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From: Christophe Leroy <christophe.leroy@csgroup.eu>
To: Michael Ellerman <mpe@ellerman.id.au>,
	Nicholas Piggin <npiggin@gmail.com>,
	"Naveen N. Rao" <naveen.n.rao@linux.ibm.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>,
	linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org,
	bpf@vger.kernel.org, Alexei Starovoitov <ast@kernel.org>,
	Daniel Borkmann <daniel@iogearbox.net>,
	Andrii Nakryiko <andrii@kernel.org>,
	Martin KaFai Lau <martin.lau@linux.dev>,
	Song Liu <song@kernel.org>, Yonghong Song <yhs@fb.com>,
	John Fastabend <john.fastabend@gmail.com>,
	KP Singh <kpsingh@kernel.org>,
	Stanislav Fomichev <sdf@google.com>, Hao Luo <haoluo@google.com>,
	Jiri Olsa <jolsa@kernel.org>
Subject: [PATCH v2 4/9] powerpc/bpf/32: BPF prog is never called with more than one arg
Date: Wed,  1 Feb 2023 11:04:26 +0100	[thread overview]
Message-ID: <89a200fb45048601475c092c5775294dee3886de.1675245773.git.christophe.leroy@csgroup.eu> (raw)
In-Reply-To: <4fd69ef7945518c3e27f96b95046a5c1468d35bf.1675245773.git.christophe.leroy@csgroup.eu>

BPF progs are never called with more than one argument, plus the
tail call count as a second argument when needed.

So, no need to retrieve 9th and 10th argument (5th 64 bits argument)
from the stack in prologue.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/net/bpf_jit_comp32.c | 6 ------
 1 file changed, 6 deletions(-)

diff --git a/arch/powerpc/net/bpf_jit_comp32.c b/arch/powerpc/net/bpf_jit_comp32.c
index 7f54d37bede6..7c129fe810f5 100644
--- a/arch/powerpc/net/bpf_jit_comp32.c
+++ b/arch/powerpc/net/bpf_jit_comp32.c
@@ -159,12 +159,6 @@ void bpf_jit_build_prologue(u32 *image, struct codegen_context *ctx)
 		if (bpf_is_seen_register(ctx, i))
 			EMIT(PPC_RAW_STW(i, _R1, bpf_jit_stack_offsetof(ctx, i)));
 
-	/* If needed retrieve arguments 9 and 10, ie 5th 64 bits arg.*/
-	if (bpf_is_seen_register(ctx, bpf_to_ppc(BPF_REG_5))) {
-		EMIT(PPC_RAW_LWZ(bpf_to_ppc(BPF_REG_5) - 1, _R1, BPF_PPC_STACKFRAME(ctx)) + 8);
-		EMIT(PPC_RAW_LWZ(bpf_to_ppc(BPF_REG_5), _R1, BPF_PPC_STACKFRAME(ctx)) + 12);
-	}
-
 	/* Setup frame pointer to point to the bpf stack area */
 	if (bpf_is_seen_register(ctx, bpf_to_ppc(BPF_REG_FP))) {
 		EMIT(PPC_RAW_LI(bpf_to_ppc(BPF_REG_FP) - 1, 0));
-- 
2.39.1


WARNING: multiple messages have this Message-ID (diff)
From: Christophe Leroy <christophe.leroy@csgroup.eu>
To: Michael Ellerman <mpe@ellerman.id.au>,
	Nicholas Piggin <npiggin@gmail.com>,
	"Naveen N. Rao" <naveen.n.rao@linux.ibm.com>
Cc: Hao Luo <haoluo@google.com>,
	Daniel Borkmann <daniel@iogearbox.net>,
	Song Liu <song@kernel.org>,
	Martin KaFai Lau <martin.lau@linux.dev>,
	John Fastabend <john.fastabend@gmail.com>,
	linux-kernel@vger.kernel.org, Alexei Starovoitov <ast@kernel.org>,
	Andrii Nakryiko <andrii@kernel.org>,
	Stanislav Fomichev <sdf@google.com>, Jiri Olsa <jolsa@kernel.org>,
	KP Singh <kpsingh@kernel.org>, Yonghong Song <yhs@fb.com>,
	bpf@vger.kernel.org, linuxppc-dev@lists.ozlabs.org
Subject: [PATCH v2 4/9] powerpc/bpf/32: BPF prog is never called with more than one arg
Date: Wed,  1 Feb 2023 11:04:26 +0100	[thread overview]
Message-ID: <89a200fb45048601475c092c5775294dee3886de.1675245773.git.christophe.leroy@csgroup.eu> (raw)
In-Reply-To: <4fd69ef7945518c3e27f96b95046a5c1468d35bf.1675245773.git.christophe.leroy@csgroup.eu>

BPF progs are never called with more than one argument, plus the
tail call count as a second argument when needed.

So, no need to retrieve 9th and 10th argument (5th 64 bits argument)
from the stack in prologue.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/net/bpf_jit_comp32.c | 6 ------
 1 file changed, 6 deletions(-)

diff --git a/arch/powerpc/net/bpf_jit_comp32.c b/arch/powerpc/net/bpf_jit_comp32.c
index 7f54d37bede6..7c129fe810f5 100644
--- a/arch/powerpc/net/bpf_jit_comp32.c
+++ b/arch/powerpc/net/bpf_jit_comp32.c
@@ -159,12 +159,6 @@ void bpf_jit_build_prologue(u32 *image, struct codegen_context *ctx)
 		if (bpf_is_seen_register(ctx, i))
 			EMIT(PPC_RAW_STW(i, _R1, bpf_jit_stack_offsetof(ctx, i)));
 
-	/* If needed retrieve arguments 9 and 10, ie 5th 64 bits arg.*/
-	if (bpf_is_seen_register(ctx, bpf_to_ppc(BPF_REG_5))) {
-		EMIT(PPC_RAW_LWZ(bpf_to_ppc(BPF_REG_5) - 1, _R1, BPF_PPC_STACKFRAME(ctx)) + 8);
-		EMIT(PPC_RAW_LWZ(bpf_to_ppc(BPF_REG_5), _R1, BPF_PPC_STACKFRAME(ctx)) + 12);
-	}
-
 	/* Setup frame pointer to point to the bpf stack area */
 	if (bpf_is_seen_register(ctx, bpf_to_ppc(BPF_REG_FP))) {
 		EMIT(PPC_RAW_LI(bpf_to_ppc(BPF_REG_FP) - 1, 0));
-- 
2.39.1


  parent reply	other threads:[~2023-02-01 10:06 UTC|newest]

Thread overview: 20+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-02-01 10:04 [PATCH v2 1/9] powerpc: Remove __kernel_text_address() in show_instructions() Christophe Leroy
2023-02-01 10:04 ` Christophe Leroy
2023-02-01 10:04 ` [PATCH v2 2/9] powerpc/bpf/32: No need to zeroise r4 when not doing tail call Christophe Leroy
2023-02-01 10:04   ` Christophe Leroy
2023-02-01 10:04 ` [PATCH v2 3/9] powerpc/bpf/32: Only set a stack frame when necessary Christophe Leroy
2023-02-01 10:04   ` Christophe Leroy
2023-02-01 10:04 ` Christophe Leroy [this message]
2023-02-01 10:04   ` [PATCH v2 4/9] powerpc/bpf/32: BPF prog is never called with more than one arg Christophe Leroy
2023-02-01 10:04 ` [PATCH v2 5/9] powerpc/bpf: Perform complete extra passes to update addresses Christophe Leroy
2023-02-01 10:04   ` Christophe Leroy
2023-02-01 10:04 ` [PATCH v2 6/9] powerpc/bpf: Only pad length-variable code at initial pass Christophe Leroy
2023-02-01 10:04   ` Christophe Leroy
2023-02-01 10:04 ` [PATCH v2 7/9] powerpc/bpf/32: Optimise some particular const operations Christophe Leroy
2023-02-01 10:04   ` Christophe Leroy
2023-02-01 10:04 ` [PATCH v2 8/9] powerpc/bpf/32: introduce a second source register for ALU operations Christophe Leroy
2023-02-01 10:04   ` Christophe Leroy
2023-02-01 10:04 ` [PATCH v2 9/9] powerpc/bpf/32: perform three operands " Christophe Leroy
2023-02-01 10:04   ` Christophe Leroy
2023-02-15 12:40 ` [PATCH v2 1/9] powerpc: Remove __kernel_text_address() in show_instructions() Michael Ellerman
2023-02-15 12:40   ` Michael Ellerman

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