\n",
&sc->sc_iaoq[1],compat_reg);
DBG(2,"restore_sigcontext32: iaoq is %#lx / %#lx\n",
regs->iaoq[0],regs->iaoq[1]);
err |= __get_user(compat_reg, &sc->sc_iasq[0]);
/* Load the upper half for iasq */
err |= __get_user(compat_regt, &rf->rf_iasq[0]);
regs->iasq[0] = ((u64)compat_regt << 32) | (u64)compat_reg;
DBG(2,"restore_sigcontext32: upper half of iasq[0] = %#lx\n", compat_regt);
err |= __get_user(compat_reg, &sc->sc_iasq[1]);
/* Load the upper half for iasq */
err |= __get_user(compat_regt, &rf->rf_iasq[1]);
regs->iasq[1] = ((u64)compat_regt << 32) | (u64)compat_reg;
DBG(2,"restore_sigcontext32: upper half of iasq[1] = %#lx\n", compat_regt);
DBG(2,"restore_sigcontext32: iasq is %#lx / %#lx\n",
regs->iasq[0],regs->iasq[1]);
err |= __get_user(compat_reg, &sc->sc_sar);
/* Load the upper half for sar */
err |= __get_user(compat_regt, &rf->rf_sar);
regs->sar = ((u64)compat_regt << 32) | (u64)compat_reg;
DBG(2,"restore_sigcontext32: upper_half & sar = %#lx\n", compat_regt);
DBG(2,"restore_sigcontext32: sar is %#lx\n", regs->sar);
DBG(2,"restore_sigcontext32: r28 is %ld\n", regs->gr[28]);
return err;
}
/*
* Set up the sigcontext structure for this process.
* This is not an easy task if the kernel is 64-bit, it will require
* that we examine the process personality to determine if we need to
* truncate for a 32-bit userspace.
*/
long
setup_sigcontext32(struct compat_sigcontext __user *sc, struct compat_regfile __user * rf,
struct pt_regs *regs, int in_syscall)
{
compat_int_t flags = 0;
long err = 0;
compat_uint_t compat_reg;
compat_uint_t compat_regb;
int regn;
if (on_sig_stack((unsigned long) sc))
flags |= PARISC_SC_FLAG_ONSTACK;
if (in_syscall) {
DBG(1,"setup_sigcontext32: in_syscall\n");
flags |= PARISC_SC_FLAG_IN_SYSCALL;
/* Truncate gr31 */
compat_reg = (compat_uint_t)(regs->gr[31]);
/* regs->iaoq is undefined in the syscall return path */
err |= __put_user(compat_reg, &sc->sc_iaoq[0]);
DBG(2,"setup_sigcontext32: sc->sc_iaoq[0] = %p <= %#x\n",
&sc->sc_iaoq[0], compat_reg);
/* Store upper half */
compat_reg = (compat_uint_t)(regs->gr[31] >> 32);
err |= __put_user(compat_reg, &rf->rf_iaoq[0]);
DBG(2,"setup_sigcontext32: upper half iaoq[0] = %#x\n", compat_reg);
compat_reg = (compat_uint_t)(regs->gr[31]+4);
err |= __put_user(compat_reg, &sc->sc_iaoq[1]);
DBG(2,"setup_sigcontext32: sc->sc_iaoq[1] = %p <= %#x\n",
&sc->sc_iaoq[1], compat_reg);
/* Store upper half */
compat_reg = (compat_uint_t)((regs->gr[31]+4) >> 32);
err |= __put_user(compat_reg, &rf->rf_iaoq[1]);
DBG(2,"setup_sigcontext32: upper half iaoq[1] = %#x\n", compat_reg);
/* Truncate sr3 */
compat_reg = (compat_uint_t)(regs->sr[3]);
err |= __put_user(compat_reg, &sc->sc_iasq[0]);
err |= __put_user(compat_reg, &sc->sc_iasq[1]);
/* Store upper half */
compat_reg = (compat_uint_t)(regs->sr[3] >> 32);
err |= __put_user(compat_reg, &rf->rf_iasq[0]);
err |= __put_user(compat_reg, &rf->rf_iasq[1]);
DBG(2,"setup_sigcontext32: upper half iasq[0] = %#x\n", compat_reg);
DBG(2,"setup_sigcontext32: upper half iasq[1] = %#x\n", compat_reg);
DBG(1,"setup_sigcontext32: iaoq %#lx / %#lx\n",
regs->gr[31], regs->gr[31]+4);
} else {
compat_reg = (compat_uint_t)(regs->iaoq[0]);
err |= __put_user(compat_reg, &sc->sc_iaoq[0]);
DBG(2,"setup_sigcontext32: sc->sc_iaoq[0] = %p <= %#x\n",
&sc->sc_iaoq[0], compat_reg);
/* Store upper half */
compat_reg = (compat_uint_t)(regs->iaoq[0] >> 32);
err |= __put_user(compat_reg, &rf->rf_iaoq[0]);
DBG(2,"setup_sigcontext32: upper half iaoq[0] = %#x\n", compat_reg);
compat_reg = (compat_uint_t)(regs->iaoq[1]);
err |= __put_user(compat_reg, &sc->sc_iaoq[1]);
DBG(2,"setup_sigcontext32: sc->sc_iaoq[1] = %p <= %#x\n",
&sc->sc_iaoq[1], compat_reg);
/* Store upper half */
compat_reg = (compat_uint_t)(regs->iaoq[1] >> 32);
err |= __put_user(compat_reg, &rf->rf_iaoq[1]);
DBG(2,"setup_sigcontext32: upper half iaoq[1] = %#x\n", compat_reg);
compat_reg = (compat_uint_t)(regs->iasq[0]);
err |= __put_user(compat_reg, &sc->sc_iasq[0]);
DBG(2,"setup_sigcontext32: sc->sc_iasq[0] = %p <= %#x\n",
&sc->sc_iasq[0], compat_reg);
/* Store upper half */
compat_reg = (compat_uint_t)(regs->iasq[0] >> 32);
err |= __put_user(compat_reg, &rf->rf_iasq[0]);
DBG(2,"setup_sigcontext32: upper half iasq[0] = %#x\n", compat_reg);
compat_reg = (compat_uint_t)(regs->iasq[1]);
err |= __put_user(compat_reg, &sc->sc_iasq[1]);
DBG(2,"setup_sigcontext32: sc->sc_iasq[1] = %p <= %#x\n",
&sc->sc_iasq[1], compat_reg);
/* Store upper half */
compat_reg = (compat_uint_t)(regs->iasq[1] >> 32);
err |= __put_user(compat_reg, &rf->rf_iasq[1]);
DBG(2,"setup_sigcontext32: upper half iasq[1] = %#x\n", compat_reg);
/* Print out the IAOQ for debugging */
DBG(1,"setup_sigcontext32: ia0q %#lx / %#lx\n",
regs->iaoq[0], regs->iaoq[1]);
}
err |= __put_user(flags, &sc->sc_flags);
DBG(1,"setup_sigcontext32: Truncating general registers.\n");
for(regn=0; regn < 32; regn++){
/* Truncate a general register */
compat_reg = (compat_uint_t)(regs->gr[regn]);
err |= __put_user(compat_reg, &sc->sc_gr[regn]);
/* Store upper half */
compat_regb = (compat_uint_t)(regs->gr[regn] >> 32);
err |= __put_user(compat_regb, &rf->rf_gr[regn]);
/* DEBUG: Write out the "upper / lower" register data */
DBG(2,"setup_sigcontext32: gr%02d = %#x / %#x\n", regn,
compat_regb, compat_reg);
}
/* Copy the floating point registers (same size)
XXX: BE WARNED FR's are 64-BIT! */
DBG(1,"setup_sigcontext32: Copying from regs to sc, "
"sc->sc_fr size = %#lx, regs->fr size = %#lx\n",
sizeof(regs->fr), sizeof(sc->sc_fr));
err |= __copy_to_user(sc->sc_fr, regs->fr, sizeof(regs->fr));
compat_reg = (compat_uint_t)(regs->sar);
err |= __put_user(compat_reg, &sc->sc_sar);
DBG(2,"setup_sigcontext32: sar is %#x\n", compat_reg);
/* Store upper half */
compat_reg = (compat_uint_t)(regs->sar >> 32);
err |= __put_user(compat_reg, &rf->rf_sar);
DBG(2,"setup_sigcontext32: upper half sar = %#x\n", compat_reg);
DBG(1,"setup_sigcontext32: r28 is %ld\n", regs->gr[28]);
return err;
}
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