From: Andy Whitcroft There seems to be code recently added to -bk and thereby -mm which supports extra debug for preempt on system call exit. Oddly there doesn't seem to be configuration options to enable them. Below is a possible patch to allow enabling this on i386. Sadly the most obvious menu to add this to is the Kernel Hacking menu, but that is defined in architecture specific configuration. If this makes sense I could patch the other arches? Add a configuration option to allow enabling TRAP_BAD_SYSCALL_EXITS to the Kernel Hacking menu. Signed-off-by: Andy Whitcroft Signed-off-by: Andrew Morton --- 25-akpm/arch/i386/Kconfig | 7 +++++++ 1 files changed, 7 insertions(+) diff -puN arch/i386/Kconfig~add-trap_bad_syscall_exits-config-for-i386 arch/i386/Kconfig --- 25/arch/i386/Kconfig~add-trap_bad_syscall_exits-config-for-i386 Fri Jul 2 16:32:02 2004 +++ 25-akpm/arch/i386/Kconfig Fri Jul 2 16:32:02 2004 @@ -1483,6 +1483,13 @@ config X86_MPPARSE depends on X86_LOCAL_APIC && !X86_VISWS default y +config TRAP_BAD_SYSCALL_EXITS + bool "Debug bad system call exits" + help + If you say Y here the kernel will check for system calls which + return without clearing preempt. + default n + endmenu source "security/Kconfig" _