From: Jeff Dike <jdike@addtoit.com>
The patch syscall-security-3 is wrong (provided by me, sorry). I missed,
that singlestepping_skas() used to reset PT_DTRACE. This was handled
differently in tt and skas. With syscall-security-3 applied, a process in
SKAS that singlestepped once continues to singlestep until the next
systemcall occurs, even if it is resumed with PTRACE_CONT or
PTRACE_SYSCALL.
This fix unifies the usage of PT_DTRACE in TT and SKAS. PT_DTRACE now is
set by ptrace(PTRACE_SINGLESTEP,...) and reset by singlestepping() and it
is evaluated in kern_do_signal().
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>
---
25-akpm/arch/um/kernel/process_kern.c | 8 +++++++-
25-akpm/arch/um/kernel/skas/syscall_kern.c | 1 -
25-akpm/arch/um/kernel/tt/include/tt.h | 1 -
25-akpm/arch/um/kernel/tt/process_kern.c | 7 -------
25-akpm/arch/um/kernel/tt/syscall_kern.c | 1 -
25-akpm/arch/um/kernel/tt/tracer.c | 1 -
6 files changed, 7 insertions(+), 12 deletions(-)
diff -puN arch/um/kernel/process_kern.c~uml-clear-singlestep arch/um/kernel/process_kern.c
--- 25/arch/um/kernel/process_kern.c~uml-clear-singlestep 2004-11-04 20:41:41.074767096 -0800
+++ 25-akpm/arch/um/kernel/process_kern.c 2004-11-04 20:41:41.085765424 -0800
@@ -459,9 +459,15 @@ int singlestepping(void * t)
{
struct task_struct *task = t ? t : current;
+ if ( ! (task->ptrace & PT_DTRACE) )
+ return(0);
+
+ task->ptrace &= ~PT_DTRACE;
+
if (task->thread.singlestep_syscall)
return(0);
- return(task->ptrace & PT_DTRACE);
+
+ return 1;
}
/*
diff -puN arch/um/kernel/skas/syscall_kern.c~uml-clear-singlestep arch/um/kernel/skas/syscall_kern.c
--- 25/arch/um/kernel/skas/syscall_kern.c~uml-clear-singlestep 2004-11-04 20:41:41.075766944 -0800
+++ 25-akpm/arch/um/kernel/skas/syscall_kern.c 2004-11-04 20:41:41.086765272 -0800
@@ -30,7 +30,6 @@ long execute_syscall_skas(void *r)
if(current->thread.singlestep_syscall){
current->thread.singlestep_syscall = 0;
- current->ptrace &= ~PT_DTRACE;
force_sig(SIGTRAP, current);
}
diff -puN arch/um/kernel/tt/include/tt.h~uml-clear-singlestep arch/um/kernel/tt/include/tt.h
--- 25/arch/um/kernel/tt/include/tt.h~uml-clear-singlestep 2004-11-04 20:41:41.077766640 -0800
+++ 25-akpm/arch/um/kernel/tt/include/tt.h 2004-11-04 20:41:41.086765272 -0800
@@ -24,7 +24,6 @@ extern void set_init_pid(int pid);
extern int set_user_mode(void *task);
extern void set_tracing(void *t, int tracing);
extern int is_tracing(void *task);
-extern void clear_singlestep(void *t);
extern void syscall_handler(int sig, union uml_pt_regs *regs);
extern void exit_kernel(int pid, void *task);
extern int do_syscall(void *task, int pid, int local_using_sysemu);
diff -puN arch/um/kernel/tt/process_kern.c~uml-clear-singlestep arch/um/kernel/tt/process_kern.c
--- 25/arch/um/kernel/tt/process_kern.c~uml-clear-singlestep 2004-11-04 20:41:41.079766336 -0800
+++ 25-akpm/arch/um/kernel/tt/process_kern.c 2004-11-04 20:41:41.087765120 -0800
@@ -523,13 +523,6 @@ void set_init_pid(int pid)
-err);
}
-void clear_singlestep(void *t)
-{
- struct task_struct *task = t;
-
- task->ptrace &= ~PT_DTRACE;
-}
-
int start_uml_tt(void)
{
void *sp;
diff -puN arch/um/kernel/tt/syscall_kern.c~uml-clear-singlestep arch/um/kernel/tt/syscall_kern.c
--- 25/arch/um/kernel/tt/syscall_kern.c~uml-clear-singlestep 2004-11-04 20:41:41.080766184 -0800
+++ 25-akpm/arch/um/kernel/tt/syscall_kern.c 2004-11-04 20:41:41.087765120 -0800
@@ -125,7 +125,6 @@ long execute_syscall_tt(void *r)
if(current->thread.singlestep_syscall){
current->thread.singlestep_syscall = 0;
- current->ptrace &= ~PT_DTRACE;
force_sig(SIGTRAP, current);
}
diff -puN arch/um/kernel/tt/tracer.c~uml-clear-singlestep arch/um/kernel/tt/tracer.c
--- 25/arch/um/kernel/tt/tracer.c~uml-clear-singlestep 2004-11-04 20:41:41.082765880 -0800
+++ 25-akpm/arch/um/kernel/tt/tracer.c 2004-11-04 20:41:41.088764968 -0800
@@ -336,7 +336,6 @@ int tracer(int (*init_proc)(void *), voi
tracing = 0;
if(do_syscall(task, pid, local_using_sysemu))
sig = SIGUSR2;
- else clear_singlestep(task);
break;
case SIGPROF:
if(tracing) sig = 0;
_