[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/skas/include/skas.h b/arch/um/kernel/skas/include/skas.h
index f0702c2..96b51db 100644
--- a/arch/um/kernel/skas/include/skas.h
+++ b/arch/um/kernel/skas/include/skas.h
@@ -27,9 +27,10 @@
extern int unmap(int fd, void *addr, unsigned long len);
extern int protect(int fd, unsigned long addr, unsigned long len,
int r, int w, int x);
-extern void user_signal(int sig, union uml_pt_regs *regs);
+extern void user_signal(int sig, union uml_pt_regs *regs, int pid);
extern int new_mm(int from);
extern void start_userspace(int cpu);
+extern void get_skas_faultinfo(int pid, struct faultinfo * fi);
extern long execute_syscall_skas(void *r);
#endif
diff --git a/arch/um/kernel/skas/process.c b/arch/um/kernel/skas/process.c
index b4ffaaa..c0b3051 100644
--- a/arch/um/kernel/skas/process.c
+++ b/arch/um/kernel/skas/process.c
@@ -4,6 +4,7 @@
*/
#include <stdlib.h>
+#include <string.h>
#include <unistd.h>
#include <errno.h>
#include <signal.h>
@@ -37,17 +38,26 @@
return(1);
}
-static void handle_segv(int pid)
+void get_skas_faultinfo(int pid, struct faultinfo * fi)
{
- struct ptrace_faultinfo fault;
int err;
- err = ptrace(PTRACE_FAULTINFO, pid, 0, &fault);
+ err = ptrace(PTRACE_FAULTINFO, pid, 0, fi);
if(err)
- panic("handle_segv - PTRACE_FAULTINFO failed, errno = %d\n",
- errno);
+ panic("get_skas_faultinfo - PTRACE_FAULTINFO failed, "
+ "errno = %d\n", errno);
- segv(fault.addr, 0, FAULT_WRITE(fault.is_write), 1, NULL);
+ /* Special handling for i386, which has different structs */
+ if (sizeof(struct ptrace_faultinfo) < sizeof(struct faultinfo))
+ memset((char *)fi + sizeof(struct ptrace_faultinfo), 0,
+ sizeof(struct faultinfo) -
+ sizeof(struct ptrace_faultinfo));
+}
+
+static void handle_segv(int pid, union uml_pt_regs * regs)
+{
+ get_skas_faultinfo(pid, ®s->skas.faultinfo);
+ segv(regs->skas.faultinfo, 0, 1, NULL);
}
/*To use the same value of using_sysemu as the caller, ask it that value (in local_using_sysemu)*/
@@ -163,7 +173,7 @@
if(WIFSTOPPED(status)){
switch(WSTOPSIG(status)){
case SIGSEGV:
- handle_segv(pid);
+ handle_segv(pid, regs);
break;
case SIGTRAP + 0x80:
handle_trap(pid, regs, local_using_sysemu);
@@ -177,7 +187,7 @@
case SIGBUS:
case SIGFPE:
case SIGWINCH:
- user_signal(WSTOPSIG(status), regs);
+ user_signal(WSTOPSIG(status), regs, pid);
break;
default:
printk("userspace - child stopped with signal "
diff --git a/arch/um/kernel/skas/trap_user.c b/arch/um/kernel/skas/trap_user.c
index 8e9b46d..0dee1d9 100644
--- a/arch/um/kernel/skas/trap_user.c
+++ b/arch/um/kernel/skas/trap_user.c
@@ -5,12 +5,15 @@
#include <signal.h>
#include <errno.h>
-#include "sysdep/ptrace.h"
#include "signal_user.h"
#include "user_util.h"
#include "kern_util.h"
#include "task.h"
#include "sigcontext.h"
+#include "skas.h"
+#include "ptrace_user.h"
+#include "sysdep/ptrace.h"
+#include "sysdep/ptrace_user.h"
void sig_handler_common_skas(int sig, void *sc_ptr)
{
@@ -31,9 +34,11 @@
r = &TASK_REGS(get_current())->skas;
save_user = r->is_user;
r->is_user = 0;
- r->fault_addr = SC_FAULT_ADDR(sc);
- r->fault_type = SC_FAULT_TYPE(sc);
- r->trap_type = SC_TRAP_TYPE(sc);
+ if ( sig == SIGFPE || sig == SIGSEGV ||
+ sig == SIGBUS || sig == SIGILL ||
+ sig == SIGTRAP ) {
+ GET_FAULTINFO_FROM_SC(r->faultinfo, sc);
+ }
change_sig(SIGUSR1, 1);
info = &sig_info[sig];
@@ -45,14 +50,17 @@
r->is_user = save_user;
}
-void user_signal(int sig, union uml_pt_regs *regs)
+extern int ptrace_faultinfo;
+
+void user_signal(int sig, union uml_pt_regs *regs, int pid)
{
struct signal_info *info;
+ int segv = ((sig == SIGFPE) || (sig == SIGSEGV) || (sig == SIGBUS) ||
+ (sig == SIGILL) || (sig == SIGTRAP));
regs->skas.is_user = 1;
- regs->skas.fault_addr = 0;
- regs->skas.fault_type = 0;
- regs->skas.trap_type = 0;
+ if (segv)
+ get_skas_faultinfo(pid, ®s->skas.faultinfo);
info = &sig_info[sig];
(*info->handler)(sig, regs);