diff --git a/docs/misc/livepatch.pandoc b/docs/misc/livepatch.pandoc index 4f9238d235..43d0896aa8 100644 --- a/docs/misc/livepatch.pandoc +++ b/docs/misc/livepatch.pandoc @@ -717,17 +717,19 @@ The caller provides: * `idx` Index iterator. The index into the hypervisor's payload count. It is recommended that on first invocation zero be used so that `nr` (which the hypervisor will update with the remaining payload count) be provided. - Also the hypervisor will provide `version` with the most current value. + Also the hypervisor will provide `version` with the most current value and + calculated total size for all payloads' names. * `nr` The max number of entries to populate. Can be zero which will result in the hypercall being a probing one and return the number of payloads (and update the `version`). - * `pad` - *MUST* be zero. * `status` Virtual address of where to write `struct xen_livepatch_status` structures. Caller *MUST* allocate up to `nr` of them. - * `name` - Virtual address of where to write the unique name of the payload. - Caller *MUST* allocate up to `nr` of them. Each *MUST* be of - **XEN_LIVEPATCH_NAME_SIZE** size. Note that **XEN_LIVEPATCH_NAME_SIZE** includes - the NUL terminator. + * `name` - Virtual address of where to write the unique name of the payloads. + Caller *MUST* allocate enough space to be able to store all received data + (i.e. total allocated space *MUST* match the `name_total_size` value + provided by the hypervisor). Individual payload name cannot be longer than + **XEN_LIVEPATCH_NAME_SIZE** bytes. Note that **XEN_LIVEPATCH_NAME_SIZE** + includes the NUL terminator. * `len` - Virtual address of where to write the length of each unique name of the payload. Caller *MUST* allocate up to `nr` of them. Each *MUST* be of sizeof(uint32_t) (4 bytes). @@ -736,7 +738,8 @@ If the hypercall returns an positive number, it is the number (upto `nr` provided to the hypercall) of the payloads returned, along with `nr` updated with the number of remaining payloads, `version` updated (it may be the same across hypercalls - if it varies the data is stale and further calls could -fail). The `status`, `name`, and `len` are updated at their designed index +fail) and the `name_total_size` containing total size of transferred data for +the array. The `status`, `name`, and `len` are updated at their designed index value (`idx`) with the returned value of data. If the hypercall returns -XEN_E2BIG the `nr` is too big and should be @@ -774,12 +777,13 @@ The structure is as follow: should be filled out. Can be zero to get amount of payloads and version. OUT: How many payloads left. */ - uint32_t pad; /* IN: Must be zero. */ + uint32_t name_total_size; /* OUT: Total size of all transfer names */ XEN_GUEST_HANDLE_64(xen_livepatch_status_t) status; /* OUT. Must have enough space allocate for nr of them. */ - XEN_GUEST_HANDLE_64(char) id; /* OUT: Array of names. Each member - MUST XEN_LIVEPATCH_NAME_SIZE in size. - Must have nr of them. */ + XEN_GUEST_HANDLE_64(char) name; /* OUT: Array of names. Each member + may have an arbitrary length up to + XEN_LIVEPATCH_NAME_SIZE bytes. Must have + nr of them. */ XEN_GUEST_HANDLE_64(uint32) len; /* OUT: Array of lengths of name's. Must have nr of them. */ }; diff --git a/tools/libxc/include/xenctrl.h b/tools/libxc/include/xenctrl.h index b06738c471..f490a6debc 100644 --- a/tools/libxc/include/xenctrl.h +++ b/tools/libxc/include/xenctrl.h @@ -2558,7 +2558,25 @@ int xc_livepatch_get(xc_interface *xch, xen_livepatch_status_t *status); /* - * The heart of this function is to get an array of xen_livepatch_status_t. + * Get a number of available payloads and get actual total size of + * the payloads' name array. + * + * This functions is typically executed first before the xc_livepatch_list() + * to obtain the sizes and correctly allocate all necessary data resources. + * + * The return value is zero if the hypercall completed successfully. + * + * If there was an error performing the sysctl operation, the return value + * will contain the hypercall error code value. + */ +int xc_livepatch_list_get_sizes(xc_interface *xch, unsigned int *nr, + uint32_t *name_total_size); + +/* + * The heart of this function is to get an array of the following objects: + * - xen_livepatch_status_t: states and return codes of payloads + * - name: names of payloads + * - len: lengths of corresponding payloads' names * * However it is complex because it has to deal with the hypervisor * returning some of the requested data or data being stale @@ -2569,21 +2587,20 @@ int xc_livepatch_get(xc_interface *xch, * 'left' are also updated with the number of entries filled out * and respectively the number of entries left to get from hypervisor. * - * It is expected that the caller of this function will take the - * 'left' and use the value for 'start'. This way we have an - * cursor in the array. Note that the 'info','name', and 'len' will - * be updated at the subsequent calls. + * It is expected that the caller of this function will first issue the + * xc_livepatch_list_get_sizes() in order to obtain total sizes of names + * as well as the current number of payload entries. + * The total sizes are required and supplied via the 'name_total_size' + * parameter. * - * The 'max' is to be provided by the caller with the maximum - * number of entries that 'info', 'name', and 'len' arrays can - * be filled up with. - * - * Each entry in the 'name' array is expected to be of XEN_LIVEPATCH_NAME_SIZE - * length. + * The 'max' is to be provided by the caller with the maximum number of + * entries that 'info', 'name', 'len' arrays can be filled up with. * * Each entry in the 'info' array is expected to be of xen_livepatch_status_t * structure size. * + * Each entry in the 'name' array may have an arbitrary size. + * * Each entry in the 'len' array is expected to be of uint32_t size. * * The return value is zero if the hypercall completed successfully. @@ -2595,10 +2612,12 @@ int xc_livepatch_get(xc_interface *xch, * will contain the number of entries that had been succesfully * retrieved (if any). */ -int xc_livepatch_list(xc_interface *xch, unsigned int max, unsigned int start, - xen_livepatch_status_t *info, char *name, - uint32_t *len, unsigned int *done, - unsigned int *left); +int xc_livepatch_list(xc_interface *xch, const unsigned int max, + const unsigned int start, + struct xen_livepatch_status *info, + char *name, uint32_t *len, + const uint32_t name_total_size, + unsigned int *done, unsigned int *left); /* * The operations are asynchronous and the hypervisor may take a while diff --git a/tools/libxc/xc_misc.c b/tools/libxc/xc_misc.c index 336580135e..580d254593 100644 --- a/tools/libxc/xc_misc.c +++ b/tools/libxc/xc_misc.c @@ -662,7 +662,48 @@ int xc_livepatch_get(xc_interface *xch, } /* - * The heart of this function is to get an array of xen_livepatch_status_t. + * Get a number of available payloads and get actual total size of + * the payloads' name array. + * + * This functions is typically executed first before the xc_livepatch_list() + * to obtain the sizes and correctly allocate all necessary data resources. + * + * The return value is zero if the hypercall completed successfully. + * + * If there was an error performing the sysctl operation, the return value + * will contain the hypercall error code value. + */ +int xc_livepatch_list_get_sizes(xc_interface *xch, unsigned int *nr, + uint32_t *name_total_size) +{ + DECLARE_SYSCTL; + int rc; + + if ( !nr || !name_total_size ) + { + errno = EINVAL; + return -1; + } + + memset(&sysctl, 0, sizeof(sysctl)); + sysctl.cmd = XEN_SYSCTL_livepatch_op; + sysctl.u.livepatch.cmd = XEN_SYSCTL_LIVEPATCH_LIST; + + rc = do_sysctl(xch, &sysctl); + if ( rc ) + return rc; + + *nr = sysctl.u.livepatch.u.list.nr; + *name_total_size = sysctl.u.livepatch.u.list.name_total_size; + + return 0; +} + +/* + * The heart of this function is to get an array of the following objects: + * - xen_livepatch_status_t: states and return codes of payloads + * - name: names of payloads + * - len: lengths of corresponding payloads' names * * However it is complex because it has to deal with the hypervisor * returning some of the requested data or data being stale @@ -673,21 +714,20 @@ int xc_livepatch_get(xc_interface *xch, * 'left' are also updated with the number of entries filled out * and respectively the number of entries left to get from hypervisor. * - * It is expected that the caller of this function will take the - * 'left' and use the value for 'start'. This way we have an - * cursor in the array. Note that the 'info','name', and 'len' will - * be updated at the subsequent calls. + * It is expected that the caller of this function will first issue the + * xc_livepatch_list_get_sizes() in order to obtain total sizes of names + * as well as the current number of payload entries. + * The total sizes are required and supplied via the 'name_total_size' + * parameter. * - * The 'max' is to be provided by the caller with the maximum - * number of entries that 'info', 'name', and 'len' arrays can - * be filled up with. - * - * Each entry in the 'name' array is expected to be of XEN_LIVEPATCH_NAME_SIZE - * length. + * The 'max' is to be provided by the caller with the maximum number of + * entries that 'info', 'name', 'len' arrays can be filled up with. * * Each entry in the 'info' array is expected to be of xen_livepatch_status_t * structure size. * + * Each entry in the 'name' array may have an arbitrary size. + * * Each entry in the 'len' array is expected to be of uint32_t size. * * The return value is zero if the hypercall completed successfully. @@ -699,11 +739,12 @@ int xc_livepatch_get(xc_interface *xch, * will contain the number of entries that had been succesfully * retrieved (if any). */ -int xc_livepatch_list(xc_interface *xch, unsigned int max, unsigned int start, +int xc_livepatch_list(xc_interface *xch, const unsigned int max, + const unsigned int start, struct xen_livepatch_status *info, char *name, uint32_t *len, - unsigned int *done, - unsigned int *left) + const uint32_t name_total_size, + unsigned int *done, unsigned int *left) { int rc; DECLARE_SYSCTL; @@ -714,27 +755,33 @@ int xc_livepatch_list(xc_interface *xch, unsigned int max, unsigned int start, uint32_t max_batch_sz, nr; uint32_t version = 0, retries = 0; uint32_t adjust = 0; - ssize_t sz; + uint32_t name_off = 0; + uint32_t name_sz; - if ( !max || !info || !name || !len ) + if ( !max || !info || !name || !len || !done || !left ) { errno = EINVAL; return -1; } + if ( name_total_size == 0 ) + { + errno = ENOENT; + return -1; + } + + memset(&sysctl, 0, sizeof(sysctl)); sysctl.cmd = XEN_SYSCTL_livepatch_op; sysctl.u.livepatch.cmd = XEN_SYSCTL_LIVEPATCH_LIST; - sysctl.u.livepatch.pad = 0; - sysctl.u.livepatch.u.list.version = 0; sysctl.u.livepatch.u.list.idx = start; - sysctl.u.livepatch.u.list.pad = 0; max_batch_sz = max; - /* Convience value. */ - sz = sizeof(*name) * XEN_LIVEPATCH_NAME_SIZE; + name_sz = name_total_size; *done = 0; *left = 0; do { + uint32_t _name_sz; + /* * The first time we go in this loop our 'max' may be bigger * than what the hypervisor is comfortable with - hence the first @@ -754,11 +801,11 @@ int xc_livepatch_list(xc_interface *xch, unsigned int max, unsigned int start, sysctl.u.livepatch.u.list.nr = nr; /* Fix the size (may vary between hypercalls). */ HYPERCALL_BOUNCE_SET_SIZE(info, nr * sizeof(*info)); - HYPERCALL_BOUNCE_SET_SIZE(name, nr * nr); + HYPERCALL_BOUNCE_SET_SIZE(name, name_sz); HYPERCALL_BOUNCE_SET_SIZE(len, nr * sizeof(*len)); /* Move the pointer to proper offset into 'info'. */ (HYPERCALL_BUFFER(info))->ubuf = info + *done; - (HYPERCALL_BUFFER(name))->ubuf = name + (sz * *done); + (HYPERCALL_BUFFER(name))->ubuf = name + name_off; (HYPERCALL_BUFFER(len))->ubuf = len + *done; /* Allocate memory. */ rc = xc_hypercall_bounce_pre(xch, info); @@ -827,14 +874,19 @@ int xc_livepatch_list(xc_interface *xch, unsigned int max, unsigned int start, break; } *left = sysctl.u.livepatch.u.list.nr; /* Total remaining count. */ + _name_sz = sysctl.u.livepatch.u.list.name_total_size; /* Total received name size. */ /* Copy only up 'rc' of data' - we could add 'min(rc,nr) if desired. */ HYPERCALL_BOUNCE_SET_SIZE(info, (rc * sizeof(*info))); - HYPERCALL_BOUNCE_SET_SIZE(name, (rc * sz)); + HYPERCALL_BOUNCE_SET_SIZE(name, _name_sz); HYPERCALL_BOUNCE_SET_SIZE(len, (rc * sizeof(*len))); /* Bounce the data and free the bounce buffer. */ xc_hypercall_bounce_post(xch, info); xc_hypercall_bounce_post(xch, name); xc_hypercall_bounce_post(xch, len); + + name_sz -= _name_sz; + name_off += _name_sz; + /* And update how many elements of info we have copied into. */ *done += rc; /* Update idx. */ diff --git a/tools/misc/xen-livepatch.c b/tools/misc/xen-livepatch.c index b469b253ad..c93c50040c 100644 --- a/tools/misc/xen-livepatch.c +++ b/tools/misc/xen-livepatch.c @@ -64,14 +64,13 @@ static const char *state2str(unsigned int state) return names[state]; } -/* This value was choosen adhoc. It could be 42 too. */ -#define MAX_LEN 11 static int list_func(int argc, char *argv[]) { - unsigned int idx, done, left, i; + unsigned int nr, done, left, i; xen_livepatch_status_t *info = NULL; char *name = NULL; uint32_t *len = NULL; + uint32_t name_total_size, name_off; int rc = ENOMEM; if ( argc ) @@ -79,65 +78,73 @@ static int list_func(int argc, char *argv[]) show_help(); return -1; } - idx = left = 0; - info = malloc(sizeof(*info) * MAX_LEN); + done = left = 0; + + rc = xc_livepatch_list_get_sizes(xch, &nr, &name_total_size); + if ( rc ) + { + rc = errno; + fprintf(stderr, "Failed to get list sizes.\n" + "Error %d: %s\n", + rc, strerror(rc)); + return rc; + } + + if ( nr == 0 ) + { + fprintf(stdout, "Nothing to list\n"); + return 0; + } + + info = malloc(nr * sizeof(*info)); if ( !info ) return rc; - name = malloc(sizeof(*name) * XEN_LIVEPATCH_NAME_SIZE * MAX_LEN); + + name = malloc(name_total_size * sizeof(*name)); if ( !name ) + goto error_name; + + len = malloc(nr * sizeof(*len)); + if ( !len ) + goto error_len; + + memset(info, 'A', nr * sizeof(*info)); + memset(name, 'B', name_total_size * sizeof(*name)); + memset(len, 'C', nr * sizeof(*len)); + name_off = 0; + + rc = xc_livepatch_list(xch, nr, 0, info, name, len, name_total_size, &done, &left); + if ( rc || done != nr || left > 0) { - free(info); - return rc; - } - len = malloc(sizeof(*len) * MAX_LEN); - if ( !len ) { - free(name); - free(info); - return rc; + rc = errno; + fprintf(stderr, "Failed to list %d/%d.\n" + "Error %d: %s\n", + left, nr, rc, strerror(rc)); + goto error; } - do { - done = 0; - /* The memset is done to catch errors. */ - memset(info, 'A', sizeof(*info) * MAX_LEN); - memset(name, 'B', sizeof(*name) * MAX_LEN * XEN_LIVEPATCH_NAME_SIZE); - memset(len, 'C', sizeof(*len) * MAX_LEN); - rc = xc_livepatch_list(xch, MAX_LEN, idx, info, name, len, &done, &left); - if ( rc ) - { - rc = errno; - fprintf(stderr, "Failed to list %d/%d.\n" - "Error %d: %s\n", - idx, left, rc, strerror(rc)); - break; - } - if ( !idx ) - fprintf(stdout," ID | status\n" - "----------------------------------------+------------\n"); + fprintf(stdout," ID | status\n" + "----------------------------------------+------------\n"); - for ( i = 0; i < done; i++ ) - { - unsigned int j; - uint32_t sz; - char *str; + for ( i = 0; i < done; i++ ) + { + char *name_str = name + name_off; - sz = len[i]; - str = name + (i * XEN_LIVEPATCH_NAME_SIZE); - for ( j = sz; j < XEN_LIVEPATCH_NAME_SIZE; j++ ) - str[j] = '\0'; + printf("%-40.*s| %s", len[i], name_str, state2str(info[i].state)); + if ( info[i].rc ) + printf(" (%d, %s)\n", -info[i].rc, strerror(-info[i].rc)); + else + puts(""); - printf("%-40s| %s", str, state2str(info[i].state)); - if ( info[i].rc ) - printf(" (%d, %s)\n", -info[i].rc, strerror(-info[i].rc)); - else - puts(""); - } - idx += done; - } while ( left ); + name_off += len[i]; + } - free(name); - free(info); +error: free(len); +error_len: + free(name); +error_name: + free(info); return rc; } #undef MAX_LEN diff --git a/xen/common/livepatch.c b/xen/common/livepatch.c index 133f58bcf2..bc643295d6 100644 --- a/xen/common/livepatch.c +++ b/xen/common/livepatch.c @@ -1159,12 +1159,8 @@ static int livepatch_list(struct xen_sysctl_livepatch_list *list) if ( list->nr > 1024 ) return -E2BIG; - if ( list->pad ) - return -EINVAL; - if ( list->nr && (!guest_handle_okay(list->status, list->nr) || - !guest_handle_okay(list->name, XEN_LIVEPATCH_NAME_SIZE * list->nr) || !guest_handle_okay(list->len, list->nr)) ) return -EINVAL; @@ -1175,23 +1171,35 @@ static int livepatch_list(struct xen_sysctl_livepatch_list *list) return -EINVAL; } + list->name_total_size = 0; if ( list->nr ) { + uint64_t name_offset = 0; + list_for_each_entry( data, &payload_list, list ) { - uint32_t len; + uint32_t name_len; if ( list->idx > i++ ) continue; status.state = data->state; status.rc = data->rc; - len = strlen(data->name) + 1; + + name_len = strlen(data->name) + 1; + list->name_total_size += name_len; + + if ( !guest_handle_subrange_okay(list->name, name_offset, + name_offset + name_len - 1) ) + { + rc = -EINVAL; + break; + } /* N.B. 'idx' != 'i'. */ - if ( __copy_to_guest_offset(list->name, idx * XEN_LIVEPATCH_NAME_SIZE, - data->name, len) || - __copy_to_guest_offset(list->len, idx, &len, 1) || + if ( __copy_to_guest_offset(list->name, name_offset, + data->name, name_len) || + __copy_to_guest_offset(list->len, idx, &name_len, 1) || __copy_to_guest_offset(list->status, idx, &status, 1) ) { rc = -EFAULT; @@ -1199,11 +1207,19 @@ static int livepatch_list(struct xen_sysctl_livepatch_list *list) } idx++; + name_offset += name_len; if ( (idx >= list->nr) || hypercall_preempt_check() ) break; } } + else + { + list_for_each_entry( data, &payload_list, list ) + { + list->name_total_size += strlen(data->name) + 1; + } + } list->nr = payload_cnt - i; /* Remaining amount. */ list->version = payload_version; spin_unlock(&payload_lock); diff --git a/xen/include/public/sysctl.h b/xen/include/public/sysctl.h index ec6f16f0e6..4bfd1475bf 100644 --- a/xen/include/public/sysctl.h +++ b/xen/include/public/sysctl.h @@ -939,10 +939,11 @@ struct xen_sysctl_livepatch_get { * * If the hypercall returns an positive number, it is the number (up to `nr`) * of the payloads returned, along with `nr` updated with the number of remaining - * payloads, `version` updated (it may be the same across hypercalls. If it - * varies the data is stale and further calls could fail). The `status`, - * `name`, and `len`' are updated at their designed index value (`idx`) with - * the returned value of data. + * payloads, `version` updated (it may be the same across hypercalls. If it varies + * the data is stale and further calls could fail) and the name_total_size + * containing total size of transferred data for the array. + * The `status`, `name`, `len` are updated at their designed index value (`idx`) + * with the returned value of data. * * If the hypercall returns E2BIG the `nr` is too big and should be * lowered. The upper limit of `nr` is left to the implemention. @@ -964,12 +965,13 @@ struct xen_sysctl_livepatch_list { should fill out. Can be zero to get amount of payloads and version. OUT: How many payloads left. */ - uint32_t pad; /* IN: Must be zero. */ + uint32_t name_total_size; /* OUT: Total size of all transfer names */ XEN_GUEST_HANDLE_64(xen_livepatch_status_t) status; /* OUT. Must have enough space allocate for nr of them. */ XEN_GUEST_HANDLE_64(char) name; /* OUT: Array of names. Each member - MUST XEN_LIVEPATCH_NAME_SIZE in size. - Must have nr of them. */ + may have an arbitrary length up to + XEN_LIVEPATCH_NAME_SIZE bytes. Must have + nr of them. */ XEN_GUEST_HANDLE_64(uint32) len; /* OUT: Array of lengths of name's. Must have nr of them. */ };