From: <blaisorblade_spam@yahoo.it>
- Correct some silly errors (dereferencing a pointer before checking if it's
!= NULL when creating /proc/sysemu, some error messages)
- separate using_sysemu from sysemu_supported (so to refuse to activate
sysemu if it is not supported, avoiding panics)
- not probe sysemu if in tt mode.
Signed-off-by: <blaisorblade_spam@yahoo.it>
Signed-off-by: Andrew Morton <akpm@osdl.org>
---
25-akpm/arch/um/kernel/process.c | 80 ++++++++++++----------
25-akpm/arch/um/kernel/skas/include/ptrace-skas.h | 1
25-akpm/arch/um/kernel/skas/process.c | 9 +-
25-akpm/arch/um/kernel/skas/process_kern.c | 14 ++-
4 files changed, 58 insertions(+), 46 deletions(-)
diff -puN arch/um/kernel/process.c~uml-fix-for-sysemu-patches arch/um/kernel/process.c
--- 25/arch/um/kernel/process.c~uml-fix-for-sysemu-patches 2004-07-05 16:00:46.556942720 -0700
+++ 25-akpm/arch/um/kernel/process.c 2004-07-05 16:00:46.565941352 -0700
@@ -212,6 +212,49 @@ __uml_setup("nosysemu", nosysemu_cmd_par
" To make it working, you need a kernel patch for your host, too.\n"
" See http://perso.wanadoo.fr/laurent.vivier/UML/ for further information.\n");
+static void __init check_sysemu(void)
+{
+ void *stack;
+ int pid, n, status;
+
+ if (mode_tt)
+ return;
+
+ printk("Checking syscall emulation patch for ptrace...");
+ sysemu_supported = 0;
+ pid = start_ptraced_child(&stack);
+ if(ptrace(PTRACE_SYSEMU, pid, 0, 0) >= 0) {
+ struct user_regs_struct regs;
+
+ if (waitpid(pid, &status, WUNTRACED) < 0)
+ panic("check_ptrace : wait failed, errno = %d", errno);
+ if(!WIFSTOPPED(status) || (WSTOPSIG(status) != SIGTRAP))
+ panic("check_ptrace : expected SIGTRAP, "
+ "got status = %d", status);
+
+ if (ptrace(PTRACE_GETREGS, pid, 0, ®s) < 0)
+ panic("check_ptrace : failed to read child "
+ "registers, errno = %d", errno);
+ regs.orig_eax = pid;
+ if (ptrace(PTRACE_SETREGS, pid, 0, ®s) < 0)
+ panic("check_ptrace : failed to modify child "
+ "registers, errno = %d", errno);
+
+ stop_ptraced_child(pid, stack, 0);
+
+ sysemu_supported = 1;
+ printk("found\n");
+ }
+ else
+ {
+ stop_ptraced_child(pid, stack, 1);
+ sysemu_supported = 0;
+ printk("missing\n");
+ }
+
+ set_using_sysemu(!force_sysemu_disabled);
+}
+
void __init check_ptrace(void)
{
void *stack;
@@ -244,42 +287,7 @@ void __init check_ptrace(void)
}
stop_ptraced_child(pid, stack, 0);
printk("OK\n");
-
- printk("Checking syscall emulation patch for ptrace...");
- set_using_sysemu(0);
- pid = start_ptraced_child(&stack);
- if(ptrace(PTRACE_SYSEMU, pid, 0, 0) >= 0) {
- struct user_regs_struct regs;
-
- if (waitpid(pid, &status, WUNTRACED) < 0)
- panic("check_ptrace : wait failed, errno = %d", errno);
- if(!WIFSTOPPED(status) || (WSTOPSIG(status) != SIGTRAP))
- panic("check_ptrace : expected SIGTRAP, "
- "got status = %d", status);
-
- if (ptrace(PTRACE_GETREGS, pid, 0, ®s) < 0)
- panic("check_ptrace : failed to read child "
- "registers, errno = %d", errno);
- regs.orig_eax = pid;
- if (ptrace(PTRACE_SETREGS, pid, 0, ®s) < 0)
- panic("check_ptrace : failed to modify child "
- "registers, errno = %d", errno);
-
- stop_ptraced_child(pid, stack, 0);
-
- if (!force_sysemu_disabled) {
- printk("found\n");
- set_using_sysemu(1);
- } else {
- printk("found but disabled\n");
- }
- }
- else
- {
- printk("missing\n");
- stop_ptraced_child(pid, stack, 1);
- }
-
+ check_sysemu();
}
int run_kernel_thread(int (*fn)(void *), void *arg, void **jmp_ptr)
diff -puN arch/um/kernel/skas/include/ptrace-skas.h~uml-fix-for-sysemu-patches arch/um/kernel/skas/include/ptrace-skas.h
--- 25/arch/um/kernel/skas/include/ptrace-skas.h~uml-fix-for-sysemu-patches 2004-07-05 16:00:46.558942416 -0700
+++ 25-akpm/arch/um/kernel/skas/include/ptrace-skas.h 2004-07-05 16:00:46.566941200 -0700
@@ -18,6 +18,7 @@
void set_using_sysemu(int value);
int get_using_sysemu(void);
+extern int sysemu_supported;
#include "skas_ptregs.h"
diff -puN arch/um/kernel/skas/process.c~uml-fix-for-sysemu-patches arch/um/kernel/skas/process.c
--- 25/arch/um/kernel/skas/process.c~uml-fix-for-sysemu-patches 2004-07-05 16:00:46.559942264 -0700
+++ 25-akpm/arch/um/kernel/skas/process.c 2004-07-05 16:00:46.566941200 -0700
@@ -151,8 +151,8 @@ void userspace(union uml_pt_regs *regs)
else
err = ptrace(PTRACE_SYSCALL, pid, 0, 0);
if(err)
- panic("userspace - PTRACE_SYSCALL failed, errno = %d\n",
- errno);
+ panic("userspace - PTRACE_%s failed, errno = %d\n",
+ local_using_sysemu ? "SYSEMU" : "SYSCALL", errno);
while(1){
err = waitpid(pid, &status, WUNTRACED);
if(err < 0)
@@ -199,8 +199,9 @@ void userspace(union uml_pt_regs *regs)
err = ptrace(op, pid, 0, 0);
if(err)
- panic("userspace - PTRACE_SYSCALL failed, "
- "errno = %d\n", errno);
+ panic("userspace - PTRACE_%s failed, "
+ "errno = %d\n",
+ local_using_sysemu ? "SYSEMU" : "SYSCALL", errno);
}
}
diff -puN arch/um/kernel/skas/process_kern.c~uml-fix-for-sysemu-patches arch/um/kernel/skas/process_kern.c
--- 25/arch/um/kernel/skas/process_kern.c~uml-fix-for-sysemu-patches 2004-07-05 16:00:46.560942112 -0700
+++ 25-akpm/arch/um/kernel/skas/process_kern.c 2004-07-05 16:00:46.567941048 -0700
@@ -23,13 +23,12 @@
#include "kern.h"
#include "mode.h"
-#ifdef PTRACE_SYSEMU
static atomic_t using_sysemu;
-#endif
+int sysemu_supported;
void set_using_sysemu(int value)
{
- atomic_set(&using_sysemu, value);
+ atomic_set(&using_sysemu, sysemu_supported && value);
}
int get_using_sysemu(void)
@@ -60,10 +59,10 @@ int proc_write_sysemu(struct file *file,
int __init make_proc_sysemu(void)
{
struct proc_dir_entry *ent;
+ if (mode_tt || !sysemu_supported)
+ return 0;
- ent = create_proc_entry("sysemu", 00600, &proc_root);
- ent->read_proc = proc_read_sysemu;
- ent->write_proc = proc_write_sysemu;
+ ent = create_proc_entry("sysemu", 0600, &proc_root);
if (ent == NULL)
{
@@ -71,6 +70,9 @@ int __init make_proc_sysemu(void)
return(0);
}
+ ent->read_proc = proc_read_sysemu;
+ ent->write_proc = proc_write_sysemu;
+
return 0;
}
_