[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [PATCH v2 3/6] xen/livepatch: simplify and unify logic in prepare_payload()
The following sections: .note.gnu.build-id, .livepatch.xen_depends and .livepatch.depends are mandatory and ensured to be present by check_special_sections() before prepare_payload() is called. Simplify the logic in prepare_payload() by introducing a generic function to parse the sections that contain a buildid. Note the function assumes the buildid related section to always be present. No functional change intended. Signed-off-by: Roger Pau Monné <roger.pau@xxxxxxxxxx> --- Changes since v1: - Rename. - Change order of assert. --- xen/common/livepatch.c | 110 +++++++++++++++++++---------------------- 1 file changed, 50 insertions(+), 60 deletions(-) diff --git a/xen/common/livepatch.c b/xen/common/livepatch.c index 87b3db03e26d..8e61083f23a7 100644 --- a/xen/common/livepatch.c +++ b/xen/common/livepatch.c @@ -470,6 +470,31 @@ static int xen_build_id_dep(const struct payload *payload) return 0; } +/* Parses build-id sections into the given destination. */ +static int parse_buildid(const struct livepatch_elf_sec *sec, + struct livepatch_build_id *id) +{ + const Elf_Note *n; + int rc; + + /* Presence of the sections is ensured by check_special_sections(). */ + ASSERT(sec); + + n = sec->load_addr; + + if ( sec->sec->sh_size <= sizeof(*n) ) + return -EINVAL; + + rc = xen_build_id_check(n, sec->sec->sh_size, &id->p, &id->len); + if ( rc ) + return rc; + + if ( !id->len || !id->p ) + return -EINVAL; + + return 0; +} + static int check_special_sections(const struct livepatch_elf *elf) { unsigned int i; @@ -641,11 +666,12 @@ static int prepare_payload(struct payload *payload, struct livepatch_elf *elf) { const struct livepatch_elf_sec *sec; + const struct payload *data; unsigned int i; struct livepatch_func *funcs; struct livepatch_func *f; struct virtual_region *region; - const Elf_Note *n; + int rc; sec = livepatch_elf_sec_by_name(elf, ELF_LIVEPATCH_FUNC); if ( sec ) @@ -663,8 +689,6 @@ static int prepare_payload(struct payload *payload, for ( i = 0; i < payload->nfuncs; i++ ) { - int rc; - f = &(funcs[i]); if ( f->version != LIVEPATCH_PAYLOAD_VERSION ) @@ -707,69 +731,35 @@ static int prepare_payload(struct payload *payload, LIVEPATCH_ASSIGN_SINGLE_HOOK(elf, payload->hooks.revert.action, ELF_LIVEPATCH_REVERT_HOOK); LIVEPATCH_ASSIGN_SINGLE_HOOK(elf, payload->hooks.revert.post, ELF_LIVEPATCH_POSTREVERT_HOOK); - sec = livepatch_elf_sec_by_name(elf, ELF_BUILD_ID_NOTE); - if ( sec ) - { - const struct payload *data; - - n = sec->load_addr; - - if ( sec->sec->sh_size <= sizeof(*n) ) - return -EINVAL; - - if ( xen_build_id_check(n, sec->sec->sh_size, - &payload->id.p, &payload->id.len) ) - return -EINVAL; - - if ( !payload->id.len || !payload->id.p ) - return -EINVAL; + rc = parse_buildid(livepatch_elf_sec_by_name(elf, ELF_BUILD_ID_NOTE), + &payload->id); + if ( rc ) + return rc; - /* Make sure it is not a duplicate. */ - list_for_each_entry ( data, &payload_list, list ) + /* Make sure it is not a duplicate. */ + list_for_each_entry ( data, &payload_list, list ) + { + /* No way _this_ payload is on the list. */ + ASSERT(data != payload); + if ( data->id.len == payload->id.len && + !memcmp(data->id.p, payload->id.p, data->id.len) ) { - /* No way _this_ payload is on the list. */ - ASSERT(data != payload); - if ( data->id.len == payload->id.len && - !memcmp(data->id.p, payload->id.p, data->id.len) ) - { - dprintk(XENLOG_DEBUG, LIVEPATCH "%s: Already loaded as %s!\n", - elf->name, data->name); - return -EEXIST; - } + dprintk(XENLOG_DEBUG, LIVEPATCH "%s: Already loaded as %s!\n", + elf->name, data->name); + return -EEXIST; } } - sec = livepatch_elf_sec_by_name(elf, ELF_LIVEPATCH_DEPENDS); - if ( sec ) - { - n = sec->load_addr; - - if ( sec->sec->sh_size <= sizeof(*n) ) - return -EINVAL; - - if ( xen_build_id_check(n, sec->sec->sh_size, - &payload->dep.p, &payload->dep.len) ) - return -EINVAL; - - if ( !payload->dep.len || !payload->dep.p ) - return -EINVAL; - } - - sec = livepatch_elf_sec_by_name(elf, ELF_LIVEPATCH_XEN_DEPENDS); - if ( sec ) - { - n = sec->load_addr; - - if ( sec->sec->sh_size <= sizeof(*n) ) - return -EINVAL; - - if ( xen_build_id_check(n, sec->sec->sh_size, - &payload->xen_dep.p, &payload->xen_dep.len) ) - return -EINVAL; + rc = parse_buildid(livepatch_elf_sec_by_name(elf, ELF_LIVEPATCH_DEPENDS), + &payload->dep); + if ( rc ) + return rc; - if ( !payload->xen_dep.len || !payload->xen_dep.p ) - return -EINVAL; - } + rc = parse_buildid(livepatch_elf_sec_by_name(elf, + ELF_LIVEPATCH_XEN_DEPENDS), + &payload->xen_dep); + if ( rc ) + return rc; /* Setup the virtual region with proper data. */ region = &payload->region; -- 2.46.0
|
Lists.xenproject.org is hosted with RackSpace, monitoring our |