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| author | Michael Brown | 2006-06-11 03:48:29 +0200 |
|---|---|---|
| committer | Michael Brown | 2006-06-11 03:48:29 +0200 |
| commit | df4b503a8c138edc0fdcfe920c7d6b6629cd2971 (patch) | |
| tree | 0b32e858aa746c05b397816117ec0805f3eb80c4 /src | |
| parent | Update to use the generic i2c bit-bashing code. (diff) | |
| download | ipxe-df4b503a8c138edc0fdcfe920c7d6b6629cd2971.tar.gz ipxe-df4b503a8c138edc0fdcfe920c7d6b6629cd2971.tar.xz ipxe-df4b503a8c138edc0fdcfe920c7d6b6629cd2971.zip | |
Added null trap code for debugging. (Must be included by adding
--nulltrap to the make target at the moment.)
Diffstat (limited to 'src')
| -rw-r--r-- | src/arch/i386/core/nulltrap.c | 48 | ||||
| -rw-r--r-- | src/arch/i386/scripts/i386.lds | 1 |
2 files changed, 49 insertions, 0 deletions
diff --git a/src/arch/i386/core/nulltrap.c b/src/arch/i386/core/nulltrap.c new file mode 100644 index 000000000..bd4b75774 --- /dev/null +++ b/src/arch/i386/core/nulltrap.c @@ -0,0 +1,48 @@ +#include <stdint.h> +#include <vsprintf.h> + +__attribute__ (( noreturn, section ( ".text.null_trap" ) )) +void null_function_trap ( void ) { + + /* 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" ); + + printf ( "NULL method called from %p\n", + __builtin_return_address ( 0 ) ); + while ( 1 ) {} +} diff --git a/src/arch/i386/scripts/i386.lds b/src/arch/i386/scripts/i386.lds index 4a984a956..48dd777c9 100644 --- a/src/arch/i386/scripts/i386.lds +++ b/src/arch/i386/scripts/i386.lds @@ -117,6 +117,7 @@ SECTIONS { .text : AT ( _textdata_load_offset + __text ) { __text = .; + *(.text.null_trap) *(.text) *(.text.*) } = 0x9090 |