From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from ozlabs.org (ozlabs.org [103.22.144.67]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 3rZCXz0p6NzDqFM for ; Wed, 22 Jun 2016 15:18:11 +1000 (AEST) Message-ID: <1466572690.19785.4.camel@ellerman.id.au> Subject: Re: [PATCH] ppc: Fix BPF JIT for ABIv2 From: Michael Ellerman To: Thadeu Lima de Souza Cascardo Cc: "Naveen N. Rao" , linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, netdev@vger.kernel.org, Matt Evans , Daniel Borkmann , Alexei Starovoitov , Denis Kirjanov , Paul Mackerras , "David S. Miller" , Ananth N Mavinakayanahalli Date: Wed, 22 Jun 2016 15:18:10 +1000 In-Reply-To: <20160617130042.GO3516@indiana.gru.redhat.com> References: <908d3552b5eb240b28f70aee7c4c86e2b600aa02.1465304785.git.naveen.n.rao@linux.vnet.ibm.com> <3rWKtT2tSrz9t2G@ozlabs.org> <20160617130042.GO3516@indiana.gru.redhat.com> Content-Type: text/plain; charset="UTF-8" Mime-Version: 1.0 List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Fri, 2016-06-17 at 10:00 -0300, Thadeu Lima de Souza Cascardo wrote: > From a984dc02b6317a1d3a3c2302385adba5227be5bd Mon Sep 17 00:00:00 2001 > From: Thadeu Lima de Souza Cascardo > Date: Wed, 15 Jun 2016 13:22:12 -0300 > Subject: [PATCH] ppc: Fix BPF JIT for ABIv2 > > ABIv2 used for ppc64le does not use function descriptors. Without this patch, > whenever BPF JIT is enabled, we get a crash as below. > ... > diff --git a/arch/powerpc/net/bpf_jit.h b/arch/powerpc/net/bpf_jit.h > index 889fd19..28b89ed 100644 > --- a/arch/powerpc/net/bpf_jit.h > +++ b/arch/powerpc/net/bpf_jit.h > @@ -70,7 +70,7 @@ DECLARE_LOAD_FUNC(sk_load_half); > DECLARE_LOAD_FUNC(sk_load_byte); > DECLARE_LOAD_FUNC(sk_load_byte_msh); > > -#ifdef CONFIG_PPC64 > +#if defined(CONFIG_PPC64) && (!defined(_CALL_ELF) || _CALL_ELF != 2) > #define FUNCTION_DESCR_SIZE 24 > #else > #define FUNCTION_DESCR_SIZE 0 > diff --git a/arch/powerpc/net/bpf_jit_comp.c b/arch/powerpc/net/bpf_jit_comp.c > index 2d66a84..035b887 100644 > --- a/arch/powerpc/net/bpf_jit_comp.c > +++ b/arch/powerpc/net/bpf_jit_comp.c > @@ -664,7 +664,7 @@ void bpf_jit_compile(struct bpf_prog *fp) > > if (image) { > bpf_flush_icache(code_base, code_base + (proglen/4)); > -#ifdef CONFIG_PPC64 > +#if defined(CONFIG_PPC64) && (!defined(_CALL_ELF) || _CALL_ELF != 2) > /* Function descriptor nastiness: Address + TOC */ > ((u64 *)image)[0] = (u64)code_base; > ((u64 *)image)[1] = local_paca->kernel_toc; Confirmed that even with this patch we still crash: # echo 1 > /proc/sys/net/core/bpf_jit_enable # modprobe test_bpf BPF filter opcode 0020 (@3) unsupported BPF filter opcode 0020 (@2) unsupported BPF filter opcode 0020 (@0) unsupported Unable to handle kernel paging request for data at address 0xd0000000054f65e8 Faulting instruction address: 0xc0000000008765f8 cpu 0x0: Vector: 300 (Data Access) at [c0000000034f3480] pc: c0000000008765f8: skb_copy_bits+0x158/0x330 lr: c00000000008fb7c: bpf_slow_path_byte+0x28/0x54 sp: c0000000034f3700 msr: 800000010280b033 dar: d0000000054f65e8 dsisr: 40000000 current = 0xc0000001f857d8d0 paca = 0xc000000007b80000 softe: 0 irq_happened: 0x01 pid = 2993, comm = modprobe Linux version 4.7.0-rc3-00055-g9497a1c1c5b4-dirty (michael@ka3.ozlabs.ibm.com) () #30 SMP Wed Jun 22 15:06:58 AEST 2016 enter ? for help [c0000000034f3770] c00000000008fb7c bpf_slow_path_byte+0x28/0x54 [c0000000034f37e0] d000000007bb004c [c0000000034f3900] d000000005331668 test_bpf_init+0x5fc/0x7f8 [test_bpf] [c0000000034f3a30] c00000000000b628 do_one_initcall+0x68/0x1d0 [c0000000034f3af0] c0000000009beb24 do_init_module+0x90/0x240 [c0000000034f3b80] c0000000001642bc load_module+0x206c/0x22f0 [c0000000034f3d30] c0000000001648b0 SyS_finit_module+0x120/0x180 [c0000000034f3e30] c000000000009260 system_call+0x38/0x108 --- Exception: c01 (System Call) at 00003fff7ffa2db4 cheers From mboxrd@z Thu Jan 1 00:00:00 1970 From: Michael Ellerman Subject: Re: [PATCH] ppc: Fix BPF JIT for ABIv2 Date: Wed, 22 Jun 2016 15:18:10 +1000 Message-ID: <1466572690.19785.4.camel@ellerman.id.au> References: <908d3552b5eb240b28f70aee7c4c86e2b600aa02.1465304785.git.naveen.n.rao@linux.vnet.ibm.com> <3rWKtT2tSrz9t2G@ozlabs.org> <20160617130042.GO3516@indiana.gru.redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Cc: Matt Evans , Daniel Borkmann , Alexei Starovoitov , netdev@vger.kernel.org, Denis Kirjanov , linux-kernel@vger.kernel.org, Paul Mackerras , "Naveen N. Rao" , linuxppc-dev@lists.ozlabs.org, "David S. Miller" , Ananth N Mavinakayanahalli To: Thadeu Lima de Souza Cascardo Return-path: In-Reply-To: <20160617130042.GO3516@indiana.gru.redhat.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: linuxppc-dev-bounces+glppe-linuxppc-embedded-2=m.gmane.org@lists.ozlabs.org Sender: "Linuxppc-dev" List-Id: netdev.vger.kernel.org T24gRnJpLCAyMDE2LTA2LTE3IGF0IDEwOjAwIC0wMzAwLCBUaGFkZXUgTGltYSBkZSBTb3V6YSBD YXNjYXJkbyB3cm90ZToKPiBGcm9tIGE5ODRkYzAyYjYzMTdhMWQzYTNjMjMwMjM4NWFkYmE1MjI3 YmU1YmQgTW9uIFNlcCAxNyAwMDowMDowMCAyMDAxCj4gRnJvbTogVGhhZGV1IExpbWEgZGUgU291 emEgQ2FzY2FyZG8gPGNhc2NhcmRvQHJlZGhhdC5jb20+Cj4gRGF0ZTogV2VkLCAxNSBKdW4gMjAx NiAxMzoyMjoxMiAtMDMwMAo+IFN1YmplY3Q6IFtQQVRDSF0gcHBjOiBGaXggQlBGIEpJVCBmb3Ig QUJJdjIKPiAKPiBBQkl2MiB1c2VkIGZvciBwcGM2NGxlIGRvZXMgbm90IHVzZSBmdW5jdGlvbiBk ZXNjcmlwdG9ycy4gV2l0aG91dCB0aGlzIHBhdGNoLAo+IHdoZW5ldmVyIEJQRiBKSVQgaXMgZW5h YmxlZCwgd2UgZ2V0IGEgY3Jhc2ggYXMgYmVsb3cuCj4gCi4uLgoKPiBkaWZmIC0tZ2l0IGEvYXJj aC9wb3dlcnBjL25ldC9icGZfaml0LmggYi9hcmNoL3Bvd2VycGMvbmV0L2JwZl9qaXQuaAo+IGlu ZGV4IDg4OWZkMTkuLjI4Yjg5ZWQgMTAwNjQ0Cj4gLS0tIGEvYXJjaC9wb3dlcnBjL25ldC9icGZf aml0LmgKPiArKysgYi9hcmNoL3Bvd2VycGMvbmV0L2JwZl9qaXQuaAo+IEBAIC03MCw3ICs3MCw3 IEBAIERFQ0xBUkVfTE9BRF9GVU5DKHNrX2xvYWRfaGFsZik7Cj4gIERFQ0xBUkVfTE9BRF9GVU5D KHNrX2xvYWRfYnl0ZSk7Cj4gIERFQ0xBUkVfTE9BRF9GVU5DKHNrX2xvYWRfYnl0ZV9tc2gpOwo+ ICAKPiAtI2lmZGVmIENPTkZJR19QUEM2NAo+ICsjaWYgZGVmaW5lZChDT05GSUdfUFBDNjQpICYm ICghZGVmaW5lZChfQ0FMTF9FTEYpIHx8IF9DQUxMX0VMRiAhPSAyKQo+ICAjZGVmaW5lIEZVTkNU SU9OX0RFU0NSX1NJWkUJMjQKPiAgI2Vsc2UKPiAgI2RlZmluZSBGVU5DVElPTl9ERVNDUl9TSVpF CTAKPiBkaWZmIC0tZ2l0IGEvYXJjaC9wb3dlcnBjL25ldC9icGZfaml0X2NvbXAuYyBiL2FyY2gv cG93ZXJwYy9uZXQvYnBmX2ppdF9jb21wLmMKPiBpbmRleCAyZDY2YTg0Li4wMzViODg3IDEwMDY0 NAo+IC0tLSBhL2FyY2gvcG93ZXJwYy9uZXQvYnBmX2ppdF9jb21wLmMKPiArKysgYi9hcmNoL3Bv d2VycGMvbmV0L2JwZl9qaXRfY29tcC5jCj4gQEAgLTY2NCw3ICs2NjQsNyBAQCB2b2lkIGJwZl9q aXRfY29tcGlsZShzdHJ1Y3QgYnBmX3Byb2cgKmZwKQo+ICAKPiAgCWlmIChpbWFnZSkgewo+ICAJ CWJwZl9mbHVzaF9pY2FjaGUoY29kZV9iYXNlLCBjb2RlX2Jhc2UgKyAocHJvZ2xlbi80KSk7Cj4g LSNpZmRlZiBDT05GSUdfUFBDNjQKPiArI2lmIGRlZmluZWQoQ09ORklHX1BQQzY0KSAmJiAoIWRl ZmluZWQoX0NBTExfRUxGKSB8fCBfQ0FMTF9FTEYgIT0gMikKPiAgCQkvKiBGdW5jdGlvbiBkZXNj cmlwdG9yIG5hc3RpbmVzczogQWRkcmVzcyArIFRPQyAqLwo+ICAJCSgodTY0ICopaW1hZ2UpWzBd ID0gKHU2NCljb2RlX2Jhc2U7Cj4gIAkJKCh1NjQgKilpbWFnZSlbMV0gPSBsb2NhbF9wYWNhLT5r ZXJuZWxfdG9jOwoKCkNvbmZpcm1lZCB0aGF0IGV2ZW4gd2l0aCB0aGlzIHBhdGNoIHdlIHN0aWxs IGNyYXNoOgoKICAjIGVjaG8gMSA+IC9wcm9jL3N5cy9uZXQvY29yZS9icGZfaml0X2VuYWJsZQog ICMgbW9kcHJvYmUgdGVzdF9icGYKICBCUEYgZmlsdGVyIG9wY29kZSAwMDIwIChAMykgdW5zdXBw b3J0ZWQKICBCUEYgZmlsdGVyIG9wY29kZSAwMDIwIChAMikgdW5zdXBwb3J0ZWQKICBCUEYgZmls dGVyIG9wY29kZSAwMDIwIChAMCkgdW5zdXBwb3J0ZWQKICBVbmFibGUgdG8gaGFuZGxlIGtlcm5l bCBwYWdpbmcgcmVxdWVzdCBmb3IgZGF0YSBhdCBhZGRyZXNzIDB4ZDAwMDAwMDAwNTRmNjVlOAog IEZhdWx0aW5nIGluc3RydWN0aW9uIGFkZHJlc3M6IDB4YzAwMDAwMDAwMDg3NjVmOAogIGNwdSAw eDA6IFZlY3RvcjogMzAwIChEYXRhIEFjY2VzcykgYXQgW2MwMDAwMDAwMDM0ZjM0ODBdCiAgICAg IHBjOiBjMDAwMDAwMDAwODc2NWY4OiBza2JfY29weV9iaXRzKzB4MTU4LzB4MzMwCiAgICAgIGxy OiBjMDAwMDAwMDAwMDhmYjdjOiBicGZfc2xvd19wYXRoX2J5dGUrMHgyOC8weDU0CiAgICAgIHNw OiBjMDAwMDAwMDAzNGYzNzAwCiAgICAgbXNyOiA4MDAwMDAwMTAyODBiMDMzCiAgICAgZGFyOiBk MDAwMDAwMDA1NGY2NWU4CiAgIGRzaXNyOiA0MDAwMDAwMAogICAgY3VycmVudCA9IDB4YzAwMDAw MDFmODU3ZDhkMAogICAgcGFjYSAgICA9IDB4YzAwMDAwMDAwN2I4MDAwMAkgc29mdGU6IDAJIGly cV9oYXBwZW5lZDogMHgwMQogICAgICBwaWQgICA9IDI5OTMsIGNvbW0gPSBtb2Rwcm9iZQogIExp bnV4IHZlcnNpb24gNC43LjAtcmMzLTAwMDU1LWc5NDk3YTFjMWM1YjQtZGlydHkgKG1pY2hhZWxA a2EzLm96bGFicy5pYm0uY29tKSAoKSAjMzAgU01QIFdlZCBKdW4gMjIgMTU6MDY6NTggQUVTVCAy MDE2CiAgZW50ZXIgPyBmb3IgaGVscAogIFtjMDAwMDAwMDAzNGYzNzcwXSBjMDAwMDAwMDAwMDhm YjdjIGJwZl9zbG93X3BhdGhfYnl0ZSsweDI4LzB4NTQKICBbYzAwMDAwMDAwMzRmMzdlMF0gZDAw MDAwMDAwN2JiMDA0YwogIFtjMDAwMDAwMDAzNGYzOTAwXSBkMDAwMDAwMDA1MzMxNjY4IHRlc3Rf YnBmX2luaXQrMHg1ZmMvMHg3ZjggW3Rlc3RfYnBmXQogIFtjMDAwMDAwMDAzNGYzYTMwXSBjMDAw MDAwMDAwMDBiNjI4IGRvX29uZV9pbml0Y2FsbCsweDY4LzB4MWQwCiAgW2MwMDAwMDAwMDM0ZjNh ZjBdIGMwMDAwMDAwMDA5YmViMjQgZG9faW5pdF9tb2R1bGUrMHg5MC8weDI0MAogIFtjMDAwMDAw MDAzNGYzYjgwXSBjMDAwMDAwMDAwMTY0MmJjIGxvYWRfbW9kdWxlKzB4MjA2Yy8weDIyZjAKICBb YzAwMDAwMDAwMzRmM2QzMF0gYzAwMDAwMDAwMDE2NDhiMCBTeVNfZmluaXRfbW9kdWxlKzB4MTIw LzB4MTgwCiAgW2MwMDAwMDAwMDM0ZjNlMzBdIGMwMDAwMDAwMDAwMDkyNjAgc3lzdGVtX2NhbGwr MHgzOC8weDEwOAogIC0tLSBFeGNlcHRpb246IGMwMSAoU3lzdGVtIENhbGwpIGF0IDAwMDAzZmZm N2ZmYTJkYjQKCgpjaGVlcnMKCl9fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19f X19fX19fX19fCkxpbnV4cHBjLWRldiBtYWlsaW5nIGxpc3QKTGludXhwcGMtZGV2QGxpc3RzLm96 bGFicy5vcmcKaHR0cHM6Ly9saXN0cy5vemxhYnMub3JnL2xpc3RpbmZvL2xpbnV4cHBjLWRldg==