ARM: net: bpf: move stack documentation (70ec3a6c) · Commits · 戴 / test

arch/arm/net/bpf_jit_32.c

+21 −21

Original line number	Diff line number	Diff line
		@@ -27,6 +27,27 @@

		int bpf_jit_enable __read_mostly;

		/*
		* eBPF prog stack layout
		*
		* high
		* original ARM_SP => +-----+ eBPF prologue
		* \|FP/LR\|
		* current ARM_FP => +-----+
		* \| ... \| callee saved registers
		* eBPF fp register => +-----+ <= (BPF_FP)
		* \| ... \| eBPF JIT scratch space
		* \| \| eBPF prog stack
		* +-----+
		* \|RSVD \| JIT scratchpad
		* current ARM_SP => +-----+ <= (BPF_FP - STACK_SIZE)
		* \| \|
		* \| ... \| Function call stack
		* \| \|
		* +-----+
		* low
		*/

		#define STACK_OFFSET(k) (k)
		#define TMP_REG_1 (MAX_BPF_JIT_REG + 0) /* TEMP Register 1 */
		#define TMP_REG_2 (MAX_BPF_JIT_REG + 1) /* TEMP Register 2 */
		@@ -1091,27 +1112,6 @@ static void build_prologue(struct jit_ctx *ctx)

		u16 reg_set = 0;

		/*
		* eBPF prog stack layout
		*
		* high
		* original ARM_SP => +-----+ eBPF prologue
		* \|FP/LR\|
		* current ARM_FP => +-----+
		* \| ... \| callee saved registers
		* eBPF fp register => +-----+ <= (BPF_FP)
		* \| ... \| eBPF JIT scratch space
		* \| \| eBPF prog stack
		* +-----+
		* \|RSVD \| JIT scratchpad
		* current A64_SP => +-----+ <= (BPF_FP - STACK_SIZE)
		* \| \|
		* \| ... \| Function call stack
		* \| \|
		* +-----+
		* low
		*/

		/* Save callee saved registers. */
		reg_set \|= (1<<r4) \| (1<<r5) \| (1<<r6) \| (1<<r7) \| (1<<r8) \| (1<<r10);
		#ifdef CONFIG_FRAME_POINTER