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				git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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	 711aef1bbf
			
		
	
	
		711aef1bbf
		
	
	
	
	
		
			
			The current method to compare 64-bit numbers for conditional jump is: 1) Compare the high 32-bit first. 2) If the high 32-bit isn't the same, then goto step 4. 3) Compare the low 32-bit. 4) Check the desired condition. This method is right for unsigned comparison, but it is buggy for signed comparison, because it does signed comparison for low 32-bit too. There is only one sign bit in 64-bit number, that is the MSB in the 64-bit number, it is wrong to treat low 32-bit as signed number and do the signed comparison for it. This patch fixes the bug and adds a testcase in selftests/bpf for such bug. Signed-off-by: Wang YanQing <udknight@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
		
			
				
	
	
		
			108 lines
		
	
	
		
			2.8 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			108 lines
		
	
	
		
			2.8 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| {
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| 	"jit: lsh, rsh, arsh by 1",
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| 	.insns = {
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| 	BPF_MOV64_IMM(BPF_REG_0, 1),
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| 	BPF_MOV64_IMM(BPF_REG_1, 0xff),
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| 	BPF_ALU64_IMM(BPF_LSH, BPF_REG_1, 1),
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| 	BPF_ALU32_IMM(BPF_LSH, BPF_REG_1, 1),
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| 	BPF_JMP_IMM(BPF_JEQ, BPF_REG_1, 0x3fc, 1),
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| 	BPF_EXIT_INSN(),
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| 	BPF_ALU64_IMM(BPF_RSH, BPF_REG_1, 1),
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| 	BPF_ALU32_IMM(BPF_RSH, BPF_REG_1, 1),
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| 	BPF_JMP_IMM(BPF_JEQ, BPF_REG_1, 0xff, 1),
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| 	BPF_EXIT_INSN(),
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| 	BPF_ALU64_IMM(BPF_ARSH, BPF_REG_1, 1),
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| 	BPF_JMP_IMM(BPF_JEQ, BPF_REG_1, 0x7f, 1),
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| 	BPF_EXIT_INSN(),
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| 	BPF_MOV64_IMM(BPF_REG_0, 2),
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| 	BPF_EXIT_INSN(),
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| 	},
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| 	.result = ACCEPT,
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| 	.retval = 2,
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| },
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| {
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| 	"jit: mov32 for ldimm64, 1",
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| 	.insns = {
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| 	BPF_MOV64_IMM(BPF_REG_0, 2),
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| 	BPF_LD_IMM64(BPF_REG_1, 0xfeffffffffffffffULL),
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| 	BPF_ALU64_IMM(BPF_RSH, BPF_REG_1, 32),
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| 	BPF_LD_IMM64(BPF_REG_2, 0xfeffffffULL),
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| 	BPF_JMP_REG(BPF_JEQ, BPF_REG_1, BPF_REG_2, 1),
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| 	BPF_MOV64_IMM(BPF_REG_0, 1),
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| 	BPF_EXIT_INSN(),
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| 	},
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| 	.result = ACCEPT,
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| 	.retval = 2,
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| },
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| {
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| 	"jit: mov32 for ldimm64, 2",
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| 	.insns = {
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| 	BPF_MOV64_IMM(BPF_REG_0, 1),
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| 	BPF_LD_IMM64(BPF_REG_1, 0x1ffffffffULL),
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| 	BPF_LD_IMM64(BPF_REG_2, 0xffffffffULL),
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| 	BPF_JMP_REG(BPF_JEQ, BPF_REG_1, BPF_REG_2, 1),
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| 	BPF_MOV64_IMM(BPF_REG_0, 2),
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| 	BPF_EXIT_INSN(),
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| 	},
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| 	.result = ACCEPT,
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| 	.retval = 2,
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| },
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| {
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| 	"jit: various mul tests",
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| 	.insns = {
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| 	BPF_LD_IMM64(BPF_REG_2, 0xeeff0d413122ULL),
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| 	BPF_LD_IMM64(BPF_REG_0, 0xfefefeULL),
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| 	BPF_LD_IMM64(BPF_REG_1, 0xefefefULL),
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| 	BPF_ALU64_REG(BPF_MUL, BPF_REG_0, BPF_REG_1),
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| 	BPF_JMP_REG(BPF_JEQ, BPF_REG_0, BPF_REG_2, 2),
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| 	BPF_MOV64_IMM(BPF_REG_0, 1),
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| 	BPF_EXIT_INSN(),
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| 	BPF_LD_IMM64(BPF_REG_3, 0xfefefeULL),
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| 	BPF_ALU64_REG(BPF_MUL, BPF_REG_3, BPF_REG_1),
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| 	BPF_JMP_REG(BPF_JEQ, BPF_REG_3, BPF_REG_2, 2),
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| 	BPF_MOV64_IMM(BPF_REG_0, 1),
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| 	BPF_EXIT_INSN(),
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| 	BPF_MOV32_REG(BPF_REG_2, BPF_REG_2),
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| 	BPF_LD_IMM64(BPF_REG_0, 0xfefefeULL),
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| 	BPF_ALU32_REG(BPF_MUL, BPF_REG_0, BPF_REG_1),
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| 	BPF_JMP_REG(BPF_JEQ, BPF_REG_0, BPF_REG_2, 2),
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| 	BPF_MOV64_IMM(BPF_REG_0, 1),
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| 	BPF_EXIT_INSN(),
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| 	BPF_LD_IMM64(BPF_REG_3, 0xfefefeULL),
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| 	BPF_ALU32_REG(BPF_MUL, BPF_REG_3, BPF_REG_1),
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| 	BPF_JMP_REG(BPF_JEQ, BPF_REG_3, BPF_REG_2, 2),
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| 	BPF_MOV64_IMM(BPF_REG_0, 1),
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| 	BPF_EXIT_INSN(),
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| 	BPF_LD_IMM64(BPF_REG_0, 0x952a7bbcULL),
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| 	BPF_LD_IMM64(BPF_REG_1, 0xfefefeULL),
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| 	BPF_LD_IMM64(BPF_REG_2, 0xeeff0d413122ULL),
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| 	BPF_ALU32_REG(BPF_MUL, BPF_REG_2, BPF_REG_1),
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| 	BPF_JMP_REG(BPF_JEQ, BPF_REG_2, BPF_REG_0, 2),
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| 	BPF_MOV64_IMM(BPF_REG_0, 1),
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| 	BPF_EXIT_INSN(),
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| 	BPF_MOV64_IMM(BPF_REG_0, 2),
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| 	BPF_EXIT_INSN(),
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| 	},
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| 	.result = ACCEPT,
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| 	.retval = 2,
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| },
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| {
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| 	"jit: jsgt, jslt",
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| 	.insns = {
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| 	BPF_LD_IMM64(BPF_REG_1, 0x80000000ULL),
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| 	BPF_LD_IMM64(BPF_REG_2, 0x0ULL),
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| 	BPF_JMP_REG(BPF_JSGT, BPF_REG_1, BPF_REG_2, 2),
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| 	BPF_MOV64_IMM(BPF_REG_0, 1),
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| 	BPF_EXIT_INSN(),
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| 
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| 	BPF_JMP_REG(BPF_JSLT, BPF_REG_2, BPF_REG_1, 2),
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| 	BPF_MOV64_IMM(BPF_REG_0, 1),
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| 	BPF_EXIT_INSN(),
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| 
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| 	BPF_MOV64_IMM(BPF_REG_0, 2),
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| 	BPF_EXIT_INSN(),
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| 	},
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| 	.result = ACCEPT,
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| 	.retval = 2,
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| },
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