Commit f9dfefe4 authored by Bodo Stroesser's avatar Bodo Stroesser Committed by Linus Torvalds

[PATCH] uml: fix advanced sysemu check

cleanup and fix the check for advanced sysemu (PTRACE_SYSEMU_SINGLESTEP
option)
Signed-off-by: default avatarBodo Stroesser <bstroesser@fujitsu-siemens.com>
Signed-off-by: default avatarJeff Dike <jdike@addtoit.com>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent d9838d86
......@@ -161,7 +161,7 @@ __uml_setup("nosysemu", nosysemu_cmd_param,
static void __init check_sysemu(void)
{
void *stack;
int pid, syscall, n, status, count=0;
int pid, n, status, count=0;
printk("Checking syscall emulation patch for ptrace...");
sysemu_supported = 0;
......@@ -192,6 +192,12 @@ static void __init check_sysemu(void)
printk("Checking advanced syscall emulation patch for ptrace...");
pid = start_ptraced_child(&stack);
if(ptrace(PTRACE_OLDSETOPTIONS, pid, 0,
(void *) PTRACE_O_TRACESYSGOOD) < 0)
panic("check_ptrace: PTRACE_OLDSETOPTIONS failed, errno = %d",
errno);
while(1){
count++;
if(ptrace(PTRACE_SYSEMU_SINGLESTEP, pid, 0, 0) < 0)
......@@ -199,15 +205,10 @@ static void __init check_sysemu(void)
CATCH_EINTR(n = waitpid(pid, &status, WUNTRACED));
if(n < 0)
panic("check_ptrace : wait failed, errno = %d", errno);
if(!WIFSTOPPED(status) || (WSTOPSIG(status) != SIGTRAP))
panic("check_ptrace : expected (SIGTRAP|SYSCALL_TRAP), "
"got status = %d", status);
syscall = ptrace(PTRACE_PEEKUSR, pid, PT_SYSCALL_NR_OFFSET,
0);
if(syscall == __NR_getpid){
if(WIFSTOPPED(status) && (WSTOPSIG(status) == (SIGTRAP|0x80))){
if (!count)
panic("check_ptrace : SYSEMU_SINGLESTEP doesn't singlestep");
panic("check_ptrace : SYSEMU_SINGLESTEP "
"doesn't singlestep");
n = ptrace(PTRACE_POKEUSR, pid, PT_SYSCALL_RET_OFFSET,
os_getpid());
if(n < 0)
......@@ -215,6 +216,11 @@ static void __init check_sysemu(void)
"call return, errno = %d", errno);
break;
}
else if(WIFSTOPPED(status) && (WSTOPSIG(status) == SIGTRAP))
count++;
else
panic("check_ptrace : expected SIGTRAP or "
"(SIGTRAP|0x80), got status = %d", status);
}
if (stop_ptraced_child(pid, stack, 0, 0) < 0)
goto fail_stopped;
......@@ -250,8 +256,8 @@ static void __init check_ptrace(void)
CATCH_EINTR(n = waitpid(pid, &status, WUNTRACED));
if(n < 0)
panic("check_ptrace : wait failed, errno = %d", errno);
if(!WIFSTOPPED(status) || (WSTOPSIG(status) != SIGTRAP + 0x80))
panic("check_ptrace : expected SIGTRAP + 0x80, "
if(!WIFSTOPPED(status) || (WSTOPSIG(status) != (SIGTRAP|0x80)))
panic("check_ptrace : expected (SIGTRAP|0x80), "
"got status = %d", status);
syscall = ptrace(PTRACE_PEEKUSR, pid, PT_SYSCALL_NR_OFFSET,
......
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