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| author | fishsoupisgood <github@madingley.org> | 2019-04-29 01:17:54 +0100 |
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| committer | fishsoupisgood <github@madingley.org> | 2019-05-27 03:43:43 +0100 |
| commit | 3f2546b2ef55b661fd8dd69682b38992225e86f6 (patch) | |
| tree | 65ca85f13617aee1dce474596800950f266a456c /roms/ipxe/src/arch/i386/core/nulltrap.c | |
| download | qemu-master.tar.gz qemu-master.tar.bz2 qemu-master.zip | |
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 ) {} +} |