From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dave Jones Subject: Re: [PATCH v2] Fix build on older kernels without BPF. Date: Thu, 4 Aug 2016 16:36:06 -0400 Message-ID: <20160804203606.gpulsvdyjr5mvzq3@codemonkey.org.uk> References: <20160712190217.GA5525@codemonkey.org.uk> <1468359236-6940-1-git-send-email-vlee@freedesktop.org> <20160721201048.GA9384@codemonkey.org.uk> <20160726005929.GA17542@codemonkey.org.uk> Mime-Version: 1.0 Return-path: Content-Disposition: inline In-Reply-To: <20160726005929.GA17542@codemonkey.org.uk> Sender: trinity-owner@vger.kernel.org List-ID: Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Vinson Lee Cc: trinity@vger.kernel.org On Mon, Jul 25, 2016 at 08:59:29PM -0400, Dave Jones wrote: > > tables.c > > 470 static struct syscalltable * copy_syscall_table(struct > > syscalltable *from, unsigned int nr) > > 471 { > > 472 unsigned int n; > > 473 struct syscallentry *copy; > > 474 > > 475 copy = alloc_shared(nr * sizeof(struct syscallentry)); > > 476 if (copy == NULL) > > 477 exit(EXIT_FAILURE); > > 478 > > 479 for (n = 0; n < nr; n++) { > > 480 memcpy(copy + n , from[n].entry, sizeof(struct > > syscallentry)); > > 481 copy[n].number = n; > > 482 copy[n].active_number = 0; > > 483 from[n].entry = ©[n]; > > 484 } > > 485 return from; > > 486 } > > > stick a > if (from[n] == NULL) > continue > > before the memcpy. Does that dtrt ? > > We might segv somewhere else after patching this up. It's been so long since > I touched this stuff I don't fully recall how it works. I'll poke at it > some tomorrow. Just getting around to this. It's a bit more involved than I hoped. Spraying a bunch of null checks around like this seems to be the thing to do.. Let me know how this works out for you. Dave diff --git a/configure b/configure index 8d959298f129..93cf19c5861c 100755 --- a/configure +++ b/configure @@ -239,6 +239,7 @@ check_header execinfo.h USE_BACKTRACE check_header netatalk/at.h USE_APPLETALK check_header netrom/netrom.h USE_NETROM check_header netrose/rose.h USE_ROSE +check_header linux/bfp.h USE_BPFF rm -f "$TMP" "$TMP.log" "$TMP.c" diff --git a/include/syscalls-aarch64.h b/include/syscalls-aarch64.h index 09acf418a12e..fda0814128bc 100644 --- a/include/syscalls-aarch64.h +++ b/include/syscalls-aarch64.h @@ -290,6 +290,10 @@ struct syscalltable syscalls_aarch64[] = { /* 277 */ { .entry = &syscall_seccomp }, /* 278 */ { .entry = &syscall_getrandom }, /* 279 */ { .entry = &syscall_memfd_create }, +#ifdef USE_BPF /* 280 */ { .entry = &syscall_bpf }, +#else + { .entry = NULL }, +#endif /* 281 */ { .entry = &syscall_execveat }, }; diff --git a/include/syscalls-arm.h b/include/syscalls-arm.h index 7ecc4353a835..0f40e57e5501 100644 --- a/include/syscalls-arm.h +++ b/include/syscalls-arm.h @@ -396,7 +396,11 @@ struct syscalltable syscalls_arm[] = { { .entry = &syscall_seccomp }, { .entry = &syscall_getrandom }, /* 385 */ { .entry = &syscall_memfd_create }, +#ifdef USE_BPF { .entry = &syscall_bpf }, +#else + { .entry = NULL }, +#endif { .entry = &syscall_execveat }, { .entry = &syscall_userfaultfd }, { .entry = &syscall_membarrier }, diff --git a/include/syscalls-i386.h b/include/syscalls-i386.h index 147b1eb12607..316836406674 100644 --- a/include/syscalls-i386.h +++ b/include/syscalls-i386.h @@ -364,7 +364,11 @@ struct syscalltable syscalls_i386[] = { { .entry = &syscall_seccomp }, { .entry = &syscall_getrandom }, { .entry = &syscall_memfd_create }, +#ifdef USE_BPF { .entry = &syscall_bpf }, +#else + { .entry = NULL }, +#endif { .entry = &syscall_execveat }, { .entry = &syscall_socket }, { .entry = &syscall_socketpair }, diff --git a/include/syscalls-ia64.h b/include/syscalls-ia64.h index 28eacce0ac3d..5efcb7d42f88 100644 --- a/include/syscalls-ia64.h +++ b/include/syscalls-ia64.h @@ -324,7 +324,11 @@ struct syscalltable syscalls_ia64[] = { { .entry = &syscall_renameat2 }, { .entry = &syscall_getrandom }, { .entry = &syscall_memfd_create }, +#ifdef USE_BPF { .entry = &syscall_bpf }, +#else + { .entry = NULL }, +#endif { .entry = &syscall_userfaultfd }, { .entry = &syscall_membarrier }, { .entry = &syscall_kcmp }, diff --git a/include/syscalls-mips.h b/include/syscalls-mips.h index 273ba257db1c..26130f323f4a 100644 --- a/include/syscalls-mips.h +++ b/include/syscalls-mips.h @@ -371,5 +371,9 @@ struct syscalltable syscalls_mips[] = { { .entry = &syscall_seccomp }, { .entry = &syscall_getrandom }, { .entry = &syscall_memfd_create }, +#ifdef USE_BPF { .entry = &syscall_bpf }, /* 4355 */ +#else + { .entry = NULL }, +#endif }; diff --git a/include/syscalls-parisc.h b/include/syscalls-parisc.h index 8d164e501b12..2ac2d5f9513e 100644 --- a/include/syscalls-parisc.h +++ b/include/syscalls-parisc.h @@ -348,6 +348,10 @@ struct syscalltable syscalls_parisc[] = { { .entry = &syscall_seccomp }, { .entry = &syscall_getrandom }, { .entry = &syscall_memfd_create }, +#ifdef USE_BPF { .entry = &syscall_bpf }, +#else + { .entry = NULL }, +#endif { .entry = &syscall_execveat }, }; diff --git a/include/syscalls-s390.h b/include/syscalls-s390.h index dd9c93aeae04..9916e6c6e772 100644 --- a/include/syscalls-s390.h +++ b/include/syscalls-s390.h @@ -358,7 +358,11 @@ struct syscalltable syscalls_s390[] = { { .entry = &syscall_seccomp }, { .entry = &syscall_getrandom }, { .entry = &syscall_memfd_create }, +#ifdef USE_BPF { .entry = &syscall_bpf }, +#else + { .entry = NULL }, +#endif { .entry = &syscall_ni_syscall }, // TODO: syscall_s390_pci_mmio_write { .entry = &syscall_ni_syscall }, // TODO: syscall_s390_pci_mmio_read { .entry = &syscall_execveat }, diff --git a/include/syscalls-s390x.h b/include/syscalls-s390x.h index 6ddeb85ea39d..6dbaffb37397 100644 --- a/include/syscalls-s390x.h +++ b/include/syscalls-s390x.h @@ -358,7 +358,11 @@ struct syscalltable syscalls_s390x[] = { { .entry = &syscall_seccomp }, { .entry = &syscall_getrandom }, { .entry = &syscall_memfd_create }, +#ifdef USE_BPF { .entry = &syscall_bpf }, +#else + { .entry = NULL }, +#endif { .entry = &syscall_ni_syscall }, // TODO: syscall_s390_pci_mmio_write { .entry = &syscall_ni_syscall }, // TODO: syscall_s390_pci_mmio_read { .entry = &syscall_execveat }, diff --git a/include/syscalls-sparc.h b/include/syscalls-sparc.h index 5cedd89b4fee..dbdd4e8d4620 100644 --- a/include/syscalls-sparc.h +++ b/include/syscalls-sparc.h @@ -356,6 +356,10 @@ struct syscalltable syscalls_sparc[] = { { .entry = &syscall_seccomp }, { .entry = &syscall_getrandom }, { .entry = &syscall_memfd_create }, +#ifdef USE_BPF { .entry = &syscall_bpf }, +#else + { .entry = NULL }, +#endif { .entry = &syscall_execveat }, }; diff --git a/include/syscalls-x86_64.h b/include/syscalls-x86_64.h index c75f4dee142f..cc67889e7e23 100644 --- a/include/syscalls-x86_64.h +++ b/include/syscalls-x86_64.h @@ -328,7 +328,11 @@ struct syscalltable syscalls_x86_64[] = { { .entry = &syscall_seccomp }, { .entry = &syscall_memfd_create }, { .entry = &syscall_kexec_file_load }, +#ifdef USE_BPF { .entry = &syscall_bpf }, +#else + { .entry = NULL }, +#endif { .entry = &syscall_execveat }, { .entry = &syscall_userfaultfd }, { .entry = &syscall_membarrier }, diff --git a/syscalls/bpf.c b/syscalls/bpf.c index b2f57d36feff..476a2778d8a0 100644 --- a/syscalls/bpf.c +++ b/syscalls/bpf.c @@ -1,6 +1,7 @@ /* * SYSCALL_DEFINE3(bpf, int, cmd, union bpf_attr __user *, uattr, unsigned int, size) */ +#ifdef USE_BPF #include #include #include "arch.h" @@ -102,3 +103,4 @@ struct syscallentry syscall_bpf = { .sanitise = sanitise_bpf, .post = post_bpf, }; +#endif diff --git a/tables-biarch.c b/tables-biarch.c index 635aac966880..53e9b8330615 100644 --- a/tables-biarch.c +++ b/tables-biarch.c @@ -216,8 +216,12 @@ int setup_syscall_group_biarch(unsigned int group) unsigned int i; for_each_32bit_syscall(i) { - if (syscalls_32bit[i].entry->group == group) - toggle_syscall(syscalls_32bit[i].entry->name, TRUE); + struct syscallentry *entry = syscalls_32bit[i].entry; + if (entry == NULL) + continue; + + if (entry->group == group) + toggle_syscall(entry->name, TRUE); } if (shm->nr_active_32bit_syscalls == 0) @@ -227,8 +231,12 @@ int setup_syscall_group_biarch(unsigned int group) /* now the 64 bit table*/ for_each_64bit_syscall(i) { - if (syscalls_64bit[i].entry->group == group) - toggle_syscall(syscalls_64bit[i].entry->name, TRUE); + struct syscallentry *entry = syscalls_64bit[i].entry; + if (entry == NULL) + continue; + + if (entry->group == group) + toggle_syscall(entry->name, TRUE); } if (shm->nr_active_64bit_syscalls == 0) { @@ -247,14 +255,20 @@ void mark_all_syscalls_active_biarch(void) if (do_32_arch) { for_each_32bit_syscall(i) { - syscalls_32bit[i].entry->flags |= ACTIVE; + struct syscallentry *entry = syscalls_32bit[i].entry; + if (entry == NULL) + continue; + entry->flags |= ACTIVE; activate_syscall32(i); } } if (do_64_arch) { for_each_64bit_syscall(i) { - syscalls_64bit[i].entry->flags |= ACTIVE; + struct syscallentry *entry = syscalls_64bit[i].entry; + if (entry == NULL) + continue; + entry->flags |= ACTIVE; activate_syscall64(i); } } @@ -267,6 +281,9 @@ void init_syscalls_biarch(void) for_each_64bit_syscall(i) { entry = syscalls_64bit[i].entry; + if (entry == NULL) + continue; + if (entry->flags & ACTIVE) if (entry->init) entry->init(); @@ -274,6 +291,9 @@ void init_syscalls_biarch(void) for_each_32bit_syscall(i) { entry = syscalls_32bit[i].entry; + if (entry == NULL) + continue; + if (entry->flags & ACTIVE) if (entry->init) entry->init(); @@ -287,6 +307,9 @@ void deactivate_disabled_syscalls_biarch(void) for_each_64bit_syscall(i) { entry = syscalls_64bit[i].entry; + if (entry == NULL) + continue; + if (entry->flags & TO_BE_DEACTIVATED) { entry->flags &= ~(ACTIVE|TO_BE_DEACTIVATED); deactivate_syscall64(i); @@ -297,6 +320,9 @@ void deactivate_disabled_syscalls_biarch(void) for_each_32bit_syscall(i) { entry = syscalls_32bit[i].entry; + if (entry == NULL) + continue; + if (entry->flags & TO_BE_DEACTIVATED) { entry->flags &= ~(ACTIVE|TO_BE_DEACTIVATED); deactivate_syscall32(i); @@ -316,6 +342,9 @@ void dump_syscall_tables_biarch(void) for_each_32bit_syscall(i) { entry = syscalls_32bit[i].entry; + if (entry == NULL) + continue; + outputstd("entrypoint %d %s : [32-bit] ", entry->number, entry->name); show_state(entry->flags & ACTIVE); @@ -328,6 +357,8 @@ void dump_syscall_tables_biarch(void) for_each_64bit_syscall(i) { entry = syscalls_64bit[i].entry; + if (entry == NULL) + continue; outputstd("entrypoint %d %s : [64-bit] ", entry->number, entry->name); @@ -347,12 +378,18 @@ void display_enabled_syscalls_biarch(void) for_each_64bit_syscall(i) { entry = syscalls_64bit[i].entry; + if (entry == NULL) + continue; + if (entry->flags & ACTIVE) output(0, "64-bit syscall %d:%s enabled.\n", i, entry->name); } for_each_32bit_syscall(i) { entry = syscalls_32bit[i].entry; + if (entry == NULL) + continue; + if (entry->flags & ACTIVE) output(0, "32-bit syscall %d:%s enabled.\n", i, entry->name); } diff --git a/tables-uniarch.c b/tables-uniarch.c index 8f6bcd6553e1..5ba385e6fb74 100644 --- a/tables-uniarch.c +++ b/tables-uniarch.c @@ -100,7 +100,11 @@ void mark_all_syscalls_active_uniarch(void) unsigned int i; for_each_syscall(i) { - syscalls[i].entry->flags |= ACTIVE; + struct syscallentry *entry = syscalls[i].entry; + if (entry == NULL) + continue; + + entry->flags |= ACTIVE; activate_syscall(i); } } @@ -110,9 +114,10 @@ void init_syscalls_uniarch(void) unsigned int i; for_each_syscall(i) { - struct syscallentry *entry; + struct syscallentry *entry = syscalls[i].entry; + if (entry == NULL) + continue; - entry = syscalls[i].entry; if (entry->flags & ACTIVE) if (entry->init) entry->init(); @@ -124,9 +129,11 @@ void deactivate_disabled_syscalls_uniarch(void) unsigned int i; for_each_syscall(i) { - struct syscallentry *entry; + struct syscallentry *entry = syscalls[i].entry; + + if (entry == NULL) + continue; - entry = syscalls[i].entry; if (entry->flags & TO_BE_DEACTIVATED) { entry->flags &= ~(ACTIVE|TO_BE_DEACTIVATED); deactivate_syscall_uniarch(i); @@ -143,9 +150,11 @@ void dump_syscall_tables_uniarch(void) outputstd("syscalls: %d\n", max_nr_syscalls); for_each_syscall(i) { - struct syscallentry *entry; + struct syscallentry *entry = syscalls[i].entry; + + if (entry == NULL) + continue; - entry = syscalls[i].entry; outputstd("entrypoint %d %s : ", entry->number, entry->name); show_state(entry->flags & ACTIVE); if (entry->flags & AVOID_SYSCALL) @@ -159,9 +168,10 @@ void display_enabled_syscalls_uniarch(void) unsigned int i; for_each_syscall(i) { - struct syscallentry *entry; + struct syscallentry *entry = syscalls[i].entry; - entry = syscalls[i].entry; + if (entry == NULL) + continue; if (entry->flags & ACTIVE) output(0, "syscall %d:%s enabled.\n", i, entry->name); diff --git a/tables.c b/tables.c index 7d5d35b7d2fa..8d3f4d7d8a6e 100644 --- a/tables.c +++ b/tables.c @@ -211,6 +211,8 @@ static void check_syscall(struct syscallentry *entry) { /* check that we have a name set. */ #define CHECK(NUMARGS, ARGNUM, ARGTYPE, ARGNAME) \ + if (entry == NULL) \ + return; \ if (entry->num_args > 0) { \ if (entry->num_args > NUMARGS) { \ if (entry->ARGNAME == NULL) { \ @@ -231,6 +233,8 @@ static void check_syscall(struct syscallentry *entry) /* note: not enabled by default, because we haven't annotated everything yet. */ #undef CHECK #define CHECK(NUMARGS, ARGNUM, ARGTYPE, ARGNAME) \ + if (entry == NULL) \ + return; \ if (entry->num_args > 0) { \ if (entry->num_args > NUMARGS) { \ if (entry->ARGTYPE == ARG_UNDEFINED) { \ @@ -379,6 +383,9 @@ static void show_unannotated_biarch(void) for_each_32bit_syscall(i) { entry = syscalls_32bit[i].entry; + if (entry == NULL) + continue; + count = 0; for (j = 1; j <= entry->num_args; j++) { @@ -415,6 +422,9 @@ static void show_unannotated_biarch(void) for_each_64bit_syscall(i) { entry = syscalls_64bit[i].entry; + if (entry == NULL) + continue; + count = 0; for (j = 1; j <= entry->num_args; j++) { @@ -469,18 +479,24 @@ void show_unannotated_args(void) */ static struct syscalltable * copy_syscall_table(struct syscalltable *from, unsigned int nr) { - unsigned int n; + unsigned int n, m; struct syscallentry *copy; copy = alloc_shared(nr * sizeof(struct syscallentry)); if (copy == NULL) exit(EXIT_FAILURE); - for (n = 0; n < nr; n++) { - memcpy(copy + n , from[n].entry, sizeof(struct syscallentry)); - copy[n].number = n; - copy[n].active_number = 0; - from[n].entry = ©[n]; + for (n = 0, m = 0; n < nr; n++) { + struct syscallentry *entry = from[n].entry; + + if (entry == NULL) + continue; + + memcpy(copy + m , from[n].entry, sizeof(struct syscallentry)); + copy[m].number = n; + copy[m].active_number = 0; + from[n].entry = ©[m]; + m++; } return from; }