Commit 70ec3a6c authored by Russell King's avatar Russell King
Browse files

ARM: net: bpf: move stack documentation



Move the stack documentation towards the top of the file, where it's
relevant for things like the register layout.
Signed-off-by: default avatarRussell King <rmk+kernel@armlinux.org.uk>
parent d1220efd
......@@ -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
......
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