From nobody Sat Apr 4 04:43:37 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 24BCD282F1F; Fri, 20 Mar 2026 15:32:40 +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=1774020761; cv=none; b=TQKM8QctW3Fp8xfQ0wETRQJP9X8LbHf37rZMLRKpf6R7pHlaz2Md5Qd7lZ2TZWlrE3qHf/Jkl3sKo1zYDw8dbHdhsD0aFV51ACeDnj1zPR3+u/QdfZRxiUQ/P9675CTb+UN+nmylDtzJy66KpKrVJFf4exSzvaXtJJeqvI09mKM= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774020761; c=relaxed/simple; bh=JQFqRpWHzUfYayHmC0f4Lwr06zQPEuXP1xsc57AEVTo=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:To:Cc; b=O9g5DsgyFue/mA1jKcEK6fJb2u+UkOu0LPNMyXgGf24FKXzvDw7+Z2gY+G40kwdL/+D2uisyLVuV9nIXO6o6IxRFEj/S/1a0WJ8c67MUQ+Bznpo3SlXejRVVN5+Q9m1+x8/tTNfAFVxYvozopdBs29c9UHsXDoSiwfiUWNmnrvk= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=geCdY4ZG; 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="geCdY4ZG" Received: by smtp.kernel.org (Postfix) with ESMTPSA id D62B1C4CEF7; Fri, 20 Mar 2026 15:32:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1774020760; bh=JQFqRpWHzUfYayHmC0f4Lwr06zQPEuXP1xsc57AEVTo=; h=From:Date:Subject:To:Cc:From; b=geCdY4ZG+bXjGfoz6zeztK1KOm9+oLAnkjmNEdrjWPqdZR9Pu0ueofN7miDHQ4rH/ IP1YfZWtvJTT0cBChVUXZD+idMz7u/W/NtXGgcnwNlO43CEyjRq6DoNqyRImlvrrnY tOqlZ+GyEXfOlkEEVU58SDVLqi+jQni4BQnSE4VQpyL9HIDEjpbTOwj3VZBtOQYCsP RHc4zt+oa6BHKnYRszKNnNYNBGNNEWfyDNkmAGWG0DT/pbFIA677Urg9p2Pu0SZE7V LF3i+ugGUHuJcw2VVHI3P9ZCA11bPQLbWhrIW6Aoq++f9ImfYghviHYlNFx7KNFm9b nkqAGhPNjVoNQ== From: Jeff Layton Date: Fri, 20 Mar 2026 11:32:29 -0400 Subject: [PATCH v4] firmware_loader: add search= module option for multi-path firmware lookup 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: <20260320-fw-path-v4-1-7547e2f0dc64@kernel.org> X-B4-Tracking: v=1; b=H4sIAAAAAAAC/3WO0QqCMBSGX0V23WJnmzq76j2ii03PdBQqm6xCf PemUBDh5fdzvo8zk4DeYSCnbCYeowtu6BPIQ0bqTvctUtckJpzxggkoqX3QUU8d1ayStWA8r3R O0vXo0brnVrpcE3cuTIN/beEI6/ppqG8jAgVaKiWbytgClD3f0Pd4Pw6+JWsk8h2RJ1FpYAWaC tDIP1HsiCKJumSgmTJ1+v5HXJblDSOVWhURAQAA 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=9267; i=jlayton@kernel.org; h=from:subject:message-id; bh=JQFqRpWHzUfYayHmC0f4Lwr06zQPEuXP1xsc57AEVTo=; b=owEBbQKS/ZANAwAKAQAOaEEZVoIVAcsmYgBpvWiSZgna8DxOmjH7zPSrdR2lqZwLj3hYH4fJd hB3zHL/9VWJAjMEAAEKAB0WIQRLwNeyRHGyoYTq9dMADmhBGVaCFQUCab1okgAKCRAADmhBGVaC FVJID/9iWxObOzuN5HRhSsr417YZtNI2gBBujBGGbsUsHtU9a15xlVNlIXKvkcZ7oZFB6dvW1p7 imU9fT34zOWlxjtpyuzyieu2goJ9kHEhIBZEloqJGUbyLDkd7CcpM9ZZIHsogBcs98iFZ4c8qxh lhFfWCFh12UtpwWIdUVpuUKBJ8oqIAghoBioPZ2no+kGXj/cp+2IZZACSRH3UeUdBdKp11K56Et mBp66Ydj2rkMrlknPQmQ3tp+X0IdN4muu3KNsBGCkHra5mJ7CcSI58YrGT2gggRrnWo69xhwaG/ iDbbxHtoWWTJbgX1m4l0c0tzmzd1aSXmnoDYlJIp7gGcJFTZzqe1BGf9BIo6NzjM7SeRDeOYVcq 6H8sh0w8xBPWXTtapClAW05b2XR3amYdz5dJoA8FGp+gMOZGJPUMHNb5yAAFKRdFWrNwFAEVDGd ja4Z/Ho5g1RYLljaxLvrwkdLXqXSS+6kBAApwe6k05cKau/iBtcp/zaE2UNd0kK35rkP9WXX3z0 h9quQMtIbhbFTCM6Nm/4YxKXNKc5d+Jh3HNps2FajfUSmuqLeGvAu2E26wu07yfhUUtof/4khxY Cu3Rlx6MlnSPPi19zG/BW7XcIQsx2bxStD5B1XMekcIaqX4oVHjOHCkZ42cRQRGQPFXhg4cEpN6 34D91jIU+b+zghQ== 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. Add a new firmware_class.search=3D module option that accepts a ':'-separated list of firmware search directories. The firmware lookup order is: 1. firmware_class.path=3D (single legacy path) 2. firmware_class.search=3D (colon-separated paths) 3. Built-in default paths (/lib/firmware/updates/..., /lib/firmware) A backslash can be used as an escape character, allowing a literal ':' ('\:') or literal '\' ('\\') to be embedded in a pathname. Example: firmware_class.search=3D/custom/path1:/custom/path2 Suggested-by: Michal Grzedzicki Signed-off-by: Jeff Layton --- This version adds a new module option called "search=3D" to specify an (escapable) search path. The search=3D path is tried after the original (unescaped) path=3D string, but before the hardcoded search path. --- Changes in v4: - Move search path to new search=3D option that is tried after path=3D - Link to v3: https://lore.kernel.org/r/20260318-fw-path-v3-1-a701a08bc025@= kernel.org Changes in v3: - Allow '\' to escape a literal ':' or '\' in the string - Link to v2: https://lore.kernel.org/r/20260318-fw-path-v2-1-8a106eb91eb4@= kernel.org Changes in v2: - switch to using ':' as path delimiter - Link to v1: https://lore.kernel.org/r/20260318-fw-path-v1-1-7884d9bf618f@= kernel.org --- drivers/base/firmware_loader/main.c | 224 ++++++++++++++++++++++++--------= ---- 1 file changed, 150 insertions(+), 74 deletions(-) diff --git a/drivers/base/firmware_loader/main.c b/drivers/base/firmware_lo= ader/main.c index a11b30dda23be563bd55f25474ceff2153ddd667..0f58d996d3807a1f57dc924adbe= 657360fdfac1e 100644 --- a/drivers/base/firmware_loader/main.c +++ b/drivers/base/firmware_loader/main.c @@ -469,8 +469,8 @@ static int fw_decompress_xz(struct device *dev, struct = fw_priv *fw_priv, =20 /* direct firmware loading support */ static char fw_path_para[256]; +static char fw_search_para[256]; static const char * const fw_path[] =3D { - fw_path_para, "/lib/firmware/updates/" UTS_RELEASE, "/lib/firmware/updates", "/lib/firmware/" UTS_RELEASE, @@ -485,6 +485,82 @@ static const char * const fw_path[] =3D { 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"); =20 +module_param_string(search, fw_search_para, sizeof(fw_search_para), 0644); +MODULE_PARM_DESC(search, "colon-separated list of firmware search paths, t= ried after path=3D (use '\\:' for literal ':', '\\\\' for literal '\\')"); + +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; +} + static int fw_get_filesystem_firmware(struct device *device, struct fw_priv *fw_priv, const char *suffix, @@ -493,10 +569,9 @@ 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 +586,84 @@ 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]; - } =20 - 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; - } + /* Try the single customized path first */ + if (fw_path_para[0]) { + int dirlen =3D strlen(fw_path_para); =20 - fw_priv->size =3D 0; + /* strip trailing newline */ + if (fw_path_para[dirlen - 1] =3D=3D '\n') + dirlen--; =20 - /* - * 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; + rc =3D fw_try_firmware_path(device, fw_priv, suffix, decompress, + fw_path_para, dirlen, + path, &buffer, msize); + if (!rc) + goto done; + } + + /* Try each ':'-separated path in fw_search_para */ + if (fw_search_para[0]) { + const char *start =3D fw_search_para; + const char *p; + char *dir; + + dir =3D __getname(); + if (!dir) { + rc =3D -ENOMEM; + goto done; } - 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; + + while (*start) { + int dirlen =3D 0; + + /* + * Parse the next path component. A backslash + * escapes the following character, allowing + * literal ':' ('\:') and literal '\' ('\\') + * to be embedded in a path. + */ + for (p =3D start; *p && *p !=3D ':'; p++) { + if (p[0] =3D=3D '\\' && (p[1] =3D=3D ':' || p[1] =3D=3D '\\')) + p++; + if (dirlen < PATH_MAX - 1) + dir[dirlen++] =3D *p; } - } 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; + + /* strip trailing newline */ + if (dirlen > 0 && dir[dirlen - 1] =3D=3D '\n') + dirlen--; + + if (dirlen > 0) { + dir[dirlen] =3D '\0'; + rc =3D fw_try_firmware_path(device, fw_priv, + suffix, decompress, + dir, dirlen, + path, &buffer, + msize); + if (!rc) { + __putname(dir); + goto done; + } + } + + if (!*p) + break; + start =3D p + 1; } - fw_state_done(fw_priv); - break; + __putname(dir); } + + /* 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