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From: "Naveen N. Rao" <naveen.n.rao@linux.vnet.ibm.com>
To: Michael Ellerman <mpe@ellerman.id.au>,
	Daniel Borkmann <daniel@iogearbox.net>,
	Alexei Starovoitov <alexei.starovoitov@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>,
	ykaliuta@redhat.com,
	Christophe Leroy <christophe.leroy@csgroup.eu>,
	song@kernel.org, johan.almbladh@anyfinetworks.com,
	Hari Bathini <hbathini@linux.ibm.com>, <bpf@vger.kernel.org>,
	<linuxppc-dev@lists.ozlabs.org>
Subject: [PATCH 02/13] powerpc32/bpf: Fix codegen for bpf-to-bpf calls
Date: Thu,  6 Jan 2022 17:15:06 +0530	[thread overview]
Message-ID: <52d8fe51f7620a6f27f377791564d79d75463576.1641468127.git.naveen.n.rao@linux.vnet.ibm.com> (raw)
In-Reply-To: <cover.1641468127.git.naveen.n.rao@linux.vnet.ibm.com>

Pad instructions emitted for BPF_CALL so that the number of instructions
generated does not change for different function addresses. This is
especially important for calls to other bpf functions, whose address
will only be known during extra pass.

Fixes: 51c66ad849a703 ("powerpc/bpf: Implement extended BPF on PPC32")
Cc: stable@vger.kernel.org # v5.13+
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
---
 arch/powerpc/net/bpf_jit_comp32.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/arch/powerpc/net/bpf_jit_comp32.c b/arch/powerpc/net/bpf_jit_comp32.c
index d3a52cd42f5346..997a47fa615b30 100644
--- a/arch/powerpc/net/bpf_jit_comp32.c
+++ b/arch/powerpc/net/bpf_jit_comp32.c
@@ -191,6 +191,9 @@ void bpf_jit_emit_func_call_rel(u32 *image, struct codegen_context *ctx, u64 fun
 
 	if (image && rel < 0x2000000 && rel >= -0x2000000) {
 		PPC_BL_ABS(func);
+		EMIT(PPC_RAW_NOP());
+		EMIT(PPC_RAW_NOP());
+		EMIT(PPC_RAW_NOP());
 	} else {
 		/* Load function address into r0 */
 		EMIT(PPC_RAW_LIS(_R0, IMM_H(func)));
-- 
2.34.1


WARNING: multiple messages have this Message-ID (diff)
From: "Naveen N. Rao" <naveen.n.rao@linux.vnet.ibm.com>
To: Michael Ellerman <mpe@ellerman.id.au>,
	Daniel Borkmann <daniel@iogearbox.net>,
	Alexei Starovoitov <alexei.starovoitov@gmail.com>
Cc: ykaliuta@redhat.com, johan.almbladh@anyfinetworks.com,
	linuxppc-dev@lists.ozlabs.org, song@kernel.org,
	bpf@vger.kernel.org, Jiri Olsa <jolsa@redhat.com>,
	Hari Bathini <hbathini@linux.ibm.com>
Subject: [PATCH 02/13] powerpc32/bpf: Fix codegen for bpf-to-bpf calls
Date: Thu,  6 Jan 2022 17:15:06 +0530	[thread overview]
Message-ID: <52d8fe51f7620a6f27f377791564d79d75463576.1641468127.git.naveen.n.rao@linux.vnet.ibm.com> (raw)
In-Reply-To: <cover.1641468127.git.naveen.n.rao@linux.vnet.ibm.com>

Pad instructions emitted for BPF_CALL so that the number of instructions
generated does not change for different function addresses. This is
especially important for calls to other bpf functions, whose address
will only be known during extra pass.

Fixes: 51c66ad849a703 ("powerpc/bpf: Implement extended BPF on PPC32")
Cc: stable@vger.kernel.org # v5.13+
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
---
 arch/powerpc/net/bpf_jit_comp32.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/arch/powerpc/net/bpf_jit_comp32.c b/arch/powerpc/net/bpf_jit_comp32.c
index d3a52cd42f5346..997a47fa615b30 100644
--- a/arch/powerpc/net/bpf_jit_comp32.c
+++ b/arch/powerpc/net/bpf_jit_comp32.c
@@ -191,6 +191,9 @@ void bpf_jit_emit_func_call_rel(u32 *image, struct codegen_context *ctx, u64 fun
 
 	if (image && rel < 0x2000000 && rel >= -0x2000000) {
 		PPC_BL_ABS(func);
+		EMIT(PPC_RAW_NOP());
+		EMIT(PPC_RAW_NOP());
+		EMIT(PPC_RAW_NOP());
 	} else {
 		/* Load function address into r0 */
 		EMIT(PPC_RAW_LIS(_R0, IMM_H(func)));
-- 
2.34.1


  parent reply	other threads:[~2022-01-06 11:46 UTC|newest]

Thread overview: 65+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-01-06 11:45 [PATCH 00/13] powerpc/bpf: Some fixes and updates Naveen N. Rao
2022-01-06 11:45 ` Naveen N. Rao
2022-01-06 11:45 ` [PATCH 01/13] bpf: Guard against accessing NULL pt_regs in bpf_get_task_stack() Naveen N. Rao
2022-01-06 11:45   ` Naveen N. Rao
2022-01-07 10:21   ` Daniel Borkmann
2022-01-07 10:21     ` Daniel Borkmann
2022-01-10  8:57   ` Christophe Leroy
2022-01-10  8:57     ` Christophe Leroy
2022-01-10 10:36     ` Naveen N. Rao
2022-01-10 10:36       ` Naveen N. Rao
2022-01-06 11:45 ` Naveen N. Rao [this message]
2022-01-06 11:45   ` [PATCH 02/13] powerpc32/bpf: Fix codegen for bpf-to-bpf calls Naveen N. Rao
2022-01-10  9:06   ` Christophe Leroy
2022-01-10  9:06     ` Christophe Leroy
2022-01-10 10:52     ` Naveen N. Rao
2022-01-10 10:52       ` Naveen N. Rao
2022-01-06 11:45 ` [PATCH 03/13] powerpc/bpf: Update ldimm64 instructions during extra pass Naveen N. Rao
2022-01-06 11:45   ` Naveen N. Rao
2022-01-08 14:45   ` Jiri Olsa
2022-01-08 14:45     ` Jiri Olsa
2022-01-10  9:27   ` Christophe Leroy
2022-01-10  9:27     ` Christophe Leroy
2022-01-10 10:56     ` Naveen N. Rao
2022-01-10 10:56       ` Naveen N. Rao
2022-01-06 11:45 ` [PATCH 04/13] tools/bpf: Rename 'struct event' to avoid naming conflict Naveen N. Rao
2022-01-06 11:45   ` Naveen N. Rao
2022-01-07 10:21   ` Daniel Borkmann
2022-01-07 10:21     ` Daniel Borkmann
2022-01-06 11:45 ` [PATCH 05/13] powerpc/bpf: Skip branch range validation during first pass Naveen N. Rao
2022-01-06 11:45   ` Naveen N. Rao
2022-01-06 11:45 ` [PATCH 06/13] powerpc/bpf: Emit a single branch instruction for known short branch ranges Naveen N. Rao
2022-01-06 11:45   ` Naveen N. Rao
2022-01-06 11:45 ` [PATCH 07/13] powerpc/bpf: Handle large branch ranges with BPF_EXIT Naveen N. Rao
2022-01-06 11:45   ` Naveen N. Rao
2022-01-06 11:45 ` [PATCH 08/13] powerpc64/bpf: Limit 'ldbrx' to processors compliant with ISA v2.06 Naveen N. Rao
2022-01-06 11:45   ` Naveen N. Rao
2022-01-06 11:45 ` [PATCH 09/13] powerpc64/bpf: Do not save/restore LR on each call to bpf_stf_barrier() Naveen N. Rao
2022-01-06 11:45   ` Naveen N. Rao
2022-01-06 11:45 ` [PATCH 10/13] powerpc64/bpf: Use r12 for constant blinding Naveen N. Rao
2022-01-06 11:45   ` Naveen N. Rao
2022-01-06 11:45 ` [PATCH 11/13] powerpc64/bpf elfv2: Setup kernel TOC in r2 on entry Naveen N. Rao
2022-01-06 11:45   ` Naveen N. Rao
2022-01-10  9:20   ` Christophe Leroy
2022-01-10  9:20     ` Christophe Leroy
2022-01-11 10:31     ` Naveen N. Rao
2022-01-11 10:31       ` Naveen N. Rao
2022-01-11 14:35       ` Christophe Leroy
2022-01-11 14:35         ` Christophe Leroy
2022-01-11 14:43         ` Christophe Leroy
2022-01-14 11:17           ` Naveen N. Rao
2022-01-14 11:17             ` Naveen N. Rao
2022-01-06 11:45 ` [PATCH 12/13] powerpc64/bpf elfv1: Do not load TOC before calling functions Naveen N. Rao
2022-01-06 11:45   ` Naveen N. Rao
2022-01-06 11:45 ` [PATCH 13/13] powerpc64/bpf: Optimize instruction sequence used for function calls Naveen N. Rao
2022-01-06 11:45   ` Naveen N. Rao
2022-01-06 21:46 ` [PATCH 00/13] powerpc/bpf: Some fixes and updates Daniel Borkmann
2022-01-06 21:46   ` Daniel Borkmann
2022-01-07  7:36   ` Naveen N. Rao
2022-01-07  7:36     ` Naveen N. Rao
2022-01-07 10:20     ` Daniel Borkmann
2022-01-07 10:20       ` Daniel Borkmann
2022-01-10  3:47       ` Michael Ellerman
2022-01-10  3:47         ` Michael Ellerman
2022-01-16 10:41 ` Michael Ellerman
2022-01-16 10:41   ` Michael Ellerman

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