From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id D39EF347503; Wed, 8 Apr 2026 18:12:23 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775671943; cv=none; b=Ji/r8r9uNAAj0iLhThm6dgumIvBGhyqOVrXlIBD7OypVIfcvYh4uFDLcRfM8Fsv71pOfInb8QzXmd8zOS7TQdSut6TBP1tssKSiMkmy9XZzblGWEQ8iAgW7NsfOKY9tTv2lQIzU0vkbpTWpSVP6//WVMB9XJIWcblm8dVjGRQfY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775671943; c=relaxed/simple; bh=okhoLLdnlsL7B8GcEu3ImMBk4ButMhx0LFSv2qVM2k0=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=I2rwz/wXn1sx/LF5iQjhQgtXQU+i3wYRyBFp+/Q0SjxwssWGV6xO9jTp8Qosm4pj7lAGnMnuQjr5xIH+Vw0KChRBgZ61DYVKiXkZF59FOnqG4Ea87ebn737G1jHUejk1FXbIugv3AjBFxZPJe7kvfsKKuWUSytRdlQjPbIoFd2w= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=p8tHCUBl; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="p8tHCUBl" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 619FDC19421; Wed, 8 Apr 2026 18:12:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1775671943; bh=okhoLLdnlsL7B8GcEu3ImMBk4ButMhx0LFSv2qVM2k0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=p8tHCUBlMXYCNMfHajJEYmDLoNqYW1TM/Hovq+lLFM6jOKWVKVOF17DTxeIeus0XX EN2dcC9fpnzeXONeUs8jaiLUynwSpAQj8hVeZIf+C5QfyfQWrg05J6CAB+jsFIqo4F QhpxkGLe9lQnPgP9+oH6M5K7l9DxQNdkXosGt59U= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Venkat Rao Bagalkote , Hari Bathini , Madhavan Srinivasan Subject: [PATCH 6.1 121/312] powerpc64/bpf: do not increment tailcall count when prog is NULL Date: Wed, 8 Apr 2026 20:00:38 +0200 Message-ID: <20260408175938.288123609@linuxfoundation.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260408175933.715315542@linuxfoundation.org> References: <20260408175933.715315542@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.1-stable review patch. If anyone has any objections, please let me know. ------------------ From: Hari Bathini commit 521bd39d9d28ce54cbfec7f9b89c94ad4fdb8350 upstream. Do not increment tailcall count, if tailcall did not succeed due to missing BPF program. Fixes: ce0761419fae ("powerpc/bpf: Implement support for tail calls") Cc: stable@vger.kernel.org Tested-by: Venkat Rao Bagalkote Signed-off-by: Hari Bathini Signed-off-by: Madhavan Srinivasan Link: https://patch.msgid.link/20260303181031.390073-2-hbathini@linux.ibm.com [ Conflict due to missing feature commit 2ed2d8f6fb38 ("powerpc64/bpf: Support tailcalls with subprogs") resolved accordingly. ] Signed-off-by: Hari Bathini Signed-off-by: Greg Kroah-Hartman --- arch/powerpc/net/bpf_jit_comp64.c | 23 ++++++++++++++--------- 1 file changed, 14 insertions(+), 9 deletions(-) --- a/arch/powerpc/net/bpf_jit_comp64.c +++ b/arch/powerpc/net/bpf_jit_comp64.c @@ -288,27 +288,32 @@ static int bpf_jit_emit_tail_call(u32 *i /* * tail_call_cnt++; + * Writeback this updated value only if tailcall succeeds. */ EMIT(PPC_RAW_ADDI(bpf_to_ppc(TMP_REG_1), bpf_to_ppc(TMP_REG_1), 1)); - EMIT(PPC_RAW_STD(bpf_to_ppc(TMP_REG_1), _R1, bpf_jit_stack_tailcallcnt(ctx))); /* prog = array->ptrs[index]; */ - EMIT(PPC_RAW_MULI(bpf_to_ppc(TMP_REG_1), b2p_index, 8)); - EMIT(PPC_RAW_ADD(bpf_to_ppc(TMP_REG_1), bpf_to_ppc(TMP_REG_1), b2p_bpf_array)); - EMIT(PPC_RAW_LD(bpf_to_ppc(TMP_REG_1), bpf_to_ppc(TMP_REG_1), offsetof(struct bpf_array, ptrs))); + EMIT(PPC_RAW_MULI(bpf_to_ppc(TMP_REG_2), b2p_index, 8)); + EMIT(PPC_RAW_ADD(bpf_to_ppc(TMP_REG_2), bpf_to_ppc(TMP_REG_2), b2p_bpf_array)); + EMIT(PPC_RAW_LD(bpf_to_ppc(TMP_REG_2), bpf_to_ppc(TMP_REG_2), + offsetof(struct bpf_array, ptrs))); /* * if (prog == NULL) * goto out; */ - EMIT(PPC_RAW_CMPLDI(bpf_to_ppc(TMP_REG_1), 0)); + EMIT(PPC_RAW_CMPLDI(bpf_to_ppc(TMP_REG_2), 0)); PPC_BCC_SHORT(COND_EQ, out); /* goto *(prog->bpf_func + prologue_size); */ - EMIT(PPC_RAW_LD(bpf_to_ppc(TMP_REG_1), bpf_to_ppc(TMP_REG_1), offsetof(struct bpf_prog, bpf_func))); - EMIT(PPC_RAW_ADDI(bpf_to_ppc(TMP_REG_1), bpf_to_ppc(TMP_REG_1), - FUNCTION_DESCR_SIZE + bpf_tailcall_prologue_size)); - EMIT(PPC_RAW_MTCTR(bpf_to_ppc(TMP_REG_1))); + EMIT(PPC_RAW_LD(bpf_to_ppc(TMP_REG_2), bpf_to_ppc(TMP_REG_2), + offsetof(struct bpf_prog, bpf_func))); + EMIT(PPC_RAW_ADDI(bpf_to_ppc(TMP_REG_2), bpf_to_ppc(TMP_REG_2), + FUNCTION_DESCR_SIZE + bpf_tailcall_prologue_size)); + EMIT(PPC_RAW_MTCTR(bpf_to_ppc(TMP_REG_2))); + + /* Writeback updated tailcall count */ + EMIT(PPC_RAW_STD(bpf_to_ppc(TMP_REG_1), _R1, bpf_jit_stack_tailcallcnt(ctx))); /* tear down stack, restore NVRs, ... */ bpf_jit_emit_common_epilogue(image, ctx);