diff options
Diffstat (limited to 'roms/ipxe/src/arch/i386/core/nulltrap.c')
| -rw-r--r-- | roms/ipxe/src/arch/i386/core/nulltrap.c | 51 |
1 files changed, 51 insertions, 0 deletions
diff --git a/roms/ipxe/src/arch/i386/core/nulltrap.c b/roms/ipxe/src/arch/i386/core/nulltrap.c new file mode 100644 index 00000000..3046fbec --- /dev/null +++ b/roms/ipxe/src/arch/i386/core/nulltrap.c @@ -0,0 +1,51 @@ +#include <stdint.h> +#include <stdio.h> + +__attribute__ (( noreturn, section ( ".text.null_trap" ) )) +void null_function_trap ( void ) { + void *stack; + + /* 128 bytes of NOPs; the idea of this is that if something + * dereferences a NULL pointer and overwrites us, we at least + * have some chance of still getting to execute the printf() + * statement. + */ + __asm__ __volatile__ ( "nop ; nop ; nop ; nop" ); + __asm__ __volatile__ ( "nop ; nop ; nop ; nop" ); + __asm__ __volatile__ ( "nop ; nop ; nop ; nop" ); + __asm__ __volatile__ ( "nop ; nop ; nop ; nop" ); + __asm__ __volatile__ ( "nop ; nop ; nop ; nop" ); + __asm__ __volatile__ ( "nop ; nop ; nop ; nop" ); + __asm__ __volatile__ ( "nop ; nop ; nop ; nop" ); + __asm__ __volatile__ ( "nop ; nop ; nop ; nop" ); + __asm__ __volatile__ ( "nop ; nop ; nop ; nop" ); + __asm__ __volatile__ ( "nop ; nop ; nop ; nop" ); + __asm__ __volatile__ ( "nop ; nop ; nop ; nop" ); + __asm__ __volatile__ ( "nop ; nop ; nop ; nop" ); + __asm__ __volatile__ ( "nop ; nop ; nop ; nop" ); + __asm__ __volatile__ ( "nop ; nop ; nop ; nop" ); + __asm__ __volatile__ ( "nop ; nop ; nop ; nop" ); + __asm__ __volatile__ ( "nop ; nop ; nop ; nop" ); + __asm__ __volatile__ ( "nop ; nop ; nop ; nop" ); + __asm__ __volatile__ ( "nop ; nop ; nop ; nop" ); + __asm__ __volatile__ ( "nop ; nop ; nop ; nop" ); + __asm__ __volatile__ ( "nop ; nop ; nop ; nop" ); + __asm__ __volatile__ ( "nop ; nop ; nop ; nop" ); + __asm__ __volatile__ ( "nop ; nop ; nop ; nop" ); + __asm__ __volatile__ ( "nop ; nop ; nop ; nop" ); + __asm__ __volatile__ ( "nop ; nop ; nop ; nop" ); + __asm__ __volatile__ ( "nop ; nop ; nop ; nop" ); + __asm__ __volatile__ ( "nop ; nop ; nop ; nop" ); + __asm__ __volatile__ ( "nop ; nop ; nop ; nop" ); + __asm__ __volatile__ ( "nop ; nop ; nop ; nop" ); + __asm__ __volatile__ ( "nop ; nop ; nop ; nop" ); + __asm__ __volatile__ ( "nop ; nop ; nop ; nop" ); + __asm__ __volatile__ ( "nop ; nop ; nop ; nop" ); + __asm__ __volatile__ ( "nop ; nop ; nop ; nop" ); + + __asm__ __volatile__ ( "movl %%esp, %0" : "=r" ( stack ) ); + printf ( "NULL method called from %p (stack %p)\n", + __builtin_return_address ( 0 ), stack ); + DBG_HD ( stack, 256 ); + while ( 1 ) {} +} |