[PATCH] uml: S390 preparation, abstract host page fault data
This patch removes the arch-specific fault/trap-infos from thread and
skas-regs.
It adds a new struct faultinfo, that is arch-specific defined in
sysdep/faultinfo.h.
The structure is inserted in thread.arch and thread.regs.skas and
thread.regs.tt
Now, segv and other trap-handlers can copy the contents from regs.X.faultinfo
to thread.arch.faultinfo with one simple assignment.
Also, the number of macros necessary is reduced to
FAULT_ADDRESS(struct faultinfo)
extracts the faulting address from faultinfo
FAULT_WRITE(struct faultinfo)
extracts the "is_write" flag
SEGV_IS_FIXABLE(struct faultinfo)
is true for the fixable segvs, i.e. (TRAP == 14)
on i386
UPT_FAULTINFO(regs)
result is (struct faultinfo *) to the faultinfo
in regs->skas.faultinfo
GET_FAULTINFO_FROM_SC(struct faultinfo, struct sigcontext *)
copies the relevant parts of the sigcontext to
struct faultinfo.
On SIGSEGV, call user_signal() instead of handle_segv(), if the architecture
provides the information needed in PTRACE_FAULTINFO, or if PTRACE_FAULTINFO is
missing, because segv-stub will provide the info.
The benefit of the change is, that in case of a non-fixable SIGSEGV, we can
give user processes a SIGSEGV, instead of possibly looping on pagefault
handling.
Since handle_segv() sikked arch_fixup() implicitly by passing ip==0 to segv(),
I changed segv() to call arch_fixup() only, if !is_user.
Signed-off-by: Bodo Stroesser <bstroesser@fujitsu-siemens.com>
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/arch/um/kernel/ptrace.c b/arch/um/kernel/ptrace.c
index ffc599b..ec19fed 100644
--- a/arch/um/kernel/ptrace.c
+++ b/arch/um/kernel/ptrace.c
@@ -252,13 +252,13 @@
break;
#endif
case PTRACE_FAULTINFO: {
- struct ptrace_faultinfo fault;
-
- fault = ((struct ptrace_faultinfo)
- { .is_write = child->thread.err,
- .addr = child->thread.cr2 });
- ret = copy_to_user((unsigned long __user *) data, &fault,
- sizeof(fault));
+ /* Take the info from thread->arch->faultinfo,
+ * but transfer max. sizeof(struct ptrace_faultinfo).
+ * On i386, ptrace_faultinfo is smaller!
+ */
+ ret = copy_to_user((unsigned long __user *) data,
+ &child->thread.arch.faultinfo,
+ sizeof(struct ptrace_faultinfo));
if(ret)
break;
break;
@@ -269,6 +269,7 @@
sizeof(child->pending.signal));
break;
+#ifdef PTRACE_LDT
case PTRACE_LDT: {
struct ptrace_ldt ldt;
@@ -284,6 +285,7 @@
ret = -EIO;
break;
}
+#endif
#ifdef CONFIG_PROC_MM
case PTRACE_SWITCH_MM: {
struct mm_struct *old = child->mm;