From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1794064282; b=uQxPL8BD8ek+zG9guTVQAU+L1KeW1r4kMptaO5R+tItP9r62owpa9HshICXjxXxql45j 4q4CRobayLMdk2JhtVekFEhknnA+x0L5AmPgZqjLAOcghbpTGTQWHXlAVRfb7+YvmUgoX NrAsJXwLzGizM+B/FltNXtuSlREucmwthTT7Yw/w1ab8asXCKOWC8aqxmlbZzSyc7o1qy UbcLYR0byafMSIr/i37YkGPI/ZI6264P1CEArFfPtS2e4jBHFacDcrjxzlXNKikT/q7FP 11ALmLm0fUCI4ePrgrz+ut1CwJrsWyCK8J/TTFFzm+F5BeFm5d/LVMkgDgBoC0EsO5A== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794064282; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:User-Agent:X-stable:X-Patchwork-Hint: MIME-Version:Content-Transfer-Encoding; bh=pyWEjxmqEItsoGFZVDNkOTDykrxWEk8I08oiKlTDZIs=; b=0ecfkt9Z28InufP0qFSmCWTlbQdv4r1XuV8fJS2o6hujvWGHN49Fa1/gMe+j0cPnQfxX DtqqLR58RXWYlY2mzIp3iDZEZ3O3Qg09sDcJoFiTt1DrR/VMvxtQ7eT1y5GNRcGCb6bp+ 3c+YjvhI/+liyYZcrVENXn0NboI72PwQ9ZG7gnPZhgpQK/xABIJ1ysAeTCufKXb6RbjvG R+1v/He3nCqtxH35F9SnQtNPA2DEjbS8HqsFtuM4eIycCRmwWmwyDTjMQd9GnxdGxIx9P muV+eV2BBzv/pSv6/G9sE8UMNnrCjGEAVP+eY2Vjy4+hM2k1QY9OmpK4/6BH5Clh5HA== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=he19pHrD; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 038796082BFF; Sat, 7 Nov 2026 15:11:22 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=he19pHrD Received: by smtp.kernel.org (Postfix) with ESMTPSA id AC3F41F008A1; Sat, 7 Nov 2026 15:11:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1794064281; bh=pyWEjxmqEItsoGFZVDNkOTDykrxWEk8I08oiKlTDZIs=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=he19pHrDJZPuRfONOijutSx97RSRGjLbFgZCCMQChop7mZHgbjIW5e6LpTDYfCOPz mHXo1n3J0dx51bz4IYSck4L/X4s+EjqQbIV6KczLMUuw015h34P/2ZQfUjLpCKcj2Z p6sJfeIq0L2uzqR0P7EHMel6oQz81/PA25gHGvwc= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Hari Bathini , Abhishek Dubey , Saket Kumar Bhaskar , Yeswanth Krishna Tellakula , R Nageswara Sastry , Madhavan Srinivasan , Sasha Levin Subject: [PATCH 7.3 0375/1257] powerpc/bpf: fix alignment of long branch trampoline address Date: Sat, 7 Nov 2026 08:44:31 -0500 Message-ID: <20261107134949.911435575@linuxfoundation.org> X-Mailer: git-send-email 2.56.0 In-Reply-To: <20261107134939.434104957@linuxfoundation.org> References: <20261107134939.434104957@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore X-Mailing-List: stable@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 7.3-stable review patch. If anyone has any objections, please let me know. ------------------ From: Abhishek Dubey [ Upstream commit 04001e8ddb979f463f1c3ca8ac4d6ac59fb48921 ] Ensure the dummy trampoline address field present between the OOL stub and the long branch stub is 4/8-byte aligned, for memory compatibility when content loaded to a register. Reported-by: Hari Bathini Fixes: d243b62b7bd3 ("powerpc64/bpf: Add support for bpf trampolines") Cc: stable@vger.kernel.org Signed-off-by: Abhishek Dubey Signed-off-by: Saket Kumar Bhaskar Tested-by: Yeswanth Krishna Tellakula Tested-by: R Nageswara Sastry Reviewed-by: Hari Bathini Signed-off-by: Madhavan Srinivasan Link: https://patch.msgid.link/a8257022057cbb71928c960be589e10b89fc0899.1789982239.git.skb99@linux.ibm.com Signed-off-by: Sasha Levin --- arch/powerpc/net/bpf_jit.h | 7 +++--- arch/powerpc/net/bpf_jit_comp.c | 38 ++++++++++++++++++++++++++----- arch/powerpc/net/bpf_jit_comp32.c | 7 +++--- arch/powerpc/net/bpf_jit_comp64.c | 7 +++--- 4 files changed, 44 insertions(+), 15 deletions(-) diff --git a/arch/powerpc/net/bpf_jit.h b/arch/powerpc/net/bpf_jit.h index 995308654a569..44fa414dc5a76 100644 --- a/arch/powerpc/net/bpf_jit.h +++ b/arch/powerpc/net/bpf_jit.h @@ -221,10 +221,11 @@ int bpf_jit_emit_func_call_rel(u32 *image, u32 *fimage, struct codegen_context * int bpf_jit_build_body(struct bpf_prog *fp, u32 *image, u32 *fimage, struct codegen_context *ctx, u32 *addrs, int pass, bool extra_pass); void bpf_jit_build_prologue(u32 *image, struct codegen_context *ctx); -void bpf_jit_build_epilogue(u32 *image, struct codegen_context *ctx); -void bpf_jit_build_fentry_stubs(u32 *image, struct codegen_context *ctx); +void bpf_jit_build_epilogue(u32 *image, u32 *fimage, struct codegen_context *ctx); +void bpf_jit_build_fentry_stubs(u32 *image, u32 *fimage, struct codegen_context *ctx); void bpf_jit_realloc_regs(struct codegen_context *ctx); -int bpf_jit_emit_exit_insn(u32 *image, struct codegen_context *ctx, int tmp_reg, long exit_addr); +int bpf_jit_emit_exit_insn(u32 *image, u32 *fimage, struct codegen_context *ctx, int tmp_reg, + long exit_addr); void prepare_for_fsession_fentry(u32 *image, struct codegen_context *ctx, int cookie_cnt, int cookie_off, int retval_off); void store_func_meta(u32 *image, struct codegen_context *ctx, u64 func_meta, int func_meta_off); diff --git a/arch/powerpc/net/bpf_jit_comp.c b/arch/powerpc/net/bpf_jit_comp.c index 0c277a11b641e..1272409336120 100644 --- a/arch/powerpc/net/bpf_jit_comp.c +++ b/arch/powerpc/net/bpf_jit_comp.c @@ -49,11 +49,35 @@ asm ( " .popsection ;" ); -void bpf_jit_build_fentry_stubs(u32 *image, struct codegen_context *ctx) +void bpf_jit_build_fentry_stubs(u32 *image, u32 *fimage, struct codegen_context *ctx) { int ool_stub_idx, long_branch_stub_idx; + int ool_stub_sz; /* + * Align the mis-aligned dummy_tramp_addr field in the fimage. + * The alignment NOP must appear before OOL stub, to make + * ool_stub_idx & long_branch_stub_idx constant from end. + * + * The fimage can be non 8-byte aligned, so final alignment depends + * on start of fimage and the stub's instruction count offset. The + * OOL stub size is 4 instructions (with CONFIG_PPC_FTRACE_OUT_OF_LINE) + * or 3 instructions (without) before dummy_tramp_addr. + * + * Emit a NOP here if address is not SZL aligned. + * + * In pass=0 when image==NULL, conservatively account for space + * required to accommodate alignment NOP. In case final pass skips + * emitting alignment NOP, the image buffer have 4 spare bytes and + * jited_len signifies correct program size. + */ + + ool_stub_sz = IS_ENABLED(CONFIG_PPC_FTRACE_OUT_OF_LINE) ? 16 : 12; + if (!image || !IS_ALIGNED((unsigned long)fimage + ctx->idx*4 + ool_stub_sz, SZL)) + EMIT(PPC_RAW_NOP()); + + /* + * nop // optional, for alignment of dummy_tramp_addr * Out-of-line stub: * mflr r0 * [b|bl] tramp @@ -70,7 +94,7 @@ void bpf_jit_build_fentry_stubs(u32 *image, struct codegen_context *ctx) /* * Long branch stub: - * .long + * .long // 8-byte aligned * mflr r11 * bcl 20,31,$+4 * mflr r12 @@ -81,6 +105,7 @@ void bpf_jit_build_fentry_stubs(u32 *image, struct codegen_context *ctx) */ if (image) *((unsigned long *)&image[ctx->idx]) = (unsigned long)dummy_tramp; + ctx->idx += SZL / 4; long_branch_stub_idx = ctx->idx; EMIT(PPC_RAW_MFLR(_R11)); @@ -97,7 +122,8 @@ void bpf_jit_build_fentry_stubs(u32 *image, struct codegen_context *ctx) } } -int bpf_jit_emit_exit_insn(u32 *image, struct codegen_context *ctx, int tmp_reg, long exit_addr) +int bpf_jit_emit_exit_insn(u32 *image, u32 *fimage, struct codegen_context *ctx, + int tmp_reg, long exit_addr) { if (exit_addr && is_offset_in_branch_range(exit_addr - (long)(ctx->idx * 4))) { PPC_JMP(exit_addr); @@ -106,7 +132,7 @@ int bpf_jit_emit_exit_insn(u32 *image, struct codegen_context *ctx, int tmp_reg, PPC_JMP(ctx->alt_exit_addr); } else { ctx->alt_exit_addr = ctx->idx * 4; - bpf_jit_build_epilogue(image, ctx); + bpf_jit_build_epilogue(image, fimage, ctx); } return 0; @@ -286,7 +312,7 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_verifier_env *env, struct bpf_pr */ bpf_jit_build_prologue(NULL, &cgctx); addrs[fp->len] = cgctx.idx * 4; - bpf_jit_build_epilogue(NULL, &cgctx); + bpf_jit_build_epilogue(NULL, NULL, &cgctx); fixup_len = fp->aux->num_exentries * BPF_FIXUP_LEN * 4; extable_len = fp->aux->num_exentries * sizeof(struct exception_table_entry); @@ -322,7 +348,7 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_verifier_env *env, struct bpf_pr goto out_err; } addrs[fp->len] = cgctx.idx * 4; - bpf_jit_build_epilogue(code_base, &cgctx); + bpf_jit_build_epilogue(code_base, fcode_base, &cgctx); proglen = cgctx.idx * 4; diff --git a/arch/powerpc/net/bpf_jit_comp32.c b/arch/powerpc/net/bpf_jit_comp32.c index bfdc50740da8e..f5b9441cf46aa 100644 --- a/arch/powerpc/net/bpf_jit_comp32.c +++ b/arch/powerpc/net/bpf_jit_comp32.c @@ -229,7 +229,7 @@ static void bpf_jit_emit_common_epilogue(u32 *image, struct codegen_context *ctx } -void bpf_jit_build_epilogue(u32 *image, struct codegen_context *ctx) +void bpf_jit_build_epilogue(u32 *image, u32 *fimage, struct codegen_context *ctx) { EMIT(PPC_RAW_MR(_R3, bpf_to_ppc(BPF_REG_0))); @@ -237,7 +237,7 @@ void bpf_jit_build_epilogue(u32 *image, struct codegen_context *ctx) EMIT(PPC_RAW_BLR()); - bpf_jit_build_fentry_stubs(image, ctx); + bpf_jit_build_fentry_stubs(image, fimage, ctx); } /* Relative offset needs to be calculated based on final image location */ @@ -1149,7 +1149,8 @@ int bpf_jit_build_body(struct bpf_prog *fp, u32 *image, u32 *fimage, struct code * we'll just fall through to the epilogue. */ if (i != flen - 1) { - ret = bpf_jit_emit_exit_insn(image, ctx, _R0, exit_addr); + ret = bpf_jit_emit_exit_insn(image, fimage, + ctx, _R0, exit_addr); if (ret) return ret; } diff --git a/arch/powerpc/net/bpf_jit_comp64.c b/arch/powerpc/net/bpf_jit_comp64.c index fc9db691e8203..667e2d4d2c612 100644 --- a/arch/powerpc/net/bpf_jit_comp64.c +++ b/arch/powerpc/net/bpf_jit_comp64.c @@ -398,7 +398,7 @@ static void bpf_jit_emit_common_epilogue(u32 *image, struct codegen_context *ctx } } -void bpf_jit_build_epilogue(u32 *image, struct codegen_context *ctx) +void bpf_jit_build_epilogue(u32 *image, u32 *fimage, struct codegen_context *ctx) { bpf_jit_emit_common_epilogue(image, ctx); @@ -407,7 +407,7 @@ void bpf_jit_build_epilogue(u32 *image, struct codegen_context *ctx) EMIT(PPC_RAW_BLR()); - bpf_jit_build_fentry_stubs(image, ctx); + bpf_jit_build_fentry_stubs(image, fimage, ctx); } /* @@ -1737,7 +1737,8 @@ int bpf_jit_build_body(struct bpf_prog *fp, u32 *image, u32 *fimage, struct code * we'll just fall through to the epilogue. */ if (i != flen - 1) { - ret = bpf_jit_emit_exit_insn(image, ctx, tmp1_reg, exit_addr); + ret = bpf_jit_emit_exit_insn(image, fimage, ctx, + tmp1_reg, exit_addr); if (ret) return ret; } -- 2.53.0