From nobody Mon Apr 6 16:46:13 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 BADB8319852; Wed, 18 Mar 2026 19:54:16 +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=1773863656; cv=none; b=gIz6khSHLy02eWV5slFv9waG7vUb7xQM4zF4ySyupgnMopI5dDeM+W4HDw4Mhj5QoufPkBOEmTS8dydNFN2XPklMZ/3cnWeSMROJCZ2ct6Bg0pM3i67hzvHHRfxM8kdSkbJBS6acbMcp4LXyn5jXvtXh2tk0haxh/sI7PjnNroE= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773863656; c=relaxed/simple; bh=VFYm78bHcffsCZuS77OCf78K71eXo2oflMbNCecz/I0=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:To:Cc; b=pjz+YFea61RwDVNKqxMUWa0lt3ZBCrI7csbtxPxjzIulO4kL8F0fiVTgYd6Kc3NPm0kaTNwWf5RHx7gREN04JLLA5uj/YnEtxQhllTdK6QzwGnA3oN3XhlHk3+uCJ2vkCeyd8Ce4UCtFjfcTtNcan3wBPm76D62SGEtS0qPLQ90= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=pxK9DWFK; 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="pxK9DWFK" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4E85DC19421; Wed, 18 Mar 2026 19:54:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1773863656; bh=VFYm78bHcffsCZuS77OCf78K71eXo2oflMbNCecz/I0=; h=From:Date:Subject:To:Cc:From; b=pxK9DWFK8J0OWL9TDADWgE/3jXA3Ggr9seih7CmDQkHcNIbaye6za14ULJok3WqtT qoXxmfLKMTTOyC4UIn1YKfU/ipEc362bMkpT7r0oGQB1vGwrNlrxJxyH4tRb2hRKsT nhJ0mUytty5mSFOhqBINk5bk6qtomNMSLNbrl8lM28Km2D6HrO2JOfolKh/FFy6dvG qPY/1zKir9H/GVqTmTfAWn1NFy9B0S0X59yKphFyEFbeImn3Xec1zwgGfPcXk5gb4t p3AWYs+r0omYVgMXTW1OldCSgB7iEbDEMvx8G/fPCvdkc4v8wZFlz5ttYU9WRPRXGs hFgyIK3WDR+kg== From: Jeff Layton Date: Wed, 18 Mar 2026 15:54:02 -0400 Subject: [PATCH v3] 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-v3-1-a701a08bc025@kernel.org> X-B4-Tracking: v=1; b=H4sIAAAAAAAC/3WMyw6CMBBFf4XM2ppOebWu/A/josAUGg0lLakaw r9bSDRx4fLc3HMWCOQtBThlC3iKNlg3JsgPGbSDHntitksMgouK51gz82CTngemuSranItS6RL Se/Jk7HMvXa6JBxtm5197OOK2fhry24jIkNVSFp1qTIXSnG/kR7ofne9hi0TxRxRJlBp5RY1Ca oofcV3XN1qKGovYAAAA 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=8788; i=jlayton@kernel.org; h=from:subject:message-id; bh=VFYm78bHcffsCZuS77OCf78K71eXo2oflMbNCecz/I0=; b=owEBbQKS/ZANAwAKAQAOaEEZVoIVAcsmYgBpuwLhnWdALnCQu+catL1L4cK6IxSI0+ZuxaDq2 uef/7PZ4XCJAjMEAAEKAB0WIQRLwNeyRHGyoYTq9dMADmhBGVaCFQUCabsC4QAKCRAADmhBGVaC FYvoEAC2QwC+Dpd+5BDuq0W4FO20C+b3ky/uH1PWymrM4TVLQiZNMPwxMGxjI0GUDrwZs4+SJdQ /vawV6AV/Iks+8PSS8Yil8b1Uxotsx74+3D3fUsHvPB9hN3TdDL9UAOimnFDKj4qeFnRy8/xcp5 ZLZzCeXOFrWjRckJFravWyH1lXeOf5Wq7o1+VA2/wXxhCj+vGNl5++O0qoQEs8fAsZA4JRSSvR9 NfcI+e4Sz3j02th8TJOym1uUkE7gApP+ySUFTMD0W3RBRp9v6OwEWDJuv1ex+pg2eJRQmQEiS4m pWf4Cj6R4sR5nlJ2i+JIJ8zWsAuoTl5Es7v/p4NXTLa4e52h+4+q74ffWlMZQxbXtRyMyBRbfIW P9IjieW2IA2+ArOQibzLK69NXk9IeLUxyKLDACngibuHiAQ6ezvsmX1oSiD4HDG1x/xR9FrIwpm hVdDQjiN3NjmyQolOy6oInTmsVBRFQ819Gwwr4pKB3oupvWbeiQNdrHWtA2cD9U3ARise7UGch3 9mbqU2Q5JCiC6DPXuuT1nqd9y5IO1hvBYfeYI9VwXBjdX8kYJHxV4gc2L3z17YdQ80a9RnTe45B 97SDoQQFM4tC+rvzcDjFNxEmssrQzftk6RxDZXRSZWPEyHUMk5htLRi6QSkPZLDgmfjGq8VUile xa2L3n9fSvzGyUA== 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 A backslash can be used as an escape character, allowing a literal ':' ("\:") or literal '\' ("\\") to be embedded in a pathname. Suggested-by: Michal Grzedzicki Signed-off-by: Jeff Layton --- Michal privately pointed out that this didn't have provision to handle an embedded ':' in the filename. This version adds support for escaping ':' and '\' in the filename via backslash characters. --- 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 | 209 +++++++++++++++++++++++---------= ---- 1 file changed, 133 insertions(+), 76 deletions(-) diff --git a/drivers/base/firmware_loader/main.c b/drivers/base/firmware_lo= ader/main.c index a11b30dda23be563bd55f25474ceff2153ddd667..7f35100ae1a7575deed57bdf9b5= 823f87ce5d115 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 ':' (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; +} =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 +582,69 @@ 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 each ':'-separated path in fw_path_para first */ + if (fw_path_para[0]) { + const char *start =3D fw_path_para; + const char *p; + char *dir; =20 - fw_priv->size =3D 0; + dir =3D __getname(); + if (!dir) { + rc =3D -ENOMEM; + goto done; + } =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); + 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; } - 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; + + /* 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; + } } - } 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 (!*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