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-rw-r--r--arch/sparc/kernel/signal_32.c565
1 files changed, 565 insertions, 0 deletions
diff --git a/arch/sparc/kernel/signal_32.c b/arch/sparc/kernel/signal_32.c
new file mode 100644
index 000000000..89b93c713
--- /dev/null
+++ b/arch/sparc/kernel/signal_32.c
@@ -0,0 +1,565 @@
+// SPDX-License-Identifier: GPL-2.0
+/* linux/arch/sparc/kernel/signal.c
+ *
+ * Copyright (C) 1991, 1992 Linus Torvalds
+ * Copyright (C) 1995 David S. Miller (davem@caip.rutgers.edu)
+ * Copyright (C) 1996 Miguel de Icaza (miguel@nuclecu.unam.mx)
+ * Copyright (C) 1997 Eddie C. Dost (ecd@skynet.be)
+ */
+
+#include <linux/sched.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/mm.h>
+#include <linux/tty.h>
+#include <linux/smp.h>
+#include <linux/binfmts.h> /* do_coredum */
+#include <linux/bitops.h>
+#include <linux/resume_user_mode.h>
+
+#include <linux/uaccess.h>
+#include <asm/ptrace.h>
+#include <asm/cacheflush.h> /* flush_sig_insns */
+#include <asm/switch_to.h>
+
+#include "sigutil.h"
+#include "kernel.h"
+
+extern void fpsave(unsigned long *fpregs, unsigned long *fsr,
+ void *fpqueue, unsigned long *fpqdepth);
+extern void fpload(unsigned long *fpregs, unsigned long *fsr);
+
+struct signal_frame {
+ struct sparc_stackf ss;
+ __siginfo32_t info;
+ __siginfo_fpu_t __user *fpu_save;
+ unsigned long insns[2] __attribute__ ((aligned (8)));
+ unsigned int extramask[_NSIG_WORDS - 1];
+ unsigned int extra_size; /* Should be 0 */
+ __siginfo_rwin_t __user *rwin_save;
+} __attribute__((aligned(8)));
+
+struct rt_signal_frame {
+ struct sparc_stackf ss;
+ siginfo_t info;
+ struct pt_regs regs;
+ sigset_t mask;
+ __siginfo_fpu_t __user *fpu_save;
+ unsigned int insns[2];
+ stack_t stack;
+ unsigned int extra_size; /* Should be 0 */
+ __siginfo_rwin_t __user *rwin_save;
+} __attribute__((aligned(8)));
+
+/* Align macros */
+#define SF_ALIGNEDSZ (((sizeof(struct signal_frame) + 7) & (~7)))
+#define RT_ALIGNEDSZ (((sizeof(struct rt_signal_frame) + 7) & (~7)))
+
+/* Checks if the fp is valid. We always build signal frames which are
+ * 16-byte aligned, therefore we can always enforce that the restore
+ * frame has that property as well.
+ */
+static inline bool invalid_frame_pointer(void __user *fp, int fplen)
+{
+ if ((((unsigned long) fp) & 15) || !access_ok(fp, fplen))
+ return true;
+
+ return false;
+}
+
+asmlinkage void do_sigreturn(struct pt_regs *regs)
+{
+ unsigned long up_psr, pc, npc, ufp;
+ struct signal_frame __user *sf;
+ sigset_t set;
+ __siginfo_fpu_t __user *fpu_save;
+ __siginfo_rwin_t __user *rwin_save;
+ int err;
+
+ /* Always make any pending restarted system calls return -EINTR */
+ current->restart_block.fn = do_no_restart_syscall;
+
+ synchronize_user_stack();
+
+ sf = (struct signal_frame __user *) regs->u_regs[UREG_FP];
+
+ /* 1. Make sure we are not getting garbage from the user */
+ if (invalid_frame_pointer(sf, sizeof(*sf)))
+ goto segv_and_exit;
+
+ if (get_user(ufp, &sf->info.si_regs.u_regs[UREG_FP]))
+ goto segv_and_exit;
+
+ if (ufp & 0x7)
+ goto segv_and_exit;
+
+ err = __get_user(pc, &sf->info.si_regs.pc);
+ err |= __get_user(npc, &sf->info.si_regs.npc);
+
+ if ((pc | npc) & 3)
+ goto segv_and_exit;
+
+ /* 2. Restore the state */
+ up_psr = regs->psr;
+ err |= __copy_from_user(regs, &sf->info.si_regs, sizeof(struct pt_regs));
+
+ /* User can only change condition codes and FPU enabling in %psr. */
+ regs->psr = (up_psr & ~(PSR_ICC | PSR_EF))
+ | (regs->psr & (PSR_ICC | PSR_EF));
+
+ /* Prevent syscall restart. */
+ pt_regs_clear_syscall(regs);
+
+ err |= __get_user(fpu_save, &sf->fpu_save);
+ if (fpu_save)
+ err |= restore_fpu_state(regs, fpu_save);
+ err |= __get_user(rwin_save, &sf->rwin_save);
+ if (rwin_save)
+ err |= restore_rwin_state(rwin_save);
+
+ /* This is pretty much atomic, no amount locking would prevent
+ * the races which exist anyways.
+ */
+ err |= __get_user(set.sig[0], &sf->info.si_mask);
+ err |= __copy_from_user(&set.sig[1], &sf->extramask,
+ (_NSIG_WORDS-1) * sizeof(unsigned int));
+
+ if (err)
+ goto segv_and_exit;
+
+ set_current_blocked(&set);
+ return;
+
+segv_and_exit:
+ force_sig(SIGSEGV);
+}
+
+asmlinkage void do_rt_sigreturn(struct pt_regs *regs)
+{
+ struct rt_signal_frame __user *sf;
+ unsigned int psr, pc, npc, ufp;
+ __siginfo_fpu_t __user *fpu_save;
+ __siginfo_rwin_t __user *rwin_save;
+ sigset_t set;
+ int err;
+
+ synchronize_user_stack();
+ sf = (struct rt_signal_frame __user *) regs->u_regs[UREG_FP];
+ if (invalid_frame_pointer(sf, sizeof(*sf)))
+ goto segv;
+
+ if (get_user(ufp, &sf->regs.u_regs[UREG_FP]))
+ goto segv;
+
+ if (ufp & 0x7)
+ goto segv;
+
+ err = __get_user(pc, &sf->regs.pc);
+ err |= __get_user(npc, &sf->regs.npc);
+ err |= ((pc | npc) & 0x03);
+
+ err |= __get_user(regs->y, &sf->regs.y);
+ err |= __get_user(psr, &sf->regs.psr);
+
+ err |= __copy_from_user(&regs->u_regs[UREG_G1],
+ &sf->regs.u_regs[UREG_G1], 15 * sizeof(u32));
+
+ regs->psr = (regs->psr & ~PSR_ICC) | (psr & PSR_ICC);
+
+ /* Prevent syscall restart. */
+ pt_regs_clear_syscall(regs);
+
+ err |= __get_user(fpu_save, &sf->fpu_save);
+ if (!err && fpu_save)
+ err |= restore_fpu_state(regs, fpu_save);
+ err |= __copy_from_user(&set, &sf->mask, sizeof(sigset_t));
+ err |= restore_altstack(&sf->stack);
+
+ if (err)
+ goto segv;
+
+ regs->pc = pc;
+ regs->npc = npc;
+
+ err |= __get_user(rwin_save, &sf->rwin_save);
+ if (!err && rwin_save) {
+ if (restore_rwin_state(rwin_save))
+ goto segv;
+ }
+
+ set_current_blocked(&set);
+ return;
+segv:
+ force_sig(SIGSEGV);
+}
+
+static inline void __user *get_sigframe(struct ksignal *ksig, struct pt_regs *regs, unsigned long framesize)
+{
+ unsigned long sp = regs->u_regs[UREG_FP];
+
+ /*
+ * If we are on the alternate signal stack and would overflow it, don't.
+ * Return an always-bogus address instead so we will die with SIGSEGV.
+ */
+ if (on_sig_stack(sp) && !likely(on_sig_stack(sp - framesize)))
+ return (void __user *) -1L;
+
+ /* This is the X/Open sanctioned signal stack switching. */
+ sp = sigsp(sp, ksig) - framesize;
+
+ /* Always align the stack frame. This handles two cases. First,
+ * sigaltstack need not be mindful of platform specific stack
+ * alignment. Second, if we took this signal because the stack
+ * is not aligned properly, we'd like to take the signal cleanly
+ * and report that.
+ */
+ sp &= ~15UL;
+
+ return (void __user *) sp;
+}
+
+static int setup_frame(struct ksignal *ksig, struct pt_regs *regs,
+ sigset_t *oldset)
+{
+ struct signal_frame __user *sf;
+ int sigframe_size, err, wsaved;
+ void __user *tail;
+
+ /* 1. Make sure everything is clean */
+ synchronize_user_stack();
+
+ wsaved = current_thread_info()->w_saved;
+
+ sigframe_size = sizeof(*sf);
+ if (used_math())
+ sigframe_size += sizeof(__siginfo_fpu_t);
+ if (wsaved)
+ sigframe_size += sizeof(__siginfo_rwin_t);
+
+ sf = (struct signal_frame __user *)
+ get_sigframe(ksig, regs, sigframe_size);
+
+ if (invalid_frame_pointer(sf, sigframe_size)) {
+ force_exit_sig(SIGILL);
+ return -EINVAL;
+ }
+
+ tail = sf + 1;
+
+ /* 2. Save the current process state */
+ err = __copy_to_user(&sf->info.si_regs, regs, sizeof(struct pt_regs));
+
+ err |= __put_user(0, &sf->extra_size);
+
+ if (used_math()) {
+ __siginfo_fpu_t __user *fp = tail;
+ tail += sizeof(*fp);
+ err |= save_fpu_state(regs, fp);
+ err |= __put_user(fp, &sf->fpu_save);
+ } else {
+ err |= __put_user(0, &sf->fpu_save);
+ }
+ if (wsaved) {
+ __siginfo_rwin_t __user *rwp = tail;
+ tail += sizeof(*rwp);
+ err |= save_rwin_state(wsaved, rwp);
+ err |= __put_user(rwp, &sf->rwin_save);
+ } else {
+ err |= __put_user(0, &sf->rwin_save);
+ }
+
+ err |= __put_user(oldset->sig[0], &sf->info.si_mask);
+ err |= __copy_to_user(sf->extramask, &oldset->sig[1],
+ (_NSIG_WORDS - 1) * sizeof(unsigned int));
+ if (!wsaved) {
+ err |= __copy_to_user(sf, (char *) regs->u_regs[UREG_FP],
+ sizeof(struct reg_window32));
+ } else {
+ struct reg_window32 *rp;
+
+ rp = &current_thread_info()->reg_window[wsaved - 1];
+ err |= __copy_to_user(sf, rp, sizeof(struct reg_window32));
+ }
+ if (err)
+ return err;
+
+ /* 3. signal handler back-trampoline and parameters */
+ regs->u_regs[UREG_FP] = (unsigned long) sf;
+ regs->u_regs[UREG_I0] = ksig->sig;
+ regs->u_regs[UREG_I1] = (unsigned long) &sf->info;
+ regs->u_regs[UREG_I2] = (unsigned long) &sf->info;
+
+ /* 4. signal handler */
+ regs->pc = (unsigned long) ksig->ka.sa.sa_handler;
+ regs->npc = (regs->pc + 4);
+
+ /* 5. return to kernel instructions */
+ if (ksig->ka.ka_restorer)
+ regs->u_regs[UREG_I7] = (unsigned long)ksig->ka.ka_restorer;
+ else {
+ regs->u_regs[UREG_I7] = (unsigned long)(&(sf->insns[0]) - 2);
+
+ /* mov __NR_sigreturn, %g1 */
+ err |= __put_user(0x821020d8, &sf->insns[0]);
+
+ /* t 0x10 */
+ err |= __put_user(0x91d02010, &sf->insns[1]);
+ if (err)
+ return err;
+
+ /* Flush instruction space. */
+ flush_sig_insns(current->mm, (unsigned long) &(sf->insns[0]));
+ }
+ return 0;
+}
+
+static int setup_rt_frame(struct ksignal *ksig, struct pt_regs *regs,
+ sigset_t *oldset)
+{
+ struct rt_signal_frame __user *sf;
+ int sigframe_size, wsaved;
+ void __user *tail;
+ unsigned int psr;
+ int err;
+
+ synchronize_user_stack();
+ wsaved = current_thread_info()->w_saved;
+ sigframe_size = sizeof(*sf);
+ if (used_math())
+ sigframe_size += sizeof(__siginfo_fpu_t);
+ if (wsaved)
+ sigframe_size += sizeof(__siginfo_rwin_t);
+ sf = (struct rt_signal_frame __user *)
+ get_sigframe(ksig, regs, sigframe_size);
+ if (invalid_frame_pointer(sf, sigframe_size)) {
+ force_exit_sig(SIGILL);
+ return -EINVAL;
+ }
+
+ tail = sf + 1;
+ err = __put_user(regs->pc, &sf->regs.pc);
+ err |= __put_user(regs->npc, &sf->regs.npc);
+ err |= __put_user(regs->y, &sf->regs.y);
+ psr = regs->psr;
+ if (used_math())
+ psr |= PSR_EF;
+ err |= __put_user(psr, &sf->regs.psr);
+ err |= __copy_to_user(&sf->regs.u_regs, regs->u_regs, sizeof(regs->u_regs));
+ err |= __put_user(0, &sf->extra_size);
+
+ if (psr & PSR_EF) {
+ __siginfo_fpu_t __user *fp = tail;
+ tail += sizeof(*fp);
+ err |= save_fpu_state(regs, fp);
+ err |= __put_user(fp, &sf->fpu_save);
+ } else {
+ err |= __put_user(0, &sf->fpu_save);
+ }
+ if (wsaved) {
+ __siginfo_rwin_t __user *rwp = tail;
+ tail += sizeof(*rwp);
+ err |= save_rwin_state(wsaved, rwp);
+ err |= __put_user(rwp, &sf->rwin_save);
+ } else {
+ err |= __put_user(0, &sf->rwin_save);
+ }
+ err |= __copy_to_user(&sf->mask, &oldset->sig[0], sizeof(sigset_t));
+
+ /* Setup sigaltstack */
+ err |= __save_altstack(&sf->stack, regs->u_regs[UREG_FP]);
+
+ if (!wsaved) {
+ err |= __copy_to_user(sf, (char *) regs->u_regs[UREG_FP],
+ sizeof(struct reg_window32));
+ } else {
+ struct reg_window32 *rp;
+
+ rp = &current_thread_info()->reg_window[wsaved - 1];
+ err |= __copy_to_user(sf, rp, sizeof(struct reg_window32));
+ }
+
+ err |= copy_siginfo_to_user(&sf->info, &ksig->info);
+
+ if (err)
+ return err;
+
+ regs->u_regs[UREG_FP] = (unsigned long) sf;
+ regs->u_regs[UREG_I0] = ksig->sig;
+ regs->u_regs[UREG_I1] = (unsigned long) &sf->info;
+ regs->u_regs[UREG_I2] = (unsigned long) &sf->regs;
+
+ regs->pc = (unsigned long) ksig->ka.sa.sa_handler;
+ regs->npc = (regs->pc + 4);
+
+ if (ksig->ka.ka_restorer)
+ regs->u_regs[UREG_I7] = (unsigned long)ksig->ka.ka_restorer;
+ else {
+ regs->u_regs[UREG_I7] = (unsigned long)(&(sf->insns[0]) - 2);
+
+ /* mov __NR_rt_sigreturn, %g1 */
+ err |= __put_user(0x82102065, &sf->insns[0]);
+
+ /* t 0x10 */
+ err |= __put_user(0x91d02010, &sf->insns[1]);
+ if (err)
+ return err;
+
+ /* Flush instruction space. */
+ flush_sig_insns(current->mm, (unsigned long) &(sf->insns[0]));
+ }
+ return 0;
+}
+
+static inline void
+handle_signal(struct ksignal *ksig, struct pt_regs *regs)
+{
+ sigset_t *oldset = sigmask_to_save();
+ int err;
+
+ if (ksig->ka.sa.sa_flags & SA_SIGINFO)
+ err = setup_rt_frame(ksig, regs, oldset);
+ else
+ err = setup_frame(ksig, regs, oldset);
+ signal_setup_done(err, ksig, 0);
+}
+
+static inline void syscall_restart(unsigned long orig_i0, struct pt_regs *regs,
+ struct sigaction *sa)
+{
+ switch(regs->u_regs[UREG_I0]) {
+ case ERESTART_RESTARTBLOCK:
+ case ERESTARTNOHAND:
+ no_system_call_restart:
+ regs->u_regs[UREG_I0] = EINTR;
+ regs->psr |= PSR_C;
+ break;
+ case ERESTARTSYS:
+ if (!(sa->sa_flags & SA_RESTART))
+ goto no_system_call_restart;
+ fallthrough;
+ case ERESTARTNOINTR:
+ regs->u_regs[UREG_I0] = orig_i0;
+ regs->pc -= 4;
+ regs->npc -= 4;
+ }
+}
+
+/* Note that 'init' is a special process: it doesn't get signals it doesn't
+ * want to handle. Thus you cannot kill init even with a SIGKILL even by
+ * mistake.
+ */
+static void do_signal(struct pt_regs *regs, unsigned long orig_i0)
+{
+ struct ksignal ksig;
+ int restart_syscall;
+ bool has_handler;
+
+ /* It's a lot of work and synchronization to add a new ptrace
+ * register for GDB to save and restore in order to get
+ * orig_i0 correct for syscall restarts when debugging.
+ *
+ * Although it should be the case that most of the global
+ * registers are volatile across a system call, glibc already
+ * depends upon that fact that we preserve them. So we can't
+ * just use any global register to save away the orig_i0 value.
+ *
+ * In particular %g2, %g3, %g4, and %g5 are all assumed to be
+ * preserved across a system call trap by various pieces of
+ * code in glibc.
+ *
+ * %g7 is used as the "thread register". %g6 is not used in
+ * any fixed manner. %g6 is used as a scratch register and
+ * a compiler temporary, but it's value is never used across
+ * a system call. Therefore %g6 is usable for orig_i0 storage.
+ */
+ if (pt_regs_is_syscall(regs) && (regs->psr & PSR_C))
+ regs->u_regs[UREG_G6] = orig_i0;
+
+ has_handler = get_signal(&ksig);
+
+ /* If the debugger messes with the program counter, it clears
+ * the software "in syscall" bit, directing us to not perform
+ * a syscall restart.
+ */
+ restart_syscall = 0;
+ if (pt_regs_is_syscall(regs) && (regs->psr & PSR_C)) {
+ restart_syscall = 1;
+ orig_i0 = regs->u_regs[UREG_G6];
+ }
+
+ if (has_handler) {
+ if (restart_syscall)
+ syscall_restart(orig_i0, regs, &ksig.ka.sa);
+ handle_signal(&ksig, regs);
+ } else {
+ if (restart_syscall) {
+ switch (regs->u_regs[UREG_I0]) {
+ case ERESTARTNOHAND:
+ case ERESTARTSYS:
+ case ERESTARTNOINTR:
+ /* replay the system call when we are done */
+ regs->u_regs[UREG_I0] = orig_i0;
+ regs->pc -= 4;
+ regs->npc -= 4;
+ pt_regs_clear_syscall(regs);
+ fallthrough;
+ case ERESTART_RESTARTBLOCK:
+ regs->u_regs[UREG_G1] = __NR_restart_syscall;
+ regs->pc -= 4;
+ regs->npc -= 4;
+ pt_regs_clear_syscall(regs);
+ }
+ }
+ restore_saved_sigmask();
+ }
+}
+
+void do_notify_resume(struct pt_regs *regs, unsigned long orig_i0,
+ unsigned long thread_info_flags)
+{
+ if (thread_info_flags & (_TIF_SIGPENDING | _TIF_NOTIFY_SIGNAL))
+ do_signal(regs, orig_i0);
+ if (thread_info_flags & _TIF_NOTIFY_RESUME)
+ resume_user_mode_work(regs);
+}
+
+asmlinkage int do_sys_sigstack(struct sigstack __user *ssptr,
+ struct sigstack __user *ossptr,
+ unsigned long sp)
+{
+ int ret = -EFAULT;
+
+ /* First see if old state is wanted. */
+ if (ossptr) {
+ if (put_user(current->sas_ss_sp + current->sas_ss_size,
+ &ossptr->the_stack) ||
+ __put_user(on_sig_stack(sp), &ossptr->cur_status))
+ goto out;
+ }
+
+ /* Now see if we want to update the new state. */
+ if (ssptr) {
+ char *ss_sp;
+
+ if (get_user(ss_sp, &ssptr->the_stack))
+ goto out;
+ /* If the current stack was set with sigaltstack, don't
+ swap stacks while we are on it. */
+ ret = -EPERM;
+ if (current->sas_ss_sp && on_sig_stack(sp))
+ goto out;
+
+ /* Since we don't know the extent of the stack, and we don't
+ track onstack-ness, but rather calculate it, we must
+ presume a size. Ho hum this interface is lossy. */
+ current->sas_ss_sp = (unsigned long)ss_sp - SIGSTKSZ;
+ current->sas_ss_size = SIGSTKSZ;
+ }
+ ret = 0;
+out:
+ return ret;
+}
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