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-rw-r--r--arch/x86/ia32/ia32_signal.c617
1 files changed, 617 insertions, 0 deletions
diff --git a/arch/x86/ia32/ia32_signal.c b/arch/x86/ia32/ia32_signal.c
new file mode 100644
index 000000000000..6ea19c25f90d
--- /dev/null
+++ b/arch/x86/ia32/ia32_signal.c
@@ -0,0 +1,617 @@
+/*
+ * 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/signal.h>
+#include <linux/errno.h>
+#include <linux/wait.h>
+#include <linux/ptrace.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/ia32.h>
+#include <asm/ptrace.h>
+#include <asm/ia32_unistd.h>
+#include <asm/user32.h>
+#include <asm/sigcontext32.h>
+#include <asm/fpu32.h>
+#include <asm/proto.h>
+#include <asm/vsyscall32.h>
+
+#define DEBUG_SIG 0
+
+#define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
+
+asmlinkage int do_signal(struct pt_regs *regs, sigset_t *oldset);
+void signal_fault(struct pt_regs *regs, void __user *frame, char *where);
+
+int copy_siginfo_to_user32(compat_siginfo_t __user *to, siginfo_t *from)
+{
+ int err;
+ if (!access_ok (VERIFY_WRITE, to, sizeof(compat_siginfo_t)))
+ return -EFAULT;
+
+ /* 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. */
+ err = __put_user(from->si_signo, &to->si_signo);
+ err |= __put_user(from->si_errno, &to->si_errno);
+ err |= __put_user((short)from->si_code, &to->si_code);
+
+ if (from->si_code < 0) {
+ err |= __put_user(from->si_pid, &to->si_pid);
+ err |= __put_user(from->si_uid, &to->si_uid);
+ err |= __put_user(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) */
+ err |= __put_user(from->_sifields._pad[0], &to->_sifields._pad[0]);
+ switch (from->si_code >> 16) {
+ case __SI_FAULT >> 16:
+ break;
+ case __SI_CHLD >> 16:
+ err |= __put_user(from->si_utime, &to->si_utime);
+ err |= __put_user(from->si_stime, &to->si_stime);
+ err |= __put_user(from->si_status, &to->si_status);
+ /* FALL THROUGH */
+ default:
+ case __SI_KILL >> 16:
+ err |= __put_user(from->si_uid, &to->si_uid);
+ break;
+ case __SI_POLL >> 16:
+ err |= __put_user(from->si_fd, &to->si_fd);
+ break;
+ case __SI_TIMER >> 16:
+ err |= __put_user(from->si_overrun, &to->si_overrun);
+ err |= __put_user(ptr_to_compat(from->si_ptr),
+ &to->si_ptr);
+ break;
+ case __SI_RT >> 16: /* This is not generated by the kernel as of now. */
+ case __SI_MESGQ >> 16:
+ err |= __put_user(from->si_uid, &to->si_uid);
+ err |= __put_user(from->si_int, &to->si_int);
+ break;
+ }
+ }
+ return err;
+}
+
+int copy_siginfo_from_user32(siginfo_t *to, compat_siginfo_t __user *from)
+{
+ int err;
+ u32 ptr32;
+ if (!access_ok (VERIFY_READ, from, sizeof(compat_siginfo_t)))
+ return -EFAULT;
+
+ err = __get_user(to->si_signo, &from->si_signo);
+ err |= __get_user(to->si_errno, &from->si_errno);
+ err |= __get_user(to->si_code, &from->si_code);
+
+ err |= __get_user(to->si_pid, &from->si_pid);
+ err |= __get_user(to->si_uid, &from->si_uid);
+ err |= __get_user(ptr32, &from->si_ptr);
+ to->si_ptr = compat_ptr(ptr32);
+
+ return err;
+}
+
+asmlinkage long
+sys32_sigsuspend(int history0, int history1, old_sigset_t mask)
+{
+ mask &= _BLOCKABLE;
+ spin_lock_irq(&current->sighand->siglock);
+ current->saved_sigmask = current->blocked;
+ siginitset(&current->blocked, mask);
+ recalc_sigpending();
+ spin_unlock_irq(&current->sighand->siglock);
+
+ current->state = TASK_INTERRUPTIBLE;
+ schedule();
+ set_thread_flag(TIF_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;
+ 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)) ||
+ __get_user(ptr, &uss_ptr->ss_sp) ||
+ __get_user(uss.ss_flags, &uss_ptr->ss_flags) ||
+ __get_user(uss.ss_size, &uss_ptr->ss_size))
+ return -EFAULT;
+ uss.ss_sp = compat_ptr(ptr);
+ }
+ seg = get_fs();
+ set_fs(KERNEL_DS);
+ ret = do_sigaltstack(uss_ptr ? &uss : NULL, &uoss, regs->rsp);
+ set_fs(seg);
+ if (ret >= 0 && uoss_ptr) {
+ if (!access_ok(VERIFY_WRITE,uoss_ptr,sizeof(stack_ia32_t)) ||
+ __put_user(ptr_to_compat(uoss.ss_sp), &uoss_ptr->ss_sp) ||
+ __put_user(uoss.ss_flags, &uoss_ptr->ss_flags) ||
+ __put_user(uoss.ss_size, &uoss_ptr->ss_size))
+ ret = -EFAULT;
+ }
+ return ret;
+}
+
+/*
+ * Do a signal return; undo the signal stack.
+ */
+
+struct sigframe
+{
+ u32 pretcode;
+ int sig;
+ struct sigcontext_ia32 sc;
+ struct _fpstate_ia32 fpstate;
+ unsigned int extramask[_COMPAT_NSIG_WORDS-1];
+ char retcode[8];
+};
+
+struct rt_sigframe
+{
+ u32 pretcode;
+ int sig;
+ u32 pinfo;
+ u32 puc;
+ compat_siginfo_t info;
+ struct ucontext_ia32 uc;
+ struct _fpstate_ia32 fpstate;
+ char retcode[8];
+};
+
+static int
+ia32_restore_sigcontext(struct pt_regs *regs, struct sigcontext_ia32 __user *sc, unsigned int *peax)
+{
+ unsigned int err = 0;
+
+ /* Always make any pending restarted system calls return -EINTR */
+ current_thread_info()->restart_block.fn = do_no_restart_syscall;
+
+#if DEBUG_SIG
+ printk("SIG restore_sigcontext: sc=%p err(%x) eip(%x) cs(%x) flg(%x)\n",
+ sc, sc->err, sc->eip, sc->cs, sc->eflags);
+#endif
+#define COPY(x) { \
+ unsigned int reg; \
+ err |= __get_user(reg, &sc->e ##x); \
+ regs->r ## x = reg; \
+}
+
+#define RELOAD_SEG(seg,mask) \
+ { unsigned int cur; \
+ unsigned short pre; \
+ err |= __get_user(pre, &sc->seg); \
+ asm volatile("movl %%" #seg ",%0" : "=r" (cur)); \
+ pre |= mask; \
+ if (pre != cur) loadsegment(seg,pre); }
+
+ /* 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. */
+
+ {
+ unsigned gs, oldgs;
+ err |= __get_user(gs, &sc->gs);
+ gs |= 3;
+ asm("movl %%gs,%0" : "=r" (oldgs));
+ if (gs != oldgs)
+ load_gs_index(gs);
+ }
+ RELOAD_SEG(fs,3);
+ RELOAD_SEG(ds,3);
+ RELOAD_SEG(es,3);
+
+ COPY(di); COPY(si); COPY(bp); COPY(sp); COPY(bx);
+ COPY(dx); COPY(cx); COPY(ip);
+ /* Don't touch extended registers */
+
+ err |= __get_user(regs->cs, &sc->cs);
+ regs->cs |= 3;
+ err |= __get_user(regs->ss, &sc->ss);
+ regs->ss |= 3;
+
+ {
+ unsigned int tmpflags;
+ err |= __get_user(tmpflags, &sc->eflags);
+ regs->eflags = (regs->eflags & ~0x40DD5) | (tmpflags & 0x40DD5);
+ regs->orig_rax = -1; /* disable syscall checks */
+ }
+
+ {
+ u32 tmp;
+ struct _fpstate_ia32 __user * buf;
+ err |= __get_user(tmp, &sc->fpstate);
+ buf = compat_ptr(tmp);
+ if (buf) {
+ if (!access_ok(VERIFY_READ, buf, sizeof(*buf)))
+ goto badframe;
+ err |= restore_i387_ia32(current, buf, 0);
+ } else {
+ struct task_struct *me = current;
+ if (used_math()) {
+ clear_fpu(me);
+ clear_used_math();
+ }
+ }
+ }
+
+ {
+ u32 tmp;
+ err |= __get_user(tmp, &sc->eax);
+ *peax = tmp;
+ }
+ return err;
+
+badframe:
+ return 1;
+}
+
+asmlinkage long sys32_sigreturn(struct pt_regs *regs)
+{
+ struct sigframe __user *frame = (struct sigframe __user *)(regs->rsp-8);
+ sigset_t set;
+ unsigned int eax;
+
+ 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);
+ spin_lock_irq(&current->sighand->siglock);
+ current->blocked = set;
+ recalc_sigpending();
+ spin_unlock_irq(&current->sighand->siglock);
+
+ if (ia32_restore_sigcontext(regs, &frame->sc, &eax))
+ goto badframe;
+ return eax;
+
+badframe:
+ signal_fault(regs, frame, "32bit sigreturn");
+ return 0;
+}
+
+asmlinkage long sys32_rt_sigreturn(struct pt_regs *regs)
+{
+ struct rt_sigframe __user *frame;
+ sigset_t set;
+ unsigned int eax;
+ struct pt_regs tregs;
+
+ frame = (struct rt_sigframe __user *)(regs->rsp - 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);
+ spin_lock_irq(&current->sighand->siglock);
+ current->blocked = set;
+ recalc_sigpending();
+ spin_unlock_irq(&current->sighand->siglock);
+
+ if (ia32_restore_sigcontext(regs, &frame->uc.uc_mcontext, &eax))
+ goto badframe;
+
+ tregs = *regs;
+ if (sys32_sigaltstack(&frame->uc.uc_stack, NULL, &tregs) == -EFAULT)
+ goto badframe;
+
+ return eax;
+
+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, struct _fpstate_ia32 __user *fpstate,
+ struct pt_regs *regs, unsigned int mask)
+{
+ int tmp, err = 0;
+
+ tmp = 0;
+ __asm__("movl %%gs,%0" : "=r"(tmp): "0"(tmp));
+ err |= __put_user(tmp, (unsigned int __user *)&sc->gs);
+ __asm__("movl %%fs,%0" : "=r"(tmp): "0"(tmp));
+ err |= __put_user(tmp, (unsigned int __user *)&sc->fs);
+ __asm__("movl %%ds,%0" : "=r"(tmp): "0"(tmp));
+ err |= __put_user(tmp, (unsigned int __user *)&sc->ds);
+ __asm__("movl %%es,%0" : "=r"(tmp): "0"(tmp));
+ err |= __put_user(tmp, (unsigned int __user *)&sc->es);
+
+ err |= __put_user((u32)regs->rdi, &sc->edi);
+ err |= __put_user((u32)regs->rsi, &sc->esi);
+ err |= __put_user((u32)regs->rbp, &sc->ebp);
+ err |= __put_user((u32)regs->rsp, &sc->esp);
+ err |= __put_user((u32)regs->rbx, &sc->ebx);
+ err |= __put_user((u32)regs->rdx, &sc->edx);
+ err |= __put_user((u32)regs->rcx, &sc->ecx);
+ err |= __put_user((u32)regs->rax, &sc->eax);
+ err |= __put_user((u32)regs->cs, &sc->cs);
+ err |= __put_user((u32)regs->ss, &sc->ss);
+ err |= __put_user(current->thread.trap_no, &sc->trapno);
+ err |= __put_user(current->thread.error_code, &sc->err);
+ err |= __put_user((u32)regs->rip, &sc->eip);
+ err |= __put_user((u32)regs->eflags, &sc->eflags);
+ err |= __put_user((u32)regs->rsp, &sc->esp_at_signal);
+
+ tmp = save_i387_ia32(current, fpstate, regs, 0);
+ if (tmp < 0)
+ err = -EFAULT;
+ else {
+ clear_used_math();
+ stts();
+ err |= __put_user(ptr_to_compat(tmp ? fpstate : NULL),
+ &sc->fpstate);
+ }
+
+ /* non-iBCS2 extensions.. */
+ err |= __put_user(mask, &sc->oldmask);
+ err |= __put_user(current->thread.cr2, &sc->cr2);
+
+ return err;
+}
+
+/*
+ * Determine which stack to use..
+ */
+static void __user *
+get_sigframe(struct k_sigaction *ka, struct pt_regs * regs, size_t frame_size)
+{
+ unsigned long rsp;
+
+ /* Default to using normal stack */
+ rsp = regs->rsp;
+
+ /* This is the X/Open sanctioned signal stack switching. */
+ if (ka->sa.sa_flags & SA_ONSTACK) {
+ if (sas_ss_flags(rsp) == 0)
+ rsp = current->sas_ss_sp + current->sas_ss_size;
+ }
+
+ /* This is the legacy signal stack switching. */
+ else if ((regs->ss & 0xffff) != __USER_DS &&
+ !(ka->sa.sa_flags & SA_RESTORER) &&
+ ka->sa.sa_restorer) {
+ rsp = (unsigned long) ka->sa.sa_restorer;
+ }
+
+ rsp -= frame_size;
+ /* Align the stack pointer according to the i386 ABI,
+ * i.e. so that on function entry ((sp + 4) & 15) == 0. */
+ rsp = ((rsp + 4) & -16ul) - 4;
+ return (void __user *) rsp;
+}
+
+int ia32_setup_frame(int sig, struct k_sigaction *ka,
+ compat_sigset_t *set, struct pt_regs * regs)
+{
+ struct sigframe __user *frame;
+ int err = 0;
+
+ frame = get_sigframe(ka, regs, sizeof(*frame));
+
+ if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
+ goto give_sigsegv;
+
+ err |= __put_user(sig, &frame->sig);
+ if (err)
+ goto give_sigsegv;
+
+ err |= ia32_setup_sigcontext(&frame->sc, &frame->fpstate, regs,
+ set->sig[0]);
+ if (err)
+ goto give_sigsegv;
+
+ if (_COMPAT_NSIG_WORDS > 1) {
+ err |= __copy_to_user(frame->extramask, &set->sig[1],
+ sizeof(frame->extramask));
+ }
+ if (err)
+ goto give_sigsegv;
+
+ /* Return stub is in 32bit vsyscall page */
+ {
+ void __user *restorer;
+ if (current->binfmt->hasvdso)
+ restorer = VSYSCALL32_SIGRETURN;
+ else
+ restorer = (void *)&frame->retcode;
+ if (ka->sa.sa_flags & SA_RESTORER)
+ restorer = ka->sa.sa_restorer;
+ err |= __put_user(ptr_to_compat(restorer), &frame->pretcode);
+ }
+ /* These are actually not used anymore, but left because some
+ gdb versions depend on them as a marker. */
+ {
+ /* copy_to_user optimizes that into a single 8 byte store */
+ static const struct {
+ u16 poplmovl;
+ u32 val;
+ u16 int80;
+ u16 pad;
+ } __attribute__((packed)) code = {
+ 0xb858, /* popl %eax ; movl $...,%eax */
+ __NR_ia32_sigreturn,
+ 0x80cd, /* int $0x80 */
+ 0,
+ };
+ err |= __copy_to_user(frame->retcode, &code, 8);
+ }
+ if (err)
+ goto give_sigsegv;
+
+ /* Set up registers for signal handler */
+ regs->rsp = (unsigned long) frame;
+ regs->rip = (unsigned long) ka->sa.sa_handler;
+
+ /* Make -mregparm=3 work */
+ regs->rax = sig;
+ regs->rdx = 0;
+ regs->rcx = 0;
+
+ asm volatile("movl %0,%%ds" :: "r" (__USER32_DS));
+ asm volatile("movl %0,%%es" :: "r" (__USER32_DS));
+
+ regs->cs = __USER32_CS;
+ regs->ss = __USER32_DS;
+
+ set_fs(USER_DS);
+ regs->eflags &= ~TF_MASK;
+ if (test_thread_flag(TIF_SINGLESTEP))
+ ptrace_notify(SIGTRAP);
+
+#if DEBUG_SIG
+ printk("SIG deliver (%s:%d): sp=%p pc=%lx ra=%u\n",
+ current->comm, current->pid, frame, regs->rip, frame->pretcode);
+#endif
+
+ return 0;
+
+give_sigsegv:
+ force_sigsegv(sig, current);
+ return -EFAULT;
+}
+
+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 __user *frame;
+ int err = 0;
+
+ frame = get_sigframe(ka, regs, sizeof(*frame));
+
+ if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
+ goto give_sigsegv;
+
+ {
+ struct exec_domain *ed = current_thread_info()->exec_domain;
+ err |= __put_user((ed
+ && ed->signal_invmap
+ && sig < 32
+ ? ed->signal_invmap[sig]
+ : sig),
+ &frame->sig);
+ }
+ err |= __put_user(ptr_to_compat(&frame->info), &frame->pinfo);
+ err |= __put_user(ptr_to_compat(&frame->uc), &frame->puc);
+ err |= copy_siginfo_to_user32(&frame->info, info);
+ if (err)
+ goto give_sigsegv;
+
+ /* Create the ucontext. */
+ err |= __put_user(0, &frame->uc.uc_flags);
+ err |= __put_user(0, &frame->uc.uc_link);
+ err |= __put_user(current->sas_ss_sp, &frame->uc.uc_stack.ss_sp);
+ err |= __put_user(sas_ss_flags(regs->rsp),
+ &frame->uc.uc_stack.ss_flags);
+ err |= __put_user(current->sas_ss_size, &frame->uc.uc_stack.ss_size);
+ err |= ia32_setup_sigcontext(&frame->uc.uc_mcontext, &frame->fpstate,
+ regs, set->sig[0]);
+ err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
+ if (err)
+ goto give_sigsegv;
+
+
+ {
+ void __user *restorer = VSYSCALL32_RTSIGRETURN;
+ if (ka->sa.sa_flags & SA_RESTORER)
+ restorer = ka->sa.sa_restorer;
+ err |= __put_user(ptr_to_compat(restorer), &frame->pretcode);
+ }
+
+ /* This is movl $,%eax ; int $0x80 */
+ /* Not actually used anymore, but left because some gdb versions
+ need it. */
+ {
+ /* __copy_to_user optimizes that into a single 8 byte store */
+ static const struct {
+ u8 movl;
+ u32 val;
+ u16 int80;
+ u16 pad;
+ u8 pad2;
+ } __attribute__((packed)) code = {
+ 0xb8,
+ __NR_ia32_rt_sigreturn,
+ 0x80cd,
+ 0,
+ };
+ err |= __copy_to_user(frame->retcode, &code, 8);
+ }
+ if (err)
+ goto give_sigsegv;
+
+ /* Set up registers for signal handler */
+ regs->rsp = (unsigned long) frame;
+ regs->rip = (unsigned long) ka->sa.sa_handler;
+
+ /* Make -mregparm=3 work */
+ regs->rax = sig;
+ regs->rdx = (unsigned long) &frame->info;
+ regs->rcx = (unsigned long) &frame->uc;
+
+ /* Make -mregparm=3 work */
+ regs->rax = sig;
+ regs->rdx = (unsigned long) &frame->info;
+ regs->rcx = (unsigned long) &frame->uc;
+
+ asm volatile("movl %0,%%ds" :: "r" (__USER32_DS));
+ asm volatile("movl %0,%%es" :: "r" (__USER32_DS));
+
+ regs->cs = __USER32_CS;
+ regs->ss = __USER32_DS;
+
+ set_fs(USER_DS);
+ regs->eflags &= ~TF_MASK;
+ if (test_thread_flag(TIF_SINGLESTEP))
+ ptrace_notify(SIGTRAP);
+
+#if DEBUG_SIG
+ printk("SIG deliver (%s:%d): sp=%p pc=%lx ra=%u\n",
+ current->comm, current->pid, frame, regs->rip, frame->pretcode);
+#endif
+
+ return 0;
+
+give_sigsegv:
+ force_sigsegv(sig, current);
+ return -EFAULT;
+}
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.