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Diffstat (limited to 'arch/x86/ia32/ia32_signal.c')
-rw-r--r--arch/x86/ia32/ia32_signal.c304
1 files changed, 137 insertions, 167 deletions
diff --git a/arch/x86/ia32/ia32_signal.c b/arch/x86/ia32/ia32_signal.c
index a3aefe9b9401..f9d8804144d0 100644
--- a/arch/x86/ia32/ia32_signal.c
+++ b/arch/x86/ia32/ia32_signal.c
@@ -36,70 +36,56 @@
#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);
-
- get_user_ex(tmpflags, &sc->flags);
- regs->flags = (regs->flags & ~FIX_EFLAGS) | (tmpflags & FIX_EFLAGS);
- /* disable syscall checks */
- regs->orig_ax = -1;
+ if (unlikely(copy_from_user(&sc, usc, sizeof(sc))))
+ return -EFAULT;
- get_user_ex(tmp, &sc->fpstate);
- buf = compat_ptr(tmp);
- } get_user_catch(err);
+ /* 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
@@ -107,14 +93,8 @@ static int ia32_restore_sigcontext(struct pt_regs *regs,
* 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)
@@ -126,10 +106,7 @@ COMPAT_SYSCALL_DEFINE0(sigreturn)
if (!access_ok(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))))
+ || __get_user(((__u32 *)&set)[1], &frame->extramask[0]))
goto badframe;
set_current_blocked(&set);
@@ -153,7 +130,7 @@ COMPAT_SYSCALL_DEFINE0(rt_sigreturn)
if (!access_ok(frame, sizeof(*frame)))
goto badframe;
- if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
+ if (__get_user(set.sig[0], (__u64 __user *)&frame->uc.uc_sigmask))
goto badframe;
set_current_blocked(&set);
@@ -175,44 +152,51 @@ badframe:
* Set up a signal frame.
*/
-static int ia32_setup_sigcontext(struct sigcontext_32 __user *sc,
- void __user *fpstate,
- struct pt_regs *regs, unsigned int mask)
+#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)
{
- int err = 0;
-
- put_user_try {
- put_user_ex(get_user_seg(gs), (unsigned int __user *)&sc->gs);
- put_user_ex(get_user_seg(fs), (unsigned int __user *)&sc->fs);
- put_user_ex(get_user_seg(ds), (unsigned int __user *)&sc->ds);
- put_user_ex(get_user_seg(es), (unsigned int __user *)&sc->es);
-
- put_user_ex(regs->di, &sc->di);
- put_user_ex(regs->si, &sc->si);
- put_user_ex(regs->bp, &sc->bp);
- put_user_ex(regs->sp, &sc->sp);
- put_user_ex(regs->bx, &sc->bx);
- put_user_ex(regs->dx, &sc->dx);
- put_user_ex(regs->cx, &sc->cx);
- put_user_ex(regs->ax, &sc->ax);
- put_user_ex(current->thread.trap_nr, &sc->trapno);
- put_user_ex(current->thread.error_code, &sc->err);
- put_user_ex(regs->ip, &sc->ip);
- put_user_ex(regs->cs, (unsigned int __user *)&sc->cs);
- put_user_ex(regs->flags, &sc->flags);
- put_user_ex(regs->sp, &sc->sp_at_signal);
- put_user_ex(regs->ss, (unsigned int __user *)&sc->ss);
-
- put_user_ex(ptr_to_compat(fpstate), &sc->fpstate);
-
- /* non-iBCS2 extensions.. */
- put_user_ex(mask, &sc->oldmask);
- put_user_ex(current->thread.cr2, &sc->cr2);
- } put_user_catch(err);
-
- return err;
+ 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)
+
/*
* Determine which stack to use..
*/
@@ -252,8 +236,7 @@ int ia32_setup_frame(int sig, struct ksignal *ksig,
{
struct sigframe_ia32 __user *frame;
void __user *restorer;
- int err = 0;
- void __user *fpstate = NULL;
+ void __user *fp = NULL;
/* copy_to_user optimizes that into a single 8 byte store */
static const struct {
@@ -266,22 +249,7 @@ int ia32_setup_frame(int sig, struct ksignal *ksig,
0x80cd, /* int $0x80 */
};
- frame = get_sigframe(ksig, regs, sizeof(*frame), &fpstate);
-
- if (!access_ok(frame, sizeof(*frame)))
- return -EFAULT;
-
- if (__put_user(sig, &frame->sig))
- return -EFAULT;
-
- if (ia32_setup_sigcontext(&frame->sc, fpstate, regs, set->sig[0]))
- return -EFAULT;
-
- if (_COMPAT_NSIG_WORDS > 1) {
- if (__copy_to_user(frame->extramask, &set->sig[1],
- sizeof(frame->extramask)))
- return -EFAULT;
- }
+ frame = get_sigframe(ksig, regs, sizeof(*frame), &fp);
if (ksig->ka.sa.sa_flags & SA_RESTORER) {
restorer = ksig->ka.sa.sa_restorer;
@@ -294,19 +262,20 @@ int ia32_setup_frame(int sig, struct ksignal *ksig,
restorer = &frame->retcode;
}
- put_user_try {
- put_user_ex(ptr_to_compat(restorer), &frame->pretcode);
-
- /*
- * These are actually not used anymore, but left because some
- * gdb versions depend on them as a marker.
- */
- put_user_ex(*((u64 *)&code), (u64 __user *)frame->retcode);
- } put_user_catch(err);
-
- if (err)
+ if (!user_access_begin(frame, sizeof(*frame)))
return -EFAULT;
+ unsafe_put_user(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;
@@ -323,6 +292,9 @@ int ia32_setup_frame(int sig, struct ksignal *ksig,
regs->ss = __USER32_DS;
return 0;
+Efault:
+ user_access_end();
+ return -EFAULT;
}
int ia32_setup_rt_frame(int sig, struct ksignal *ksig,
@@ -330,10 +302,9 @@ int ia32_setup_rt_frame(int sig, struct ksignal *ksig,
{
struct rt_sigframe_ia32 __user *frame;
void __user *restorer;
- int err = 0;
- void __user *fpstate = NULL;
+ void __user *fp = NULL;
- /* __copy_to_user optimizes that into a single 8 byte store */
+ /* unsafe_put_user optimizes that into a single 8 byte store */
static const struct {
u8 movl;
u32 val;
@@ -346,44 +317,40 @@ int ia32_setup_rt_frame(int sig, struct ksignal *ksig,
0,
};
- frame = get_sigframe(ksig, regs, sizeof(*frame), &fpstate);
+ frame = get_sigframe(ksig, regs, sizeof(*frame), &fp);
- if (!access_ok(frame, sizeof(*frame)))
+ if (!user_access_begin(frame, sizeof(*frame)))
return -EFAULT;
- put_user_try {
- put_user_ex(sig, &frame->sig);
- put_user_ex(ptr_to_compat(&frame->info), &frame->pinfo);
- put_user_ex(ptr_to_compat(&frame->uc), &frame->puc);
+ unsafe_put_user(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))
- put_user_ex(UC_FP_XSTATE, &frame->uc.uc_flags);
- else
- put_user_ex(0, &frame->uc.uc_flags);
- put_user_ex(0, &frame->uc.uc_link);
- compat_save_altstack_ex(&frame->uc.uc_stack, regs->sp);
+ /* 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;
- put_user_ex(ptr_to_compat(restorer), &frame->pretcode);
-
- /*
- * Not actually used anymore, but left because some gdb
- * versions need it.
- */
- put_user_ex(*((u64 *)&code), (u64 __user *)frame->retcode);
- } put_user_catch(err);
-
- err |= __copy_siginfo_to_user32(&frame->info, &ksig->info, false);
- err |= ia32_setup_sigcontext(&frame->uc.uc_mcontext, fpstate,
- regs, set->sig[0]);
- err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
-
- if (err)
+ 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 *)&frame->uc.uc_sigmask, Efault);
+ user_access_end();
+
+ if (__copy_siginfo_to_user32(&frame->info, &ksig->info, false))
return -EFAULT;
/* Set up registers for signal handler */
@@ -402,4 +369,7 @@ int ia32_setup_rt_frame(int sig, struct ksignal *ksig,
regs->ss = __USER32_DS;
return 0;
+Efault:
+ user_access_end();
+ return -EFAULT;
}