From nobody Mon Apr 6 18:22:58 2026 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id DCA08390C8A; Wed, 18 Mar 2026 12:26:04 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773836764; cv=none; b=qgaWQsAUOKBy9ghFYurfSjVO/HwrOK/KjzVgMbUmbn4BrmKC4KN/z4ofW8YEowDa+j8NSG07HouloxsodAzmibtshPjsMrjeheH87BTL6O5boIMEd4qBraSIfnEpwiDjakt5Cz6HawVKadZDGPwdLOIZQD8uda2gsGMrycKx0kk= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773836764; c=relaxed/simple; bh=kASi/MXfva0PZj+CNVXfI6T0+wW0paeGZQt1qZxdvqc=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:To:Cc; b=RUEIHm4LlO65cd8IDBsMj8ACJEqHS29oz8wvL2B8zAauwp78LnR7MsebV2k7HP5HbT/7RfMC4EwsKd8JhPunFbLvW+0yK1bH+3Hg0Kg0RlJvamOHvFCEDFrmBQVhkZDmIRY6DRcZz9Reh+SZA4b5kDt4JVcSa8XNV2Dje4urUpc= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=N+hipnPh; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="N+hipnPh" Received: by smtp.kernel.org (Postfix) with ESMTPSA id AADBAC19421; Wed, 18 Mar 2026 12:26:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1773836764; bh=kASi/MXfva0PZj+CNVXfI6T0+wW0paeGZQt1qZxdvqc=; h=From:Date:Subject:To:Cc:From; b=N+hipnPhk0drdnLHVJogLRNgBGwdXblOf+TO7uLpgLfn/sy1A1fLVa0my//7XqgQk iB+9+ZB5prBbqjcH3BiydKoJsVQGRvm3aANcjqxmvVAU9rjeTINIliVNyC0Jgi+mTr 0vXG7sSrtrHMj1v23OK7H0WQ9y1DI2rj89QrbcvZn/x+55ZSny/61GkJUt/affu//c mv7wQDe0fw+CTI4EBKlFWqUM/zTQe5iiu+9bVpHbQA785V1xq7JdBMNLQ0Q4rvSHdO RN95D9b96/Jrm7mr0+laKtiUk9fvP9LooZuprw26tWjvhgpjdqvp5ZZCoSNtdNR8aW n0S93qsXWNj8Q== From: Jeff Layton Date: Wed, 18 Mar 2026 08:25:54 -0400 Subject: [PATCH] firmware_loader: allow firmware_class.path to take multiple paths Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Message-Id: <20260318-fw-path-v1-1-7884d9bf618f@kernel.org> X-B4-Tracking: v=1; b=H4sIAAAAAAAC/6tWKk4tykwtVrJSqFYqSi3LLM7MzwNyDHUUlJIzE vPSU3UzU4B8JSMDIzMDY0Nz3bRy3YLEkgzdRANLk2RjAyNTy0RTJaDqgqLUtMwKsEnRsbW1ABk 3pqZZAAAA X-Change-ID: 20260317-fw-path-a094c30259a5 To: Luis Chamberlain , Russ Weight , Danilo Krummrich , Greg Kroah-Hartman , "Rafael J. Wysocki" Cc: Michal Grzedzicki , driver-core@lists.linux.dev, linux-kernel@vger.kernel.org, Jeff Layton X-Mailer: b4 0.14.2 X-Developer-Signature: v=1; a=openpgp-sha256; l=7810; i=jlayton@kernel.org; h=from:subject:message-id; bh=kASi/MXfva0PZj+CNVXfI6T0+wW0paeGZQt1qZxdvqc=; b=owEBbQKS/ZANAwAKAQAOaEEZVoIVAcsmYgBpupnWAtOsF2WG0H5DnYvAQTiQotl7bbKW9HE+y K7/+khP+ACJAjMEAAEKAB0WIQRLwNeyRHGyoYTq9dMADmhBGVaCFQUCabqZ1gAKCRAADmhBGVaC Fd9KD/wLwMvAIc6o8h/fxBmRrJy6XlfgAaPCO//qWUmCb1RBnGxf99Lz4rHHuiiXxWtrD8pYuUc SC380QaQbreG73/eOUBN17QdxammckCVVM5t1jRr7ajWRpBsm8vnmNsrdWKFgeMkbEDKPc93157 LDHiwEV1XlvyZoGnuum2Pqvgujn4/Uan7iVr8BeXHnvswc6MZ+QVxINNkkHfNm9oDP5bxWiVu1S gCg35bQv7d5CX0gFbBg3TjMdMYVwmvxR06S8nk2LG9O5d3I1dfKWouP8CT50jwfn2pVgfCRS73j hrKb+/InXdJ8BrtipBg0p9nDA0Rou/B0tXlx/0TP9eAdD9RwDuX3hQJqzz+GvOcI6MtC3/ikp6k dT9YxNWADt4AJDhT7fGhXEOUWhLrr1VqjsQuLoTkpk8P6V13ctDD+OxJVd1wNJKz8AuCw3nL+Qk 3iu0dSUgu8gioCS3OKE8G2s74zMFp1XmzdSyli7ycYnVHb/09cOvvxiF06dXBbO4UQfYsy0ehOe F88lONm/ibESkk2xo2mZMNXl+HvLiI0duSUPsIA3SGuONpGeE/THMthsDGnGG/5He1xdV1boUvH UHBBUtGPFBrQlwvYeTw+ybq99iIGALQQ0RdBbG+bonJRNPPZqdiWi7NcLyu+LGZBf3+Vo1AB+Iv hBMVdoirLhPhkWQ== X-Developer-Key: i=jlayton@kernel.org; a=openpgp; fpr=4BC0D7B24471B2A184EAF5D3000E684119568215 Refactor fw_get_filesystem_firmware() by extracting the per-path firmware loading logic into a new fw_try_firmware_path() helper. Use this helper to parse fw_path_para for ';'-separated paths, trying each one before falling through to the default firmware search paths. This allows users to specify multiple custom firmware directories via firmware_class.path, e.g.: firmware_class.path=3D/custom/path1;/custom/path2 Suggested-by: Michal Grzedzicki Signed-off-by: Jeff Layton --- This is something Michal had asked for last year, and I just got around to implementing. Tested with a dummy module that calls request_firmware(). --- drivers/base/firmware_loader/main.c | 197 +++++++++++++++++++++-----------= ---- 1 file changed, 118 insertions(+), 79 deletions(-) diff --git a/drivers/base/firmware_loader/main.c b/drivers/base/firmware_lo= ader/main.c index a11b30dda23be563bd55f25474ceff2153ddd667..5328d28a2141e85265e1bcc20e9= 95ce4c5517c36 100644 --- a/drivers/base/firmware_loader/main.c +++ b/drivers/base/firmware_loader/main.c @@ -470,7 +470,6 @@ static int fw_decompress_xz(struct device *dev, struct = fw_priv *fw_priv, /* direct firmware loading support */ static char fw_path_para[256]; static const char * const fw_path[] =3D { - fw_path_para, "/lib/firmware/updates/" UTS_RELEASE, "/lib/firmware/updates", "/lib/firmware/" UTS_RELEASE, @@ -480,10 +479,83 @@ static const char * const fw_path[] =3D { /* * Typical usage is that passing 'firmware_class.path=3D$CUSTOMIZED_PATH' * from kernel command line because firmware_class is generally built in - * kernel instead of module. + * kernel instead of module. Multiple paths can be separated by ';'. */ module_param_string(path, fw_path_para, sizeof(fw_path_para), 0644); -MODULE_PARM_DESC(path, "customized firmware image search path with a highe= r priority than default path"); +MODULE_PARM_DESC(path, "customized firmware image search path with a highe= r priority than default path, multiple paths can be separated by ';'"); + +static int +fw_try_firmware_path(struct device *device, struct fw_priv *fw_priv, + const char *suffix, + int (*decompress)(struct device *dev, + struct fw_priv *fw_priv, + size_t in_size, + const void *in_buffer), + const char *dir, int dirlen, + char *path, void **bufp, size_t msize) +{ + size_t file_size =3D 0; + size_t *file_size_ptr =3D NULL; + size_t size; + int len, rc; + + len =3D snprintf(path, PATH_MAX, "%.*s/%s%s", + dirlen, dir, fw_priv->fw_name, suffix); + if (len >=3D PATH_MAX) + return -ENAMETOOLONG; + + fw_priv->size =3D 0; + + /* + * The total file size is only examined when doing a partial + * read; the "full read" case needs to fail if the whole + * firmware was not completely loaded. + */ + if ((fw_priv->opt_flags & FW_OPT_PARTIAL) && *bufp) + file_size_ptr =3D &file_size; + + /* load firmware files from the mount namespace of init */ + rc =3D kernel_read_file_from_path_initns(path, fw_priv->offset, + bufp, msize, + file_size_ptr, + READING_FIRMWARE); + if (rc < 0) { + if (!(fw_priv->opt_flags & FW_OPT_NO_WARN)) { + if (rc !=3D -ENOENT) + dev_warn(device, + "loading %s failed with error %d\n", + path, rc); + else + dev_dbg(device, + "loading %s failed for no such file or directory.\n", + path); + } + return rc; + } + size =3D rc; + + dev_dbg(device, "Loading firmware from %s\n", path); + if (decompress) { + dev_dbg(device, "f/w decompressing %s\n", + fw_priv->fw_name); + rc =3D decompress(device, fw_priv, size, *bufp); + /* discard the superfluous original content */ + vfree(*bufp); + *bufp =3D NULL; + if (rc) { + fw_free_paged_buf(fw_priv); + return rc; + } + } else { + dev_dbg(device, "direct-loading %s\n", + fw_priv->fw_name); + if (!fw_priv->data) + fw_priv->data =3D *bufp; + fw_priv->size =3D size; + } + fw_state_done(fw_priv); + return 0; +} =20 static int fw_get_filesystem_firmware(struct device *device, struct fw_priv *fw_priv, @@ -493,10 +565,9 @@ fw_get_filesystem_firmware(struct device *device, stru= ct fw_priv *fw_priv, size_t in_size, const void *in_buffer)) { - size_t size; - int i, len, maxlen =3D 0; + int i; int rc =3D -ENOENT; - char *path, *nt =3D NULL; + char *path; size_t msize =3D INT_MAX; void *buffer =3D NULL; =20 @@ -511,83 +582,51 @@ fw_get_filesystem_firmware(struct device *device, str= uct fw_priv *fw_priv, return -ENOMEM; =20 wait_for_initramfs(); - for (i =3D 0; i < ARRAY_SIZE(fw_path); i++) { - size_t file_size =3D 0; - size_t *file_size_ptr =3D NULL; - - /* skip the unset customized path */ - if (!fw_path[i][0]) - continue; - - /* strip off \n from customized path */ - maxlen =3D strlen(fw_path[i]); - if (i =3D=3D 0) { - nt =3D strchr(fw_path[i], '\n'); - if (nt) - maxlen =3D nt - fw_path[i]; - } - - len =3D snprintf(path, PATH_MAX, "%.*s/%s%s", - maxlen, fw_path[i], - fw_priv->fw_name, suffix); - if (len >=3D PATH_MAX) { - rc =3D -ENAMETOOLONG; - break; - } =20 - fw_priv->size =3D 0; - - /* - * The total file size is only examined when doing a partial - * read; the "full read" case needs to fail if the whole - * firmware was not completely loaded. - */ - if ((fw_priv->opt_flags & FW_OPT_PARTIAL) && buffer) - file_size_ptr =3D &file_size; - - /* load firmware files from the mount namespace of init */ - rc =3D kernel_read_file_from_path_initns(path, fw_priv->offset, - &buffer, msize, - file_size_ptr, - READING_FIRMWARE); - if (rc < 0) { - if (!(fw_priv->opt_flags & FW_OPT_NO_WARN)) { - if (rc !=3D -ENOENT) - dev_warn(device, - "loading %s failed with error %d\n", - path, rc); - else - dev_dbg(device, - "loading %s failed for no such file or directory.\n", - path); - } - continue; - } - size =3D rc; - rc =3D 0; - - dev_dbg(device, "Loading firmware from %s\n", path); - if (decompress) { - dev_dbg(device, "f/w decompressing %s\n", - fw_priv->fw_name); - rc =3D decompress(device, fw_priv, size, buffer); - /* discard the superfluous original content */ - vfree(buffer); - buffer =3D NULL; - if (rc) { - fw_free_paged_buf(fw_priv); - continue; + /* Try each ';'-separated path in fw_path_para first */ + if (fw_path_para[0]) { + const char *start =3D fw_path_para; + const char *end; + + while (*start) { + int dirlen; + + end =3D strchr(start, ';'); + if (end) + dirlen =3D end - start; + else + dirlen =3D strlen(start); + + /* strip trailing newline */ + if (dirlen > 0 && start[dirlen - 1] =3D=3D '\n') + dirlen--; + + if (dirlen > 0) { + rc =3D fw_try_firmware_path(device, fw_priv, + suffix, decompress, + start, dirlen, + path, &buffer, + msize); + if (!rc) + goto done; } - } else { - dev_dbg(device, "direct-loading %s\n", - fw_priv->fw_name); - if (!fw_priv->data) - fw_priv->data =3D buffer; - fw_priv->size =3D size; + + if (!end) + break; + start =3D end + 1; } - fw_state_done(fw_priv); - break; } + + /* Try default firmware paths */ + for (i =3D 0; i < ARRAY_SIZE(fw_path); i++) { + rc =3D fw_try_firmware_path(device, fw_priv, suffix, decompress, + fw_path[i], strlen(fw_path[i]), + path, &buffer, msize); + if (!rc) + break; + } + +done: __putname(path); =20 return rc; --- base-commit: 2d1373e4246da3b58e1df058374ed6b101804e07 change-id: 20260317-fw-path-a094c30259a5 Best regards, --=20 Jeff Layton