x86: get rid of get_user_ex() in ia32_restore_sigcontext() (978727ca) · Commits · 戴 / test

arch/x86/ia32/ia32_signal.c

+44 −62

Original line number	Diff line number	Diff line
		@@ -36,85 +36,65 @@
		#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.
		*/
		#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 = (seg) \| 3; \
		unsigned int cur = get_user_seg(seg); \
		if (pre != cur) \
		set_user_seg(seg, pre); \
		}

		static int ia32_restore_sigcontext(struct pt_regs *regs,
		struct sigcontext_32 __user *sc)
		struct sigcontext_32 __user *usc)
		{
		unsigned int tmpflags, err = 0;
		u16 gs, fs, es, ds;
		void __user *buf;
		u32 tmp;
		struct sigcontext_32 sc;

		/* Always make any pending restarted system calls return -EINTR */
		current->restart_block.fn = do_no_restart_syscall;

		get_user_try {
		gs = GET_SEG(gs);
		fs = GET_SEG(fs);
		ds = GET_SEG(ds);
		es = GET_SEG(es);

		COPY(di); COPY(si); COPY(bp); COPY(sp); COPY(bx);
		COPY(dx); COPY(cx); COPY(ip); COPY(ax);
		/* Don't touch extended registers */

		COPY_SEG_CPL3(cs);
		COPY_SEG_CPL3(ss);
		if (unlikely(copy_from_user(&sc, usc, sizeof(sc))))
		return -EFAULT;

		get_user_ex(tmpflags, &sc->flags);
		regs->flags = (regs->flags & ~FIX_EFLAGS) \| (tmpflags & FIX_EFLAGS);
		/* 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;

		get_user_ex(tmp, &sc->fpstate);
		buf = compat_ptr(tmp);
		} get_user_catch(err);

		/*
		* 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);

		err \|= fpu__restore_sig(buf, 1);

		return err;
		reload_segments(&sc);
		return fpu__restore_sig(compat_ptr(sc.fpstate), 1);
		}

		COMPAT_SYSCALL_DEFINE0(sigreturn)
		@@ -172,6 +152,8 @@ badframe:
		* Set up a signal frame.
		*/

		#define get_user_seg(seg) ({ unsigned int v; savesegment(seg, v); v; })

		static int ia32_setup_sigcontext(struct sigcontext_32 __user *sc,
		void __user *fpstate,
		struct pt_regs *regs, unsigned int mask)

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