ENTRY(sys_sigreturn)
SAVE_SWITCH_STACK
- movel %sp,%sp@- | switch_stack pointer
- pea %sp@(SWITCH_STACK_SIZE+4) | pt_regs pointer
+ movel %sp,%a1 | switch_stack pointer
+ lea %sp@(SWITCH_STACK_SIZE),%a0 | pt_regs pointer
+ lea %sp@(-84),%sp | leave a gap
+ movel %a1,%sp@-
+ movel %a0,%sp@-
jbsr do_sigreturn
- addql #8,%sp
- RESTORE_SWITCH_STACK
- rts
+ jra 1f | shared with rt_sigreturn()
ENTRY(sys_rt_sigreturn)
SAVE_SWITCH_STACK
- movel %sp,%sp@- | switch_stack pointer
- pea %sp@(SWITCH_STACK_SIZE+4) | pt_regs pointer
+ movel %sp,%a1 | switch_stack pointer
+ lea %sp@(SWITCH_STACK_SIZE),%a0 | pt_regs pointer
+ lea %sp@(-84),%sp | leave a gap
+ movel %a1,%sp@-
+ movel %a0,%sp@-
+ | stack contents:
+ | [original pt_regs address] [original switch_stack address]
+ | [gap] [switch_stack] [pt_regs] [exception frame]
jbsr do_rt_sigreturn
- addql #8,%sp
+
+1:
+ | stack contents now:
+ | [original pt_regs address] [original switch_stack address]
+ | [unused part of the gap] [moved switch_stack] [moved pt_regs]
+ | [replacement exception frame]
+ | return value of do_{rt_,}sigreturn() points to moved switch_stack.
+
+ movel %d0,%sp | discard the leftover junk
RESTORE_SWITCH_STACK
+ | stack contents now is just [syscall return address] [pt_regs] [frame]
+ | return pt_regs.d0
+ movel %sp@(PT_OFF_D0+4),%d0
rts
ENTRY(buserr)
addql #4,%sp
jra .Lret_from_exception
-ENTRY(ret_from_signal)
- movel %curptr@(TASK_STACK),%a1
- tstb %a1@(TINFO_FLAGS+2)
- jge 1f
- lea %sp@(SWITCH_STACK_SIZE),%a1
- movel %a1,%curptr@(TASK_THREAD+THREAD_ESP0)
- jbsr syscall_trace
-1: RESTORE_SWITCH_STACK
- addql #4,%sp
-/* on 68040 complete pending writebacks if any */
-#ifdef CONFIG_M68040
- bfextu %sp@(PT_OFF_FORMATVEC){#0,#4},%d0
- subql #7,%d0 | bus error frame ?
- jbne 1f
- movel %sp,%sp@-
- jbsr berr_040cleanup
- addql #4,%sp
-1:
-#endif
- jra .Lret_from_exception
-
ENTRY(system_call)
SAVE_ALL_SYS
static int mangle_kernel_stack(struct pt_regs *regs, int formatvec,
void __user *fp)
{
- int fsize = frame_extra_sizes(formatvec >> 12);
- if (fsize < 0) {
+ int extra = frame_extra_sizes(formatvec >> 12);
+ char buf[sizeof_field(struct frame, un)];
+
+ if (extra < 0) {
/*
* user process trying to return with weird frame format
*/
pr_debug("user process returning with weird frame format\n");
- return 1;
+ return -1;
}
- if (!fsize) {
- regs->format = formatvec >> 12;
- regs->vector = formatvec & 0xfff;
- } else {
- struct switch_stack *sw = (struct switch_stack *)regs - 1;
- /* yes, twice as much as max(sizeof(frame.un.fmt<x>)) */
- unsigned long buf[sizeof_field(struct frame, un) / 2];
-
- /* that'll make sure that expansion won't crap over data */
- if (copy_from_user(buf + fsize / 4, fp, fsize))
- return 1;
-
- /* point of no return */
- regs->format = formatvec >> 12;
- regs->vector = formatvec & 0xfff;
-#define frame_offset (sizeof(struct pt_regs)+sizeof(struct switch_stack))
- __asm__ __volatile__ (
-#ifdef CONFIG_COLDFIRE
- " movel %0,%/sp\n\t"
- " bra ret_from_signal\n"
-#else
- " movel %0,%/a0\n\t"
- " subl %1,%/a0\n\t" /* make room on stack */
- " movel %/a0,%/sp\n\t" /* set stack pointer */
- /* move switch_stack and pt_regs */
- "1: movel %0@+,%/a0@+\n\t"
- " dbra %2,1b\n\t"
- " lea %/sp@(%c3),%/a0\n\t" /* add offset of fmt */
- " lsrl #2,%1\n\t"
- " subql #1,%1\n\t"
- /* copy to the gap we'd made */
- "2: movel %4@+,%/a0@+\n\t"
- " dbra %1,2b\n\t"
- " bral ret_from_signal\n"
+ if (extra && copy_from_user(buf, fp, extra))
+ return -1;
+ regs->format = formatvec >> 12;
+ regs->vector = formatvec & 0xfff;
+ if (extra) {
+ void *p = (struct switch_stack *)regs - 1;
+ struct frame *new = (void *)regs - extra;
+ int size = sizeof(struct pt_regs)+sizeof(struct switch_stack);
+
+ memmove(p - extra, p, size);
+ memcpy(p - extra + size, buf, extra);
+ current->thread.esp0 = (unsigned long)&new->ptregs;
+#ifdef CONFIG_M68040
+ /* on 68040 complete pending writebacks if any */
+ if (new->ptregs.format == 7) // bus error frame
+ berr_040cleanup(new);
#endif
- : /* no outputs, it doesn't ever return */
- : "a" (sw), "d" (fsize), "d" (frame_offset/4-1),
- "n" (frame_offset), "a" (buf + fsize/4)
- : "a0");
-#undef frame_offset
}
- return 0;
+ return extra;
}
static inline int
{
int formatvec;
struct sigcontext context;
- int err = 0;
siginfo_build_tests();
/* get previous context */
if (copy_from_user(&context, usc, sizeof(context)))
- goto badframe;
+ return -1;
/* restore passed registers */
regs->d0 = context.sc_d0;
wrusp(context.sc_usp);
formatvec = context.sc_formatvec;
- err = restore_fpu_state(&context);
-
- if (err || mangle_kernel_stack(regs, formatvec, fp))
- goto badframe;
-
- return 0;
+ if (restore_fpu_state(&context))
+ return -1;
-badframe:
- return 1;
+ return mangle_kernel_stack(regs, formatvec, fp);
}
static inline int
err = __get_user(temp, &uc->uc_mcontext.version);
if (temp != MCONTEXT_VERSION)
- goto badframe;
+ return -1;
/* restore passed registers */
err |= __get_user(regs->d0, &gregs[0]);
err |= __get_user(regs->d1, &gregs[1]);
err |= restore_altstack(&uc->uc_stack);
if (err)
- goto badframe;
-
- if (mangle_kernel_stack(regs, temp, &uc->uc_extra))
- goto badframe;
+ return -1;
- return 0;
-
-badframe:
- return 1;
+ return mangle_kernel_stack(regs, temp, &uc->uc_extra);
}
-asmlinkage int do_sigreturn(struct pt_regs *regs, struct switch_stack *sw)
+asmlinkage void *do_sigreturn(struct pt_regs *regs, struct switch_stack *sw)
{
unsigned long usp = rdusp();
struct sigframe __user *frame = (struct sigframe __user *)(usp - 4);
sigset_t set;
+ int size;
if (!access_ok(frame, sizeof(*frame)))
goto badframe;
set_current_blocked(&set);
- if (restore_sigcontext(regs, &frame->sc, frame + 1))
+ size = restore_sigcontext(regs, &frame->sc, frame + 1);
+ if (size < 0)
goto badframe;
- return regs->d0;
+ return (void *)sw - size;
badframe:
force_sig(SIGSEGV);
- return 0;
+ return sw;
}
-asmlinkage int do_rt_sigreturn(struct pt_regs *regs, struct switch_stack *sw)
+asmlinkage void *do_rt_sigreturn(struct pt_regs *regs, struct switch_stack *sw)
{
unsigned long usp = rdusp();
struct rt_sigframe __user *frame = (struct rt_sigframe __user *)(usp - 4);
sigset_t set;
+ int size;
if (!access_ok(frame, sizeof(*frame)))
goto badframe;
set_current_blocked(&set);
- if (rt_restore_ucontext(regs, sw, &frame->uc))
+ size = rt_restore_ucontext(regs, sw, &frame->uc);
+ if (size < 0)
goto badframe;
- return regs->d0;
+ return (void *)sw - size;
badframe:
force_sig(SIGSEGV);
- return 0;
+ return sw;
}
static inline struct pt_regs *rte_regs(struct pt_regs *regs)
projects / kernel.git / commitdiff