From: Daniel Borkmann <daniel@iogearbox.net>
To: alexei.starovoitov@gmail.com
Cc: netdev@vger.kernel.org, Daniel Borkmann <daniel@iogearbox.net>
Subject: [PATCH bpf-next v2 5/8] bpf, arm64: save 4 bytes of unneeded stack space
Date: Mon, 14 May 2018 23:22:31 +0200 [thread overview]
Message-ID: <20180514212234.2661-6-daniel@iogearbox.net> (raw)
In-Reply-To: <20180514212234.2661-1-daniel@iogearbox.net>
Follow-up to 816d9ef32a8b ("bpf, arm64: remove ld_abs/ld_ind") in
that the extra 4 byte JIT scratchpad is not needed anymore since it
was in ld_abs/ld_ind as stack buffer for bpf_load_pointer().
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
---
arch/arm64/net/bpf_jit_comp.c | 7 ++-----
1 file changed, 2 insertions(+), 5 deletions(-)
diff --git a/arch/arm64/net/bpf_jit_comp.c b/arch/arm64/net/bpf_jit_comp.c
index 0b40c8f..85113ca 100644
--- a/arch/arm64/net/bpf_jit_comp.c
+++ b/arch/arm64/net/bpf_jit_comp.c
@@ -21,7 +21,6 @@
#include <linux/bpf.h>
#include <linux/filter.h>
#include <linux/printk.h>
-#include <linux/skbuff.h>
#include <linux/slab.h>
#include <asm/byteorder.h>
@@ -188,7 +187,7 @@ static int build_prologue(struct jit_ctx *ctx)
* | ... | BPF prog stack
* | |
* +-----+ <= (BPF_FP - prog->aux->stack_depth)
- * |RSVD | JIT scratchpad
+ * |RSVD | padding
* current A64_SP => +-----+ <= (BPF_FP - ctx->stack_size)
* | |
* | ... | Function call stack
@@ -220,9 +219,7 @@ static int build_prologue(struct jit_ctx *ctx)
return -1;
}
- /* 4 byte extra for skb_copy_bits buffer */
- ctx->stack_size = prog->aux->stack_depth + 4;
- ctx->stack_size = STACK_ALIGN(ctx->stack_size);
+ ctx->stack_size = STACK_ALIGN(prog->aux->stack_depth);
/* Set up function call stack */
emit(A64_SUB_I(1, A64_SP, A64_SP, ctx->stack_size), ctx);
--
2.9.5
next prev parent reply other threads:[~2018-05-14 21:22 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-05-14 21:22 [PATCH bpf-next v2 0/8] Minor follow-up cleanups in BPF JITs and optimized imm emission Daniel Borkmann
2018-05-14 21:22 ` [PATCH bpf-next v2 1/8] bpf, mips: remove unused function Daniel Borkmann
2018-05-14 21:22 ` [PATCH bpf-next v2 2/8] bpf, sparc: remove unused variable Daniel Borkmann
2018-05-14 21:22 ` [PATCH bpf-next v2 3/8] bpf, x64: clean up retpoline emission slightly Daniel Borkmann
2018-05-14 21:22 ` [PATCH bpf-next v2 4/8] bpf, arm32: save 4 bytes of unneeded stack space Daniel Borkmann
2018-05-14 21:22 ` Daniel Borkmann [this message]
2018-05-14 21:22 ` [PATCH bpf-next v2 6/8] bpf, arm64: optimize 32/64 immediate emission Daniel Borkmann
2018-05-14 21:22 ` [PATCH bpf-next v2 7/8] bpf, arm64: save 4 bytes in prologue when ebpf insns came from cbpf Daniel Borkmann
2018-05-14 21:22 ` [PATCH bpf-next v2 8/8] bpf: add ld64 imm test cases Daniel Borkmann
2018-05-15 2:18 ` Y Song
2018-05-15 2:19 ` [PATCH bpf-next v2 0/8] Minor follow-up cleanups in BPF JITs and optimized imm emission Alexei Starovoitov
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