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Diffstat (limited to 'arch/x86/ia32/ia32_signal.c')
-rw-r--r--arch/x86/ia32/ia32_signal.c562
1 files changed, 562 insertions, 0 deletions
diff --git a/arch/x86/ia32/ia32_signal.c b/arch/x86/ia32/ia32_signal.c
new file mode 100644
index 00000000..4f5bfacf
--- /dev/null
+++ b/arch/x86/ia32/ia32_signal.c
@@ -0,0 +1,562 @@
+/*
+ * 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/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 <asm/uaccess.h>
+#include <asm/i387.h>
+#include <asm/fpu-internal.h>
+#include <asm/ptrace.h>
+#include <asm/ia32_unistd.h>
+#include <asm/user32.h>
+#include <asm/sigcontext32.h>
+#include <asm/proto.h>
+#include <asm/vdso.h>
+#include <asm/sigframe.h>
+#include <asm/sighandling.h>
+#include <asm/sys_ia32.h>
+
+#define FIX_EFLAGS __FIX_EFLAGS
+
+int copy_siginfo_to_user32(compat_siginfo_t __user *to, siginfo_t *from)
+{
+ int err = 0;
+ bool ia32 = test_thread_flag(TIF_IA32);
+
+ if (!access_ok(VERIFY_WRITE, to, sizeof(compat_siginfo_t)))
+ return -EFAULT;
+
+ put_user_try {
+ /* If you change siginfo_t structure, please make sure that
+ this code is fixed accordingly.
+ It should never copy any pad contained in the structure
+ to avoid security leaks, but must copy the generic
+ 3 ints plus the relevant union member. */
+ put_user_ex(from->si_signo, &to->si_signo);
+ put_user_ex(from->si_errno, &to->si_errno);
+ put_user_ex((short)from->si_code, &to->si_code);
+
+ if (from->si_code < 0) {
+ put_user_ex(from->si_pid, &to->si_pid);
+ put_user_ex(from->si_uid, &to->si_uid);
+ put_user_ex(ptr_to_compat(from->si_ptr), &to->si_ptr);
+ } else {
+ /*
+ * First 32bits of unions are always present:
+ * si_pid === si_band === si_tid === si_addr(LS half)
+ */
+ put_user_ex(from->_sifields._pad[0],
+ &to->_sifields._pad[0]);
+ switch (from->si_code >> 16) {
+ case __SI_FAULT >> 16:
+ break;
+ case __SI_CHLD >> 16:
+ if (ia32) {
+ put_user_ex(from->si_utime, &to->si_utime);
+ put_user_ex(from->si_stime, &to->si_stime);
+ } else {
+ put_user_ex(from->si_utime, &to->_sifields._sigchld_x32._utime);
+ put_user_ex(from->si_stime, &to->_sifields._sigchld_x32._stime);
+ }
+ put_user_ex(from->si_status, &to->si_status);
+ /* FALL THROUGH */
+ default:
+ case __SI_KILL >> 16:
+ put_user_ex(from->si_uid, &to->si_uid);
+ break;
+ case __SI_POLL >> 16:
+ put_user_ex(from->si_fd, &to->si_fd);
+ break;
+ case __SI_TIMER >> 16:
+ put_user_ex(from->si_overrun, &to->si_overrun);
+ put_user_ex(ptr_to_compat(from->si_ptr),
+ &to->si_ptr);
+ break;
+ /* This is not generated by the kernel as of now. */
+ case __SI_RT >> 16:
+ case __SI_MESGQ >> 16:
+ put_user_ex(from->si_uid, &to->si_uid);
+ put_user_ex(from->si_int, &to->si_int);
+ break;
+ }
+ }
+ } put_user_catch(err);
+
+ return err;
+}
+
+int copy_siginfo_from_user32(siginfo_t *to, compat_siginfo_t __user *from)
+{
+ int err = 0;
+ u32 ptr32;
+
+ if (!access_ok(VERIFY_READ, from, sizeof(compat_siginfo_t)))
+ return -EFAULT;
+
+ get_user_try {
+ get_user_ex(to->si_signo, &from->si_signo);
+ get_user_ex(to->si_errno, &from->si_errno);
+ get_user_ex(to->si_code, &from->si_code);
+
+ get_user_ex(to->si_pid, &from->si_pid);
+ get_user_ex(to->si_uid, &from->si_uid);
+ get_user_ex(ptr32, &from->si_ptr);
+ to->si_ptr = compat_ptr(ptr32);
+ } get_user_catch(err);
+
+ return err;
+}
+
+asmlinkage long sys32_sigsuspend(int history0, int history1, old_sigset_t mask)
+{
+ sigset_t blocked;
+
+ current->saved_sigmask = current->blocked;
+
+ mask &= _BLOCKABLE;
+ siginitset(&blocked, mask);
+ set_current_blocked(&blocked);
+
+ current->state = TASK_INTERRUPTIBLE;
+ schedule();
+
+ set_restore_sigmask();
+ return -ERESTARTNOHAND;
+}
+
+asmlinkage long sys32_sigaltstack(const stack_ia32_t __user *uss_ptr,
+ stack_ia32_t __user *uoss_ptr,
+ struct pt_regs *regs)
+{
+ stack_t uss, uoss;
+ int ret, err = 0;
+ mm_segment_t seg;
+
+ if (uss_ptr) {
+ u32 ptr;
+
+ memset(&uss, 0, sizeof(stack_t));
+ if (!access_ok(VERIFY_READ, uss_ptr, sizeof(stack_ia32_t)))
+ return -EFAULT;
+
+ get_user_try {
+ get_user_ex(ptr, &uss_ptr->ss_sp);
+ get_user_ex(uss.ss_flags, &uss_ptr->ss_flags);
+ get_user_ex(uss.ss_size, &uss_ptr->ss_size);
+ } get_user_catch(err);
+
+ if (err)
+ return -EFAULT;
+ uss.ss_sp = compat_ptr(ptr);
+ }
+ seg = get_fs();
+ set_fs(KERNEL_DS);
+ ret = do_sigaltstack(uss_ptr ? &uss : NULL, &uoss, regs->sp);
+ set_fs(seg);
+ if (ret >= 0 && uoss_ptr) {
+ if (!access_ok(VERIFY_WRITE, uoss_ptr, sizeof(stack_ia32_t)))
+ return -EFAULT;
+
+ put_user_try {
+ put_user_ex(ptr_to_compat(uoss.ss_sp), &uoss_ptr->ss_sp);
+ put_user_ex(uoss.ss_flags, &uoss_ptr->ss_flags);
+ put_user_ex(uoss.ss_size, &uoss_ptr->ss_size);
+ } put_user_catch(err);
+
+ if (err)
+ ret = -EFAULT;
+ }
+ return ret;
+}
+
+/*
+ * 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_ia32 __user *sc,
+ unsigned int *pax)
+{
+ unsigned int tmpflags, err = 0;
+ void __user *buf;
+ u32 tmp;
+
+ /* Always make any pending restarted system calls return -EINTR */
+ current_thread_info()->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);
+ /* 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);
+ err |= restore_i387_xstate_ia32(buf);
+
+ get_user_ex(*pax, &sc->ax);
+ } get_user_catch(err);
+
+ return err;
+}
+
+asmlinkage long sys32_sigreturn(struct pt_regs *regs)
+{
+ struct sigframe_ia32 __user *frame = (struct sigframe_ia32 __user *)(regs->sp-8);
+ sigset_t set;
+ unsigned int ax;
+
+ 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;
+
+ sigdelsetmask(&set, ~_BLOCKABLE);
+ set_current_blocked(&set);
+
+ if (ia32_restore_sigcontext(regs, &frame->sc, &ax))
+ goto badframe;
+ return ax;
+
+badframe:
+ signal_fault(regs, frame, "32bit sigreturn");
+ return 0;
+}
+
+asmlinkage long sys32_rt_sigreturn(struct pt_regs *regs)
+{
+ struct rt_sigframe_ia32 __user *frame;
+ sigset_t set;
+ unsigned int ax;
+ struct pt_regs tregs;
+
+ 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;
+
+ sigdelsetmask(&set, ~_BLOCKABLE);
+ set_current_blocked(&set);
+
+ if (ia32_restore_sigcontext(regs, &frame->uc.uc_mcontext, &ax))
+ goto badframe;
+
+ tregs = *regs;
+ if (sys32_sigaltstack(&frame->uc.uc_stack, NULL, &tregs) == -EFAULT)
+ goto badframe;
+
+ return ax;
+
+badframe:
+ signal_fault(regs, frame, "32bit rt sigreturn");
+ return 0;
+}
+
+/*
+ * Set up a signal frame.
+ */
+
+static int ia32_setup_sigcontext(struct sigcontext_ia32 __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 k_sigaction *ka, struct pt_regs *regs,
+ size_t frame_size,
+ void **fpstate)
+{
+ unsigned long sp;
+
+ /* Default to using normal stack */
+ sp = regs->sp;
+
+ /* This is the X/Open sanctioned signal stack switching. */
+ if (ka->sa.sa_flags & SA_ONSTACK) {
+ if (sas_ss_flags(sp) == 0)
+ sp = current->sas_ss_sp + current->sas_ss_size;
+ }
+
+ /* This is the legacy signal stack switching. */
+ else if ((regs->ss & 0xffff) != __USER32_DS &&
+ !(ka->sa.sa_flags & SA_RESTORER) &&
+ ka->sa.sa_restorer)
+ sp = (unsigned long) ka->sa.sa_restorer;
+
+ if (used_math()) {
+ sp = sp - sig_xstate_ia32_size;
+ *fpstate = (struct _fpstate_ia32 *) sp;
+ if (save_i387_xstate_ia32(*fpstate) < 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 k_sigaction *ka,
+ 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(ka, 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 (ka->sa.sa_flags & SA_RESTORER) {
+ restorer = ka->sa.sa_restorer;
+ } else {
+ /* Return stub is in 32bit vsyscall page */
+ if (current->mm->context.vdso)
+ restorer = VDSO32_SYMBOL(current->mm->context.vdso,
+ 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 *)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) 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 k_sigaction *ka, siginfo_t *info,
+ 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(ka, 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);
+ err |= copy_siginfo_to_user32(&frame->info, info);
+
+ /* Create the ucontext. */
+ if (cpu_has_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);
+ put_user_ex(current->sas_ss_sp, &frame->uc.uc_stack.ss_sp);
+ put_user_ex(sas_ss_flags(regs->sp),
+ &frame->uc.uc_stack.ss_flags);
+ put_user_ex(current->sas_ss_size, &frame->uc.uc_stack.ss_size);
+ 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 (ka->sa.sa_flags & SA_RESTORER)
+ restorer = ka->sa.sa_restorer;
+ else
+ restorer = VDSO32_SYMBOL(current->mm->context.vdso,
+ 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 *)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) 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;
+}
generated by cgit (git 2.34.1) at 2025-01-15 17:47:18 +0000