X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?a=blobdiff_plain;f=src%2Flibsystemd%2Fsd-bus%2Fbus-message.c;h=313402933720fd81d90e3c05b57943210118ccb9;hb=ad67ef274e43ee841fb9d60e3cd2370e57418371;hp=ad417c0f100bc6d6f209d5018f109f3ec55d2df6;hpb=77adde638217112c9e080035197a76f4dc4af700;p=elogind.git diff --git a/src/libsystemd/sd-bus/bus-message.c b/src/libsystemd/sd-bus/bus-message.c index ad417c0f1..313402933 100644 --- a/src/libsystemd/sd-bus/bus-message.c +++ b/src/libsystemd/sd-bus/bus-message.c @@ -65,17 +65,19 @@ static void message_free_part(sd_bus_message *m, struct bus_body_part *part) { /* If we can reuse the memfd, try that. For that it * can't be sealed yet. */ - if (!part->sealed) + if (!part->sealed) { + assert(part->memfd_offset == 0); + assert(part->data == part->mmap_begin); bus_kernel_push_memfd(m->bus, part->memfd, part->data, part->mapped, part->allocated); - else { + } else { if (part->mapped > 0) - assert_se(munmap(part->data, part->mapped) == 0); + assert_se(munmap(part->mmap_begin, part->mapped) == 0); safe_close(part->memfd); } } else if (part->munmap_this) - munmap(part->data, part->mapped); + munmap(part->mmap_begin, part->mapped); else if (part->free_this) free(part->data); @@ -128,7 +130,7 @@ static void message_free(sd_bus_message *m) { message_reset_parts(m); if (m->release_kdbus) { - struct kdbus_cmd_free cmd_free; + struct kdbus_cmd_free cmd_free = { }; cmd_free.flags = 0; cmd_free.offset = (uint8_t *)m->kdbus - (uint8_t *)m->bus->kdbus_buffer; @@ -1103,8 +1105,10 @@ static int part_make_space( if (m->poisoned) return -ENOMEM; - if (!part->data && part->memfd < 0) + if (!part->data && part->memfd < 0) { part->memfd = bus_kernel_pop_memfd(m->bus, &part->data, &part->mapped, &part->allocated); + part->mmap_begin = part->data; + } if (part->memfd >= 0) { @@ -1126,17 +1130,18 @@ static int part_make_space( psz = PAGE_ALIGN(sz > 0 ? sz : 1); if (part->mapped <= 0) - n = mmap(NULL, psz, PROT_READ|PROT_WRITE, MAP_SHARED, part->memfd, part->memfd_offset); + n = mmap(NULL, psz, PROT_READ|PROT_WRITE, MAP_SHARED, part->memfd, 0); else - n = mremap(part->data, part->mapped, psz, MREMAP_MAYMOVE); + n = mremap(part->mmap_begin, part->mapped, psz, MREMAP_MAYMOVE); if (n == MAP_FAILED) { m->poisoned = true; return -errno; } + part->mmap_begin = part->data = n; part->mapped = psz; - part->data = n; + part->memfd_offset = 0; } part->munmap_this = true; @@ -1345,7 +1350,7 @@ int message_append_basic(sd_bus_message *m, char type, const void *p, const void } else { char *e; - /* Maybe we can append to the signature? But only if this is the top-level container*/ + /* Maybe we can append to the signature? But only if this is the top-level container */ if (c->enclosing != 0) return -ENXIO; @@ -1538,7 +1543,7 @@ _public_ int sd_bus_message_append_string_space( } else { char *e; - /* Maybe we can append to the signature? But only if this is the top-level container*/ + /* Maybe we can append to the signature? But only if this is the top-level container */ if (c->enclosing != 0) return -ENXIO; @@ -2503,10 +2508,11 @@ _public_ int sd_bus_message_append_array_space( return 0; } -_public_ int sd_bus_message_append_array(sd_bus_message *m, - char type, - const void *ptr, - size_t size) { +_public_ int sd_bus_message_append_array( + sd_bus_message *m, + char type, + const void *ptr, + size_t size) { int r; void *p; @@ -2562,26 +2568,26 @@ _public_ int sd_bus_message_append_array_iovec( return 0; } -_public_ int sd_bus_message_append_array_memfd(sd_bus_message *m, - char type, - int memfd) { +_public_ int sd_bus_message_append_array_memfd( + sd_bus_message *m, + char type, + int memfd, + uint64_t offset, + uint64_t size) { + _cleanup_close_ int copy_fd = -1; struct bus_body_part *part; ssize_t align, sz; - uint64_t size; + uint64_t real_size; void *a; int r; - if (!m) - return -EINVAL; - if (memfd < 0) - return -EINVAL; - if (m->sealed) - return -EPERM; - if (!bus_type_is_trivial(type)) - return -EINVAL; - if (m->poisoned) - return -ESTALE; + assert_return(m, -EINVAL); + assert_return(memfd >= 0, -EINVAL); + assert_return(bus_type_is_trivial(type), -EINVAL); + assert_return(size > 0, -EINVAL); + assert_return(!m->sealed, -EPERM); + assert_return(!m->poisoned, -ESTALE); r = memfd_set_sealed(memfd); if (r < 0) @@ -2591,16 +2597,24 @@ _public_ int sd_bus_message_append_array_memfd(sd_bus_message *m, if (copy_fd < 0) return copy_fd; - r = memfd_get_size(memfd, &size); + r = memfd_get_size(memfd, &real_size); if (r < 0) return r; + if (offset == 0 && size == (uint64_t) -1) + size = real_size; + else if (offset + size > real_size) + return -EMSGSIZE; + align = bus_type_get_alignment(type); sz = bus_type_get_size(type); assert_se(align > 0); assert_se(sz > 0); + if (offset % align != 0) + return -EINVAL; + if (size % sz != 0) return -EINVAL; @@ -2620,7 +2634,7 @@ _public_ int sd_bus_message_append_array_memfd(sd_bus_message *m, return -ENOMEM; part->memfd = copy_fd; - part->memfd_offset = 0; + part->memfd_offset = offset; part->sealed = true; part->size = size; copy_fd = -1; @@ -2631,16 +2645,22 @@ _public_ int sd_bus_message_append_array_memfd(sd_bus_message *m, return sd_bus_message_close_container(m); } -_public_ int sd_bus_message_append_string_memfd(sd_bus_message *m, int memfd) { +_public_ int sd_bus_message_append_string_memfd( + sd_bus_message *m, + int memfd, + uint64_t offset, + uint64_t size) { + _cleanup_close_ int copy_fd = -1; struct bus_body_part *part; struct bus_container *c; - uint64_t size; + uint64_t real_size; void *a; int r; assert_return(m, -EINVAL); assert_return(memfd >= 0, -EINVAL); + assert_return(size > 0, -EINVAL); assert_return(!m->sealed, -EPERM); assert_return(!m->poisoned, -ESTALE); @@ -2652,10 +2672,15 @@ _public_ int sd_bus_message_append_string_memfd(sd_bus_message *m, int memfd) { if (copy_fd < 0) return copy_fd; - r = memfd_get_size(memfd, &size); + r = memfd_get_size(memfd, &real_size); if (r < 0) return r; + if (offset == 0 && size == (uint64_t) -1) + size = real_size; + else if (offset + size > real_size) + return -EMSGSIZE; + /* We require this to be NUL terminated */ if (size == 0) return -EINVAL; @@ -2672,7 +2697,7 @@ _public_ int sd_bus_message_append_string_memfd(sd_bus_message *m, int memfd) { } else { char *e; - /* Maybe we can append to the signature? But only if this is the top-level container*/ + /* Maybe we can append to the signature? But only if this is the top-level container */ if (c->enclosing != 0) return -ENXIO; @@ -2696,7 +2721,7 @@ _public_ int sd_bus_message_append_string_memfd(sd_bus_message *m, int memfd) { return -ENOMEM; part->memfd = copy_fd; - part->memfd_offset = 0; + part->memfd_offset = offset; part->sealed = true; part->size = size; copy_fd = -1; @@ -2860,7 +2885,7 @@ int bus_message_seal(sd_bus_message *m, uint64_t cookie, usec_t timeout) { int bus_body_part_map(struct bus_body_part *part) { void *p; - size_t psz; + size_t psz, shift; assert_se(part); @@ -2877,10 +2902,11 @@ int bus_body_part_map(struct bus_body_part *part) { return 0; } - psz = PAGE_ALIGN(part->size); + shift = part->memfd_offset - ((part->memfd_offset / page_size()) * page_size()); + psz = PAGE_ALIGN(part->size + shift); if (part->memfd >= 0) - p = mmap(NULL, psz, PROT_READ, MAP_PRIVATE, part->memfd, part->memfd_offset); + p = mmap(NULL, psz, PROT_READ, MAP_PRIVATE, part->memfd, part->memfd_offset - shift); else if (part->is_zero) p = mmap(NULL, psz, PROT_READ, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0); else @@ -2890,7 +2916,8 @@ int bus_body_part_map(struct bus_body_part *part) { return -errno; part->mapped = psz; - part->data = p; + part->mmap_begin = p; + part->data = (uint8_t*) p + shift; part->munmap_this = true; return 0; @@ -2903,14 +2930,15 @@ void bus_body_part_unmap(struct bus_body_part *part) { if (part->memfd < 0) return; - if (!part->data) + if (!part->mmap_begin) return; if (!part->munmap_this) return; - assert_se(munmap(part->data, part->mapped) == 0); + assert_se(munmap(part->mmap_begin, part->mapped) == 0); + part->mmap_begin = NULL; part->data = NULL; part->mapped = 0; part->munmap_this = false;