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| author | Russell King <rmk+kernel@armlinux.org.uk> | 2018-01-13 21:26:14 +0000 |
|---|---|---|
| committer | Russell King <rmk+kernel@armlinux.org.uk> | 2018-01-17 19:36:43 +0000 |
| commit | 70ec3a6c2c11e4b0e107a65de943a082f9aff351 (patch) | |
| tree | 8d342d7ef860cf6cb6600fdd4dbeda43a6e5123d /arch | |
| parent | d1220efd23484c72c82d5471f05daeb35b5d1916 (diff) | |
| download | lwn-70ec3a6c2c11e4b0e107a65de943a082f9aff351.tar.gz lwn-70ec3a6c2c11e4b0e107a65de943a082f9aff351.zip | |
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: Russell King <rmk+kernel@armlinux.org.uk>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/arm/net/bpf_jit_32.c | 42 |
1 files changed, 21 insertions, 21 deletions
diff --git a/arch/arm/net/bpf_jit_32.c b/arch/arm/net/bpf_jit_32.c index d00a0eb0386e..e90229d58c77 100644 --- a/arch/arm/net/bpf_jit_32.c +++ b/arch/arm/net/bpf_jit_32.c @@ -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 |