x86/signal/32: Merge native and compat 32-bit signal code

There are significant differences between signal handling on 32-bit vs.
64-bit, like different structure layouts and legacy syscalls.  Instead
of duplicating that code for native and compat, merge both versions
into one file.

Signed-off-by: Brian Gerst <brgerst@gmail.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
Link: https://lore.kernel.org/r/20220606203802.158958-8-brgerst@gmail.com
Signed-off-by: Borislav Petkov <bp@suse.de>

2 files changed, 0 insertions, 342 deletions

diff --git a/arch/x86/ia32/Makefile b/arch/x86/ia32/Makefile
index e481056698de..333556a86b2a 100644
--- a/arch/x86/ia32/Makefile
+++ b/arch/x86/ia32/Makefile
@@ -3,7 +3,5 @@
 # Makefile for the ia32 kernel emulation subsystem.
 #
 
-obj-$(CONFIG_IA32_EMULATION) := ia32_signal.o
-
 audit-class-$(CONFIG_AUDIT) := audit.o
 obj-$(CONFIG_IA32_EMULATION) += $(audit-class-y)
diff --git a/arch/x86/ia32/ia32_signal.c b/arch/x86/ia32/ia32_signal.c
deleted file mode 100644
index e28421f53d44..000000000000
--- a/arch/x86/ia32/ia32_signal.c
+++ /dev/null
@@ -1,340 +0,0 @@
-// 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 <linux/syscalls.h>
-#include <asm/ucontext.h>
-#include <linux/uaccess.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>
-
-static inline void reload_segments(struct sigcontext_32 *sc)
-{
-	unsigned int cur;
-
-	savesegment(gs, cur);
-	if ((sc->gs | 0x03) != cur)
-		load_gs_index(sc->gs | 0x03);
-	savesegment(fs, cur);
-	if ((sc->fs | 0x03) != cur)
-		loadsegment(fs, sc->fs | 0x03);
-	savesegment(ds, cur);
-	if ((sc->ds | 0x03) != cur)
-		loadsegment(ds, sc->ds | 0x03);
-	savesegment(es, cur);
-	if ((sc->es | 0x03) != cur)
-		loadsegment(es, sc->es | 0x03);
-}
-
-/*
- * Do a signal return; undo the signal stack.
- */
-static bool ia32_restore_sigcontext(struct pt_regs *regs,
-				    struct sigcontext_32 __user *usc)
-{
-	struct sigcontext_32 sc;
-
-	/* Always make any pending restarted system calls return -EINTR */
-	current->restart_block.fn = do_no_restart_syscall;
-
-	if (unlikely(copy_from_user(&sc, usc, sizeof(sc))))
-		return false;
-
-	/* Get only the ia32 registers. */
-	regs->bx = sc.bx;
-	regs->cx = sc.cx;
-	regs->dx = sc.dx;
-	regs->si = sc.si;
-	regs->di = sc.di;
-	regs->bp = sc.bp;
-	regs->ax = sc.ax;
-	regs->sp = sc.sp;
-	regs->ip = sc.ip;
-
-	/* Get CS/SS and force CPL3 */
-	regs->cs = sc.cs | 0x03;
-	regs->ss = sc.ss | 0x03;
-
-	regs->flags = (regs->flags & ~FIX_EFLAGS) | (sc.flags & FIX_EFLAGS);
-	/* disable syscall checks */
-	regs->orig_ax = -1;
-
-	/*
-	 * 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_segments(&sc);
-	return fpu__restore_sig(compat_ptr(sc.fpstate), 1);
-}
-
-COMPAT_SYSCALL_DEFINE0(sigreturn)
-{
-	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(frame, sizeof(*frame)))
-		goto badframe;
-	if (__get_user(set.sig[0], &frame->sc.oldmask)
-	    || __get_user(((__u32 *)&set)[1], &frame->extramask[0]))
-		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;
-}
-
-COMPAT_SYSCALL_DEFINE0(rt_sigreturn)
-{
-	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(frame, sizeof(*frame)))
-		goto badframe;
-	if (__get_user(set.sig[0], (__u64 __user *)&frame->uc.uc_sigmask))
-		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.
- */
-
-#define get_user_seg(seg)	({ unsigned int v; savesegment(seg, v); v; })
-
-static __always_inline int
-__unsafe_setup_sigcontext32(struct sigcontext_32 __user *sc,
-			    void __user *fpstate,
-			    struct pt_regs *regs, unsigned int mask)
-{
-	unsafe_put_user(get_user_seg(gs), (unsigned int __user *)&sc->gs, Efault);
-	unsafe_put_user(get_user_seg(fs), (unsigned int __user *)&sc->fs, Efault);
-	unsafe_put_user(get_user_seg(ds), (unsigned int __user *)&sc->ds, Efault);
-	unsafe_put_user(get_user_seg(es), (unsigned int __user *)&sc->es, Efault);
-
-	unsafe_put_user(regs->di, &sc->di, Efault);
-	unsafe_put_user(regs->si, &sc->si, Efault);
-	unsafe_put_user(regs->bp, &sc->bp, Efault);
-	unsafe_put_user(regs->sp, &sc->sp, Efault);
-	unsafe_put_user(regs->bx, &sc->bx, Efault);
-	unsafe_put_user(regs->dx, &sc->dx, Efault);
-	unsafe_put_user(regs->cx, &sc->cx, Efault);
-	unsafe_put_user(regs->ax, &sc->ax, Efault);
-	unsafe_put_user(current->thread.trap_nr, &sc->trapno, Efault);
-	unsafe_put_user(current->thread.error_code, &sc->err, Efault);
-	unsafe_put_user(regs->ip, &sc->ip, Efault);
-	unsafe_put_user(regs->cs, (unsigned int __user *)&sc->cs, Efault);
-	unsafe_put_user(regs->flags, &sc->flags, Efault);
-	unsafe_put_user(regs->sp, &sc->sp_at_signal, Efault);
-	unsafe_put_user(regs->ss, (unsigned int __user *)&sc->ss, Efault);
-
-	unsafe_put_user(ptr_to_compat(fpstate), &sc->fpstate, Efault);
-
-	/* non-iBCS2 extensions.. */
-	unsafe_put_user(mask, &sc->oldmask, Efault);
-	unsafe_put_user(current->thread.cr2, &sc->cr2, Efault);
-	return 0;
-
-Efault:
-	return -EFAULT;
-}
-
-#define unsafe_put_sigcontext32(sc, fp, regs, set, label)		\
-do {									\
-	if (__unsafe_setup_sigcontext32(sc, fp, regs, set->sig[0]))	\
-		goto label;						\
-} while(0)
-
-int ia32_setup_frame(struct ksignal *ksig, struct pt_regs *regs)
-{
-	compat_sigset_t *set = (compat_sigset_t *) sigmask_to_save();
-	struct sigframe_ia32 __user *frame;
-	void __user *restorer;
-	void __user *fp = 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), &fp);
-
-	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;
-	}
-
-	if (!user_access_begin(frame, sizeof(*frame)))
-		return -EFAULT;
-
-	unsafe_put_user(ksig->sig, &frame->sig, Efault);
-	unsafe_put_sigcontext32(&frame->sc, fp, regs, set, Efault);
-	unsafe_put_user(set->sig[1], &frame->extramask[0], Efault);
-	unsafe_put_user(ptr_to_compat(restorer), &frame->pretcode, Efault);
-	/*
-	 * These are actually not used anymore, but left because some
-	 * gdb versions depend on them as a marker.
-	 */
-	unsafe_put_user(*((u64 *)&code), (u64 __user *)frame->retcode, Efault);
-	user_access_end();
-
-	/* 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 = ksig->sig;
-	regs->dx = 0;
-	regs->cx = 0;
-
-	loadsegment(ds, __USER_DS);
-	loadsegment(es, __USER_DS);
-
-	regs->cs = __USER32_CS;
-	regs->ss = __USER_DS;
-
-	return 0;
-Efault:
-	user_access_end();
-	return -EFAULT;
-}
-
-int ia32_setup_rt_frame(struct ksignal *ksig, struct pt_regs *regs)
-{
-	compat_sigset_t *set = (compat_sigset_t *) sigmask_to_save();
-	struct rt_sigframe_ia32 __user *frame;
-	void __user *restorer;
-	void __user *fp = NULL;
-
-	/* unsafe_put_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), &fp);
-
-	if (!user_access_begin(frame, sizeof(*frame)))
-		return -EFAULT;
-
-	unsafe_put_user(ksig->sig, &frame->sig, Efault);
-	unsafe_put_user(ptr_to_compat(&frame->info), &frame->pinfo, Efault);
-	unsafe_put_user(ptr_to_compat(&frame->uc), &frame->puc, Efault);
-
-	/* Create the ucontext.  */
-	if (static_cpu_has(X86_FEATURE_XSAVE))
-		unsafe_put_user(UC_FP_XSTATE, &frame->uc.uc_flags, Efault);
-	else
-		unsafe_put_user(0, &frame->uc.uc_flags, Efault);
-	unsafe_put_user(0, &frame->uc.uc_link, Efault);
-	unsafe_compat_save_altstack(&frame->uc.uc_stack, regs->sp, Efault);
-
-	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;
-	unsafe_put_user(ptr_to_compat(restorer), &frame->pretcode, Efault);
-
-	/*
-	 * Not actually used anymore, but left because some gdb
-	 * versions need it.
-	 */
-	unsafe_put_user(*((u64 *)&code), (u64 __user *)frame->retcode, Efault);
-	unsafe_put_sigcontext32(&frame->uc.uc_mcontext, fp, regs, set, Efault);
-	unsafe_put_user(*(__u64 *)set, (__u64 __user *)&frame->uc.uc_sigmask, Efault);
-	user_access_end();
-
-	if (__copy_siginfo_to_user32(&frame->info, &ksig->info))
-		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 = ksig->sig;
-	regs->dx = (unsigned long) &frame->info;
-	regs->cx = (unsigned long) &frame->uc;
-
-	loadsegment(ds, __USER_DS);
-	loadsegment(es, __USER_DS);
-
-	regs->cs = __USER32_CS;
-	regs->ss = __USER_DS;
-
-	return 0;
-Efault:
-	user_access_end();
-	return -EFAULT;
-}