From df326e7a06990bab011afc8c17de1ab2774e4bb8 Mon Sep 17 00:00:00 2001 From: Mike Snitzer Date: Tue, 26 Jul 2022 11:29:50 -0400 Subject: [PATCH] dm verity: allow optional args to alter primary args handling The previous commit ("dm verity: Add optional "try_verify_in_tasklet" feature") imposed that CRYPTO_ALG_ASYNC mask be used even if the optional "try_verify_in_tasklet" feature was not specified. This was because verity_parse_opt_args() was called after handling the primary args (due to it having data dependencies on having first parsed all primary args). Enhance verity_ctr() so that simple optional args, that don't have a data dependency on primary args parsing, can alter how the primary args are handled. In practice this means verity_parse_opt_args() gets called twice. First with the new 'only_modifier_opts' arg set to true, then again with it set to false _after_ parsing all primary args. This allows the v->use_tasklet flag to be properly set and then used when verity_ctr() parses the primary args and then calls crypto_alloc_ahash() with CRYPTO_ALG_ASYNC conditionally set. Signed-off-by: Mike Snitzer --- drivers/md/dm-verity-target.c | 32 ++++++++++++++++++++++++-------- 1 file changed, 24 insertions(+), 8 deletions(-) diff --git a/drivers/md/dm-verity-target.c b/drivers/md/dm-verity-target.c index 44af4fa..4895d6b 100644 --- a/drivers/md/dm-verity-target.c +++ b/drivers/md/dm-verity-target.c @@ -1027,7 +1027,8 @@ static int verity_parse_verity_mode(struct dm_verity *v, const char *arg_name) } static int verity_parse_opt_args(struct dm_arg_set *as, struct dm_verity *v, - struct dm_verity_sig_opts *verify_args) + struct dm_verity_sig_opts *verify_args, + bool only_modifier_opts) { int r; unsigned argc; @@ -1050,6 +1051,8 @@ static int verity_parse_opt_args(struct dm_arg_set *as, struct dm_verity *v, argc--; if (verity_is_verity_mode(arg_name)) { + if (only_modifier_opts) + continue; r = verity_parse_verity_mode(v, arg_name); if (r) { ti->error = "Conflicting error handling parameters"; @@ -1058,6 +1061,8 @@ static int verity_parse_opt_args(struct dm_arg_set *as, struct dm_verity *v, continue; } else if (!strcasecmp(arg_name, DM_VERITY_OPT_IGN_ZEROES)) { + if (only_modifier_opts) + continue; r = verity_alloc_zero_digest(v); if (r) { ti->error = "Cannot allocate zero digest"; @@ -1066,6 +1071,8 @@ static int verity_parse_opt_args(struct dm_arg_set *as, struct dm_verity *v, continue; } else if (!strcasecmp(arg_name, DM_VERITY_OPT_AT_MOST_ONCE)) { + if (only_modifier_opts) + continue; r = verity_alloc_most_once(v); if (r) return r; @@ -1076,12 +1083,16 @@ static int verity_parse_opt_args(struct dm_arg_set *as, struct dm_verity *v, continue; } else if (verity_is_fec_opt_arg(arg_name)) { + if (only_modifier_opts) + continue; r = verity_fec_parse_opt_args(as, v, &argc, arg_name); if (r) return r; continue; } else if (verity_verify_is_sig_opt_arg(arg_name)) { + if (only_modifier_opts) + continue; r = verity_verify_sig_parse_opt_args(as, v, verify_args, &argc, arg_name); @@ -1148,6 +1159,15 @@ static int verity_ctr(struct dm_target *ti, unsigned argc, char **argv) goto bad; } + /* Parse optional parameters that modify primary args */ + if (argc > 10) { + as.argc = argc - 10; + as.argv = argv + 10; + r = verity_parse_opt_args(&as, v, &verify_args, true); + if (r < 0) + goto bad; + } + if (sscanf(argv[0], "%u%c", &num, &dummy) != 1 || num > 1) { ti->error = "Invalid version"; @@ -1219,11 +1239,8 @@ static int verity_ctr(struct dm_target *ti, unsigned argc, char **argv) goto bad; } - /* - * FIXME: CRYPTO_ALG_ASYNC should be conditional on v->use_tasklet - * but verity_parse_opt_args() happens below and has data dep on tfm. - */ - v->tfm = crypto_alloc_ahash(v->alg_name, 0, CRYPTO_ALG_ASYNC); + v->tfm = crypto_alloc_ahash(v->alg_name, 0, + v->use_tasklet ? CRYPTO_ALG_ASYNC : 0); if (IS_ERR(v->tfm)) { ti->error = "Cannot initialize hash function"; r = PTR_ERR(v->tfm); @@ -1285,8 +1302,7 @@ static int verity_ctr(struct dm_target *ti, unsigned argc, char **argv) if (argc) { as.argc = argc; as.argv = argv; - - r = verity_parse_opt_args(&as, v, &verify_args); + r = verity_parse_opt_args(&as, v, &verify_args, false); if (r < 0) goto bad; } -- 2.7.4