Netdev Archive on lore.kernel.org
 help / color / Atom feed
From: Josh Poimboeuf <jpoimboe@redhat.com>
To: x86@kernel.org, Alexei Starovoitov <ast@kernel.org>
Cc: linux-kernel@vger.kernel.org,
	Daniel Borkmann <daniel@iogearbox.net>,
	netdev@vger.kernel.org, bpf@vger.kernel.org,
	Peter Zijlstra <peterz@infradead.org>,
	Song Liu <songliubraving@fb.com>, Kairui Song <kasong@redhat.com>,
	Steven Rostedt <rostedt@goodmis.org>,
	David Laight <David.Laight@ACULAB.COM>,
	Thomas Gleixner <tglx@linutronix.de>,
	Borislav Petkov <bp@alien8.de>, Ingo Molnar <mingo@kernel.org>
Subject: [PATCH v2 3/5] x86/bpf: Move epilogue generation to a dedicated function
Date: Fri, 14 Jun 2019 12:56:42 -0500
Message-ID: <950a6d53bb000ca4cdd946ec6cfd1570c77c2df5.1560534694.git.jpoimboe@redhat.com> (raw)
In-Reply-To: <cover.1560534694.git.jpoimboe@redhat.com>

Improve code readability by moving the BPF JIT function epilogue
generation code to a dedicated emit_epilogue() function, analagous to
the existing emit_prologue() function.

Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
---
 arch/x86/net/bpf_jit_comp.c | 37 ++++++++++++++++++++++++-------------
 1 file changed, 24 insertions(+), 13 deletions(-)

diff --git a/arch/x86/net/bpf_jit_comp.c b/arch/x86/net/bpf_jit_comp.c
index 32bfab4e21eb..da8c988b0f0f 100644
--- a/arch/x86/net/bpf_jit_comp.c
+++ b/arch/x86/net/bpf_jit_comp.c
@@ -240,6 +240,28 @@ static void emit_prologue(u8 **pprog, u32 stack_depth, bool ebpf_from_cbpf)
 	*pprog = prog;
 }
 
+static void emit_epilogue(u8 **pprog)
+{
+	u8 *prog = *pprog;
+	int cnt = 0;
+
+	/* mov rbx, qword ptr [rbp+0] */
+	EMIT4(0x48, 0x8B, 0x5D, 0);
+	/* mov r13, qword ptr [rbp+8] */
+	EMIT4(0x4C, 0x8B, 0x6D, 8);
+	/* mov r14, qword ptr [rbp+16] */
+	EMIT4(0x4C, 0x8B, 0x75, 16);
+	/* mov r15, qword ptr [rbp+24] */
+	EMIT4(0x4C, 0x8B, 0x7D, 24);
+
+	/* add rbp, AUX_STACK_SPACE */
+	EMIT4(0x48, 0x83, 0xC5, AUX_STACK_SPACE);
+	EMIT1(0xC9); /* leave */
+	EMIT1(0xC3); /* ret */
+
+	*pprog = prog;
+}
+
 /*
  * Generate the following code:
  *
@@ -1036,19 +1058,8 @@ xadd:			if (is_imm8(insn->off))
 			seen_exit = true;
 			/* Update cleanup_addr */
 			ctx->cleanup_addr = proglen;
-			/* mov rbx, qword ptr [rbp+0] */
-			EMIT4(0x48, 0x8B, 0x5D, 0);
-			/* mov r13, qword ptr [rbp+8] */
-			EMIT4(0x4C, 0x8B, 0x6D, 8);
-			/* mov r14, qword ptr [rbp+16] */
-			EMIT4(0x4C, 0x8B, 0x75, 16);
-			/* mov r15, qword ptr [rbp+24] */
-			EMIT4(0x4C, 0x8B, 0x7D, 24);
-
-			/* add rbp, AUX_STACK_SPACE */
-			EMIT4(0x48, 0x83, 0xC5, AUX_STACK_SPACE);
-			EMIT1(0xC9); /* leave */
-			EMIT1(0xC3); /* ret */
+
+			emit_epilogue(&prog);
 			break;
 
 		default:
-- 
2.20.1


  parent reply index

Thread overview: 31+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-06-14 17:56 [PATCH v2 0/5] x86/bpf: unwinder fixes Josh Poimboeuf
2019-06-14 17:56 ` [PATCH v2 1/5] perf/x86: Always store regs->ip in perf_callchain_kernel() Josh Poimboeuf
2019-06-14 20:56   ` Alexei Starovoitov
2019-06-14 21:06     ` Josh Poimboeuf
2019-06-14 21:16       ` Steven Rostedt
2019-06-14 21:20         ` Song Liu
2019-06-14 17:56 ` [PATCH v2 2/5] objtool: Fix ORC unwinding in non-JIT BPF generated code Josh Poimboeuf
2019-06-14 20:58   ` Alexei Starovoitov
2019-06-14 21:07     ` Josh Poimboeuf
2019-06-14 21:09       ` Alexei Starovoitov
2019-06-14 21:19         ` Josh Poimboeuf
2019-06-14 21:22           ` Alexei Starovoitov
2019-06-14 23:17             ` Josh Poimboeuf
2019-06-14 23:30               ` Alexei Starovoitov
2019-06-15  0:02                 ` Josh Poimboeuf
2019-06-15  0:06                   ` abhja kaanlani
2019-06-15  0:07                   ` Alexei Starovoitov
2019-06-17 14:57     ` David Laight
2019-06-14 17:56 ` Josh Poimboeuf [this message]
2019-06-14 17:56 ` [PATCH v2 4/5] x86/bpf: Fix 64-bit JIT frame pointer usage Josh Poimboeuf
2019-06-14 21:05   ` Alexei Starovoitov
2019-06-14 21:19     ` Josh Poimboeuf
2019-06-14 21:27       ` Alexei Starovoitov
2019-06-14 23:13         ` Josh Poimboeuf
2019-06-14 23:23           ` Alexei Starovoitov
2019-06-14 23:54             ` Josh Poimboeuf
2019-06-15  0:02               ` Alexei Starovoitov
2019-06-15  4:27                 ` Josh Poimboeuf
2019-06-15  5:16                   ` Alexei Starovoitov
2019-06-15 12:57                     ` Josh Poimboeuf
2019-06-14 17:56 ` [PATCH v2 5/5] x86/unwind/orc: Fall back to using frame pointers for generated code Josh Poimboeuf

Reply instructions:

You may reply publically to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=950a6d53bb000ca4cdd946ec6cfd1570c77c2df5.1560534694.git.jpoimboe@redhat.com \
    --to=jpoimboe@redhat.com \
    --cc=David.Laight@ACULAB.COM \
    --cc=ast@kernel.org \
    --cc=bp@alien8.de \
    --cc=bpf@vger.kernel.org \
    --cc=daniel@iogearbox.net \
    --cc=kasong@redhat.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mingo@kernel.org \
    --cc=netdev@vger.kernel.org \
    --cc=peterz@infradead.org \
    --cc=rostedt@goodmis.org \
    --cc=songliubraving@fb.com \
    --cc=tglx@linutronix.de \
    --cc=x86@kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

Netdev Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/netdev/0 netdev/git/0.git
	git clone --mirror https://lore.kernel.org/netdev/1 netdev/git/1.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 netdev netdev/ https://lore.kernel.org/netdev \
		netdev@vger.kernel.org netdev@archiver.kernel.org
	public-inbox-index netdev


Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.kernel.vger.netdev


AGPL code for this site: git clone https://public-inbox.org/ public-inbox