Adding upstream version 4.19.249.upstream/4.19.249upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 568 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..5665261ce
--- /dev/null
+++ b/arch/sparc/kernel/signal_32.c
@@ -0,0 +1,568 @@
+// 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/tracehook.h>
+
+#include <linux/uaccess.h>
+#include <asm/ptrace.h>
+#include <asm/pgalloc.h>
+#include <asm/pgtable.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((unsigned long)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, current);
+}
+
+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, current);
+}
+
+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)) {
+		do_exit(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)) {
+		do_exit(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_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 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);
+			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)
+		do_signal(regs, orig_i0);
+	if (thread_info_flags & _TIF_NOTIFY_RESUME) {
+		clear_thread_flag(TIF_NOTIFY_RESUME);
+		tracehook_notify_resume(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;
+}