Brian Geffon bgaff

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bgaff / pkru.c

Created November 9, 2021 01:41

11th Gen Core CPU PKRU

	#include <stdint.h>
	#include <stdio.h>
	#include <stdlib.h>
	#include <assert.h>
	#include <sys/mman.h>

	static uint32_t rdpkru(void)
	{
	uint32_t ecx = 0;
	uint32_t edx, pkru;

bgaff / repro.c

Created November 8, 2021 17:26

rdpkru - Intel 11th Gen Core CPU bug

	#include <stdint.h>
	#include <stdio.h>
	#include <stdlib.h>
	#include <assert.h>
	#include <sys/mman.h>

	#define BITS_PER_PKEY 2
	static uint32_t rdpkru(void)
	{
	uint32_t ecx = 0;

bgaff / accounting_underflow.c

Last active April 20, 2020 08:12

	#define _GNU_SOURCE
	#include <sys/mman.h>
	#include <errno.h>
	#include <stdlib.h>
	#include <string.h>
	#include <stdlib.h>
	#include <unistd.h>
	#include <assert.h>

	#ifndef MREMAP_DONTUNMAP

bgaff / userfaultfd_read_block.c

Created April 16, 2020 01:13

	#define _GNU_SOURCE
	#include <stdio.h>
	#include <errno.h>
	#include <unistd.h>
	#include <assert.h>
	#include <string.h>
	#include <stdlib.h>
	#include <sys/types.h>
	#include <fcntl.h>
	#include <sys/stat.h>

bgaff / userfaultfd_close.c

Created April 12, 2020 20:01

	#define _GNU_SOURCE
	#include <stdio.h>
	#include <errno.h>
	#include <unistd.h>
	#include <assert.h>
	#include <string.h>
	#include <stdlib.h>
	#include <sys/types.h>
	#include <fcntl.h>
	#include <sys/stat.h>

bgaff / controlflow.c

Created April 5, 2020 01:08

	#include <iostream>
	#include <functional>
	#include <memory>
	#include <cstdio>

	void* _saved_return;
	void* _saved_bp;
	#define NO_INLINE __attribute__((noinline))

	#define SET_OLD_RBP() \

bgaff / defer.cpp

Created April 4, 2020 23:46

	#include <iostream>
	#include <functional>
	#include <memory>

	#define GET_RETURN_VALUE64(VAR) \
	asm ("nop\n nop\n movq %%rax,%0 \n nop\n" \
	: "=r" (VAR) \
	: \
	: "rax" \
	);

bgaff / userfaultfd_race.c

Created February 14, 2020 22:34

Example of SIGBUS caused by race handling userfaults

	#define _GNU_SOURCE
	#include <stdio.h>
	#include <errno.h>
	#include <unistd.h>
	#include <assert.h>
	#include <string.h>
	#include <stdlib.h>
	#include <sys/types.h>
	#include <sys/stat.h>
	#include <fcntl.h>

bgaff / fizzbuzz.cpp

Created April 26, 2012 05:50

FizzBuzz C++: Template Recursion

	/*
	* fizzbuzz.cpp
	*
	* Created on: Apr 25, 2012
	* Author: Brian Geffon
	*
	* fizzbuzz solved without looping or conditionals using only template recursion.
	*/

	#include <iostream>