coerce_reg_to_size

Name:runcate register to smaller size (in bytes)* must be called with size < BPF_REG_SIZE

Proto:static void coerce_reg_to_size(struct bpf_reg_state *reg, int size)

Type:void

Parameter:

Type	Parameter	Name
struct bpf_reg_state *	reg
int	size

2799

For scalar types (SCALAR_VALUE), this represents our knowledge of * the actual value. * For pointer types, this represents the variable part of the offset * from the pointed-to object, and is shared with all bpf_reg_states * with the same id as us. = Return @a with all but the lowest @size bytes cleared

2802

mask = (1 << size * 8 ) - 1

2803

If ( minimum possible (u64)value & ~mask) == ( maximum possible (u64)value & ~mask) Then

2804

minimum possible (u64)value &= mask

2805

maximum possible (u64)value &= mask

2806

Else

2807

minimum possible (u64)value = 0

2808

maximum possible (u64)value = mask

2810

minimum possible (s64)value = minimum possible (u64)value

2811

maximum possible (s64)value = maximum possible (u64)value

**Caller**
Name	Describe
check_mem_access	heck whether memory at (regno + off) is accessible for t = (read \| write)* if t==write, value_regno is a register which value is stored into memory* if t==read, value_regno is a register which will receive the value from memory* if t==write &&
adjust_scalar_min_max_vals	WARNING: This function does calculations on 64-bit values, but the actual* execution may occur on 32-bit values. Therefore, things like bitshifts* need extra checks in the 32-bit case.
check_alu_op	heck validity of 32-bit and 64-bit arithmetic operations
is_branch_taken	mpute branch direction of the expression "if (reg opcode val) goto target;"* and return:* 1 - branch will be taken and "goto target" will be executed* 0 - branch will not be taken and fall-through to next insn* -1 - unknown
check_cond_jmp_op

Source code conversion tool public plug-in interface	X
Support c/c++/esqlc/java Oracle/Informix/Mysql Plug-in can realize: logical Report Code generation and batch code conversion