![Dominik Brodowski](/assets/img/avatar_default.png)
compat_sys_*() functions are no longer called from within the kernel on x86 except from the system call table. Linking the system call does not require compat_sys_*() function prototypes at least on x86. Therefore, generate compat_sys_*() prototypes on-the-fly within the COMPAT_SYSCALL_DEFINEx() macro, and remove x86-specific prototypes from various header files. Suggested-by: Andy Lutomirski <luto@kernel.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: David S. Miller <davem@davemloft.net> Cc: netdev@vger.kernel.org Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Andi Kleen <ak@linux.intel.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: x86@kernel.org Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
407 lines
10 KiB
C
407 lines
10 KiB
C
// SPDX-License-Identifier: GPL-2.0
|
|
/*
|
|
* linux/arch/x86_64/ia32/ia32_signal.c
|
|
*
|
|
* Copyright (C) 1991, 1992 Linus Torvalds
|
|
*
|
|
* 1997-11-28 Modified for POSIX.1b signals by Richard Henderson
|
|
* 2000-06-20 Pentium III FXSR, SSE support by Gareth Hughes
|
|
* 2000-12-* x86-64 compatibility mode signal handling by Andi Kleen
|
|
*/
|
|
|
|
#include <linux/sched.h>
|
|
#include <linux/sched/task_stack.h>
|
|
#include <linux/mm.h>
|
|
#include <linux/smp.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/errno.h>
|
|
#include <linux/wait.h>
|
|
#include <linux/unistd.h>
|
|
#include <linux/stddef.h>
|
|
#include <linux/personality.h>
|
|
#include <linux/compat.h>
|
|
#include <linux/binfmts.h>
|
|
#include <asm/ucontext.h>
|
|
#include <linux/uaccess.h>
|
|
#include <asm/fpu/internal.h>
|
|
#include <asm/fpu/signal.h>
|
|
#include <asm/ptrace.h>
|
|
#include <asm/ia32_unistd.h>
|
|
#include <asm/user32.h>
|
|
#include <uapi/asm/sigcontext.h>
|
|
#include <asm/proto.h>
|
|
#include <asm/vdso.h>
|
|
#include <asm/sigframe.h>
|
|
#include <asm/sighandling.h>
|
|
#include <asm/smap.h>
|
|
|
|
/*
|
|
* Do a signal return; undo the signal stack.
|
|
*/
|
|
#define loadsegment_gs(v) load_gs_index(v)
|
|
#define loadsegment_fs(v) loadsegment(fs, v)
|
|
#define loadsegment_ds(v) loadsegment(ds, v)
|
|
#define loadsegment_es(v) loadsegment(es, v)
|
|
|
|
#define get_user_seg(seg) ({ unsigned int v; savesegment(seg, v); v; })
|
|
#define set_user_seg(seg, v) loadsegment_##seg(v)
|
|
|
|
#define COPY(x) { \
|
|
get_user_ex(regs->x, &sc->x); \
|
|
}
|
|
|
|
#define GET_SEG(seg) ({ \
|
|
unsigned short tmp; \
|
|
get_user_ex(tmp, &sc->seg); \
|
|
tmp; \
|
|
})
|
|
|
|
#define COPY_SEG_CPL3(seg) do { \
|
|
regs->seg = GET_SEG(seg) | 3; \
|
|
} while (0)
|
|
|
|
#define RELOAD_SEG(seg) { \
|
|
unsigned int pre = GET_SEG(seg); \
|
|
unsigned int cur = get_user_seg(seg); \
|
|
pre |= 3; \
|
|
if (pre != cur) \
|
|
set_user_seg(seg, pre); \
|
|
}
|
|
|
|
static int ia32_restore_sigcontext(struct pt_regs *regs,
|
|
struct sigcontext_32 __user *sc)
|
|
{
|
|
unsigned int tmpflags, err = 0;
|
|
void __user *buf;
|
|
u32 tmp;
|
|
|
|
/* Always make any pending restarted system calls return -EINTR */
|
|
current->restart_block.fn = do_no_restart_syscall;
|
|
|
|
get_user_try {
|
|
/*
|
|
* Reload fs and gs if they have changed in the signal
|
|
* handler. This does not handle long fs/gs base changes in
|
|
* the handler, but does not clobber them at least in the
|
|
* normal case.
|
|
*/
|
|
RELOAD_SEG(gs);
|
|
RELOAD_SEG(fs);
|
|
RELOAD_SEG(ds);
|
|
RELOAD_SEG(es);
|
|
|
|
COPY(di); COPY(si); COPY(bp); COPY(sp); COPY(bx);
|
|
COPY(dx); COPY(cx); COPY(ip); COPY(ax);
|
|
/* Don't touch extended registers */
|
|
|
|
COPY_SEG_CPL3(cs);
|
|
COPY_SEG_CPL3(ss);
|
|
|
|
get_user_ex(tmpflags, &sc->flags);
|
|
regs->flags = (regs->flags & ~FIX_EFLAGS) | (tmpflags & FIX_EFLAGS);
|
|
/* disable syscall checks */
|
|
regs->orig_ax = -1;
|
|
|
|
get_user_ex(tmp, &sc->fpstate);
|
|
buf = compat_ptr(tmp);
|
|
} get_user_catch(err);
|
|
|
|
err |= fpu__restore_sig(buf, 1);
|
|
|
|
force_iret();
|
|
|
|
return err;
|
|
}
|
|
|
|
asmlinkage long sys32_sigreturn(void)
|
|
{
|
|
struct pt_regs *regs = current_pt_regs();
|
|
struct sigframe_ia32 __user *frame = (struct sigframe_ia32 __user *)(regs->sp-8);
|
|
sigset_t set;
|
|
|
|
if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
|
|
goto badframe;
|
|
if (__get_user(set.sig[0], &frame->sc.oldmask)
|
|
|| (_COMPAT_NSIG_WORDS > 1
|
|
&& __copy_from_user((((char *) &set.sig) + 4),
|
|
&frame->extramask,
|
|
sizeof(frame->extramask))))
|
|
goto badframe;
|
|
|
|
set_current_blocked(&set);
|
|
|
|
if (ia32_restore_sigcontext(regs, &frame->sc))
|
|
goto badframe;
|
|
return regs->ax;
|
|
|
|
badframe:
|
|
signal_fault(regs, frame, "32bit sigreturn");
|
|
return 0;
|
|
}
|
|
|
|
asmlinkage long sys32_rt_sigreturn(void)
|
|
{
|
|
struct pt_regs *regs = current_pt_regs();
|
|
struct rt_sigframe_ia32 __user *frame;
|
|
sigset_t set;
|
|
|
|
frame = (struct rt_sigframe_ia32 __user *)(regs->sp - 4);
|
|
|
|
if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
|
|
goto badframe;
|
|
if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
|
|
goto badframe;
|
|
|
|
set_current_blocked(&set);
|
|
|
|
if (ia32_restore_sigcontext(regs, &frame->uc.uc_mcontext))
|
|
goto badframe;
|
|
|
|
if (compat_restore_altstack(&frame->uc.uc_stack))
|
|
goto badframe;
|
|
|
|
return regs->ax;
|
|
|
|
badframe:
|
|
signal_fault(regs, frame, "32bit rt sigreturn");
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Set up a signal frame.
|
|
*/
|
|
|
|
static int ia32_setup_sigcontext(struct sigcontext_32 __user *sc,
|
|
void __user *fpstate,
|
|
struct pt_regs *regs, unsigned int mask)
|
|
{
|
|
int err = 0;
|
|
|
|
put_user_try {
|
|
put_user_ex(get_user_seg(gs), (unsigned int __user *)&sc->gs);
|
|
put_user_ex(get_user_seg(fs), (unsigned int __user *)&sc->fs);
|
|
put_user_ex(get_user_seg(ds), (unsigned int __user *)&sc->ds);
|
|
put_user_ex(get_user_seg(es), (unsigned int __user *)&sc->es);
|
|
|
|
put_user_ex(regs->di, &sc->di);
|
|
put_user_ex(regs->si, &sc->si);
|
|
put_user_ex(regs->bp, &sc->bp);
|
|
put_user_ex(regs->sp, &sc->sp);
|
|
put_user_ex(regs->bx, &sc->bx);
|
|
put_user_ex(regs->dx, &sc->dx);
|
|
put_user_ex(regs->cx, &sc->cx);
|
|
put_user_ex(regs->ax, &sc->ax);
|
|
put_user_ex(current->thread.trap_nr, &sc->trapno);
|
|
put_user_ex(current->thread.error_code, &sc->err);
|
|
put_user_ex(regs->ip, &sc->ip);
|
|
put_user_ex(regs->cs, (unsigned int __user *)&sc->cs);
|
|
put_user_ex(regs->flags, &sc->flags);
|
|
put_user_ex(regs->sp, &sc->sp_at_signal);
|
|
put_user_ex(regs->ss, (unsigned int __user *)&sc->ss);
|
|
|
|
put_user_ex(ptr_to_compat(fpstate), &sc->fpstate);
|
|
|
|
/* non-iBCS2 extensions.. */
|
|
put_user_ex(mask, &sc->oldmask);
|
|
put_user_ex(current->thread.cr2, &sc->cr2);
|
|
} put_user_catch(err);
|
|
|
|
return err;
|
|
}
|
|
|
|
/*
|
|
* Determine which stack to use..
|
|
*/
|
|
static void __user *get_sigframe(struct ksignal *ksig, struct pt_regs *regs,
|
|
size_t frame_size,
|
|
void __user **fpstate)
|
|
{
|
|
struct fpu *fpu = ¤t->thread.fpu;
|
|
unsigned long sp;
|
|
|
|
/* Default to using normal stack */
|
|
sp = regs->sp;
|
|
|
|
/* This is the X/Open sanctioned signal stack switching. */
|
|
if (ksig->ka.sa.sa_flags & SA_ONSTACK)
|
|
sp = sigsp(sp, ksig);
|
|
/* This is the legacy signal stack switching. */
|
|
else if (regs->ss != __USER32_DS &&
|
|
!(ksig->ka.sa.sa_flags & SA_RESTORER) &&
|
|
ksig->ka.sa.sa_restorer)
|
|
sp = (unsigned long) ksig->ka.sa.sa_restorer;
|
|
|
|
if (fpu->initialized) {
|
|
unsigned long fx_aligned, math_size;
|
|
|
|
sp = fpu__alloc_mathframe(sp, 1, &fx_aligned, &math_size);
|
|
*fpstate = (struct _fpstate_32 __user *) sp;
|
|
if (copy_fpstate_to_sigframe(*fpstate, (void __user *)fx_aligned,
|
|
math_size) < 0)
|
|
return (void __user *) -1L;
|
|
}
|
|
|
|
sp -= frame_size;
|
|
/* Align the stack pointer according to the i386 ABI,
|
|
* i.e. so that on function entry ((sp + 4) & 15) == 0. */
|
|
sp = ((sp + 4) & -16ul) - 4;
|
|
return (void __user *) sp;
|
|
}
|
|
|
|
int ia32_setup_frame(int sig, struct ksignal *ksig,
|
|
compat_sigset_t *set, struct pt_regs *regs)
|
|
{
|
|
struct sigframe_ia32 __user *frame;
|
|
void __user *restorer;
|
|
int err = 0;
|
|
void __user *fpstate = NULL;
|
|
|
|
/* copy_to_user optimizes that into a single 8 byte store */
|
|
static const struct {
|
|
u16 poplmovl;
|
|
u32 val;
|
|
u16 int80;
|
|
} __attribute__((packed)) code = {
|
|
0xb858, /* popl %eax ; movl $...,%eax */
|
|
__NR_ia32_sigreturn,
|
|
0x80cd, /* int $0x80 */
|
|
};
|
|
|
|
frame = get_sigframe(ksig, regs, sizeof(*frame), &fpstate);
|
|
|
|
if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
|
|
return -EFAULT;
|
|
|
|
if (__put_user(sig, &frame->sig))
|
|
return -EFAULT;
|
|
|
|
if (ia32_setup_sigcontext(&frame->sc, fpstate, regs, set->sig[0]))
|
|
return -EFAULT;
|
|
|
|
if (_COMPAT_NSIG_WORDS > 1) {
|
|
if (__copy_to_user(frame->extramask, &set->sig[1],
|
|
sizeof(frame->extramask)))
|
|
return -EFAULT;
|
|
}
|
|
|
|
if (ksig->ka.sa.sa_flags & SA_RESTORER) {
|
|
restorer = ksig->ka.sa.sa_restorer;
|
|
} else {
|
|
/* Return stub is in 32bit vsyscall page */
|
|
if (current->mm->context.vdso)
|
|
restorer = current->mm->context.vdso +
|
|
vdso_image_32.sym___kernel_sigreturn;
|
|
else
|
|
restorer = &frame->retcode;
|
|
}
|
|
|
|
put_user_try {
|
|
put_user_ex(ptr_to_compat(restorer), &frame->pretcode);
|
|
|
|
/*
|
|
* These are actually not used anymore, but left because some
|
|
* gdb versions depend on them as a marker.
|
|
*/
|
|
put_user_ex(*((u64 *)&code), (u64 __user *)frame->retcode);
|
|
} put_user_catch(err);
|
|
|
|
if (err)
|
|
return -EFAULT;
|
|
|
|
/* Set up registers for signal handler */
|
|
regs->sp = (unsigned long) frame;
|
|
regs->ip = (unsigned long) ksig->ka.sa.sa_handler;
|
|
|
|
/* Make -mregparm=3 work */
|
|
regs->ax = sig;
|
|
regs->dx = 0;
|
|
regs->cx = 0;
|
|
|
|
loadsegment(ds, __USER32_DS);
|
|
loadsegment(es, __USER32_DS);
|
|
|
|
regs->cs = __USER32_CS;
|
|
regs->ss = __USER32_DS;
|
|
|
|
return 0;
|
|
}
|
|
|
|
int ia32_setup_rt_frame(int sig, struct ksignal *ksig,
|
|
compat_sigset_t *set, struct pt_regs *regs)
|
|
{
|
|
struct rt_sigframe_ia32 __user *frame;
|
|
void __user *restorer;
|
|
int err = 0;
|
|
void __user *fpstate = NULL;
|
|
|
|
/* __copy_to_user optimizes that into a single 8 byte store */
|
|
static const struct {
|
|
u8 movl;
|
|
u32 val;
|
|
u16 int80;
|
|
u8 pad;
|
|
} __attribute__((packed)) code = {
|
|
0xb8,
|
|
__NR_ia32_rt_sigreturn,
|
|
0x80cd,
|
|
0,
|
|
};
|
|
|
|
frame = get_sigframe(ksig, regs, sizeof(*frame), &fpstate);
|
|
|
|
if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
|
|
return -EFAULT;
|
|
|
|
put_user_try {
|
|
put_user_ex(sig, &frame->sig);
|
|
put_user_ex(ptr_to_compat(&frame->info), &frame->pinfo);
|
|
put_user_ex(ptr_to_compat(&frame->uc), &frame->puc);
|
|
|
|
/* Create the ucontext. */
|
|
if (boot_cpu_has(X86_FEATURE_XSAVE))
|
|
put_user_ex(UC_FP_XSTATE, &frame->uc.uc_flags);
|
|
else
|
|
put_user_ex(0, &frame->uc.uc_flags);
|
|
put_user_ex(0, &frame->uc.uc_link);
|
|
compat_save_altstack_ex(&frame->uc.uc_stack, regs->sp);
|
|
|
|
if (ksig->ka.sa.sa_flags & SA_RESTORER)
|
|
restorer = ksig->ka.sa.sa_restorer;
|
|
else
|
|
restorer = current->mm->context.vdso +
|
|
vdso_image_32.sym___kernel_rt_sigreturn;
|
|
put_user_ex(ptr_to_compat(restorer), &frame->pretcode);
|
|
|
|
/*
|
|
* Not actually used anymore, but left because some gdb
|
|
* versions need it.
|
|
*/
|
|
put_user_ex(*((u64 *)&code), (u64 __user *)frame->retcode);
|
|
} put_user_catch(err);
|
|
|
|
err |= __copy_siginfo_to_user32(&frame->info, &ksig->info, false);
|
|
err |= ia32_setup_sigcontext(&frame->uc.uc_mcontext, fpstate,
|
|
regs, set->sig[0]);
|
|
err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
|
|
|
|
if (err)
|
|
return -EFAULT;
|
|
|
|
/* Set up registers for signal handler */
|
|
regs->sp = (unsigned long) frame;
|
|
regs->ip = (unsigned long) ksig->ka.sa.sa_handler;
|
|
|
|
/* Make -mregparm=3 work */
|
|
regs->ax = sig;
|
|
regs->dx = (unsigned long) &frame->info;
|
|
regs->cx = (unsigned long) &frame->uc;
|
|
|
|
loadsegment(ds, __USER32_DS);
|
|
loadsegment(es, __USER32_DS);
|
|
|
|
regs->cs = __USER32_CS;
|
|
regs->ss = __USER32_DS;
|
|
|
|
return 0;
|
|
}
|