From 007ec26cdc9fefacbed85b592afc69413194499c Mon Sep 17 00:00:00 2001 From: David Howells Date: Thu, 1 Nov 2018 23:34:29 +0000 Subject: vfs: Implement logging through fs_context Implement the ability for filesystems to log error, warning and informational messages through the fs_context. These can be extracted by userspace by reading from an fd created by fsopen(). Error messages are prefixed with "e ", warnings with "w " and informational messages with "i ". Inside the kernel, formatted messages are malloc'd but unformatted messages are not copied if they're either in the core .rodata section or in the .rodata section of the filesystem module pinned by fs_context::fs_type. The messages are only good till the fs_type is released. Note that the logging object is shared between duplicated fs_context structures. This is so that such as NFS which do a mount within a mount can get at least some of the errors from the inner mount. Five logging functions are provided for this: (1) void logfc(struct fs_context *fc, const char *fmt, ...); This logs a message into the context. If the buffer is full, the earliest message is discarded. (2) void errorf(fc, fmt, ...); This wraps logfc() to log an error. (3) void invalf(fc, fmt, ...); This wraps errorf() and returns -EINVAL for convenience. (4) void warnf(fc, fmt, ...); This wraps logfc() to log a warning. (5) void infof(fc, fmt, ...); This wraps logfc() to log an informational message. Signed-off-by: David Howells Signed-off-by: Al Viro --- include/linux/module.h | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'include/linux/module.h') diff --git a/include/linux/module.h b/include/linux/module.h index 5bf5dcd91009..7dc4dc79b634 100644 --- a/include/linux/module.h +++ b/include/linux/module.h @@ -709,6 +709,12 @@ static inline bool is_module_text_address(unsigned long addr) return false; } +static inline bool within_module_core(unsigned long addr, + const struct module *mod) +{ + return false; +} + /* Get/put a kernel symbol (calls should be symmetric) */ #define symbol_get(x) ({ extern typeof(x) x __attribute__((weak)); &(x); }) #define symbol_put(x) do { } while (0) -- cgit v1.2.3 From 8db5da0b8618df79eceea99672e205d4a2a6309e Mon Sep 17 00:00:00 2001 From: Mimi Zohar Date: Sun, 27 Jan 2019 19:03:45 -0500 Subject: x86/ima: require signed kernel modules Have the IMA architecture specific policy require signed kernel modules on systems with secure boot mode enabled; and coordinate the different signature verification methods, so only one signature is required. Requiring appended kernel module signatures may be configured, enabled on the boot command line, or with this patch enabled in secure boot mode. This patch defines set_module_sig_enforced(). To coordinate between appended kernel module signatures and IMA signatures, only define an IMA MODULE_CHECK policy rule if CONFIG_MODULE_SIG is not enabled. A custom IMA policy may still define and require an IMA signature. Signed-off-by: Mimi Zohar Reviewed-by: Luis Chamberlain Acked-by: Jessica Yu --- include/linux/module.h | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'include/linux/module.h') diff --git a/include/linux/module.h b/include/linux/module.h index 5bf5dcd91009..73ee2b10e816 100644 --- a/include/linux/module.h +++ b/include/linux/module.h @@ -676,6 +676,7 @@ static inline bool is_livepatch_module(struct module *mod) #endif /* CONFIG_LIVEPATCH */ bool is_module_sig_enforced(void); +void set_module_sig_enforced(void); #else /* !CONFIG_MODULES... */ @@ -796,6 +797,10 @@ static inline bool is_module_sig_enforced(void) return false; } +static inline void set_module_sig_enforced(void) +{ +} + /* Dereference module function descriptor */ static inline void *dereference_module_function_descriptor(struct module *mod, void *ptr) -- cgit v1.2.3 From 1c7651f43777cdd59c1aaa82c87324d3e7438c7b Mon Sep 17 00:00:00 2001 From: Eugene Loh Date: Mon, 25 Feb 2019 11:59:58 -0800 Subject: kallsyms: store type information in its own array When a module is loaded, its symbols' Elf_Sym information is stored in a symtab. Further, type information is also captured. Since Elf_Sym has no type field, historically the st_info field has been hijacked for storing type: st_info was overwritten. commit 5439c985c5a83a8419f762115afdf560ab72a452 ("module: Overwrite st_size instead of st_info") changes that practice, as its one-liner indicates. Unfortunately, this change overwrites symbol size, information that a tool like DTrace expects to find. Allocate a typetab array to store type information so that no Elf_Sym field needs to be overwritten. Fixes: 5439c985c5a8 ("module: Overwrite st_size instead of st_info") Signed-off-by: Eugene Loh Reviewed-by: Nick Alcock [jeyu: renamed typeoff -> typeoffs ] Signed-off-by: Jessica Yu --- include/linux/module.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/linux/module.h') diff --git a/include/linux/module.h b/include/linux/module.h index 5bf5dcd91009..3abe8176df98 100644 --- a/include/linux/module.h +++ b/include/linux/module.h @@ -331,6 +331,7 @@ struct mod_kallsyms { Elf_Sym *symtab; unsigned int num_symtab; char *strtab; + char *typetab; }; #ifdef CONFIG_LIVEPATCH -- cgit v1.2.3 From dadec066d8fa7da227f623f632ea114690fecaf8 Mon Sep 17 00:00:00 2001 From: Tri Vo Date: Mon, 15 Apr 2019 11:18:33 -0700 Subject: module: add stubs for within_module functions Provide stubs for within_module_core(), within_module_init(), and within_module() to prevent build errors when !CONFIG_MODULES. Suggested-by: Matthew Wilcox Reported-by: Randy Dunlap Reported-by: kbuild test robot Link: https://marc.info/?l=linux-mm&m=155384681109231&w=2 Signed-off-by: Tri Vo Signed-off-by: Jessica Yu --- include/linux/module.h | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) (limited to 'include/linux/module.h') diff --git a/include/linux/module.h b/include/linux/module.h index 3abe8176df98..7e63c340a8bf 100644 --- a/include/linux/module.h +++ b/include/linux/module.h @@ -710,6 +710,23 @@ static inline bool is_module_text_address(unsigned long addr) return false; } +static inline bool within_module_core(unsigned long addr, + const struct module *mod) +{ + return false; +} + +static inline bool within_module_init(unsigned long addr, + const struct module *mod) +{ + return false; +} + +static inline bool within_module(unsigned long addr, const struct module *mod) +{ + return false; +} + /* Get/put a kernel symbol (calls should be symmetric) */ #define symbol_get(x) ({ extern typeof(x) x __attribute__((weak)); &(x); }) #define symbol_put(x) do { } while (0) -- cgit v1.2.3 From 898490c010b5d2e499e03b7e815fc214209ac583 Mon Sep 17 00:00:00 2001 From: Alexey Gladkov Date: Mon, 29 Apr 2019 18:11:14 +0200 Subject: moduleparam: Save information about built-in modules in separate file Problem: When a kernel module is compiled as a separate module, some important information about the kernel module is available via .modinfo section of the module. In contrast, when the kernel module is compiled into the kernel, that information is not available. Information about built-in modules is necessary in the following cases: 1. When it is necessary to find out what additional parameters can be passed to the kernel at boot time. 2. When you need to know which module names and their aliases are in the kernel. This is very useful for creating an initrd image. Proposal: The proposed patch does not remove .modinfo section with module information from the vmlinux at the build time and saves it into a separate file after kernel linking. So, the kernel does not increase in size and no additional information remains in it. Information is stored in the same format as in the separate modules (null-terminated string array). Because the .modinfo section is already exported with a separate modules, we are not creating a new API. It can be easily read in the userspace: $ tr '\0' '\n' < modules.builtin.modinfo ext4.softdep=pre: crc32c ext4.license=GPL ext4.description=Fourth Extended Filesystem ext4.author=Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others ext4.alias=fs-ext4 ext4.alias=ext3 ext4.alias=fs-ext3 ext4.alias=ext2 ext4.alias=fs-ext2 md_mod.alias=block-major-9-* md_mod.alias=md md_mod.description=MD RAID framework md_mod.license=GPL md_mod.parmtype=create_on_open:bool md_mod.parmtype=start_dirty_degraded:int ... Co-Developed-by: Gleb Fotengauer-Malinovskiy Signed-off-by: Gleb Fotengauer-Malinovskiy Signed-off-by: Alexey Gladkov Acked-by: Jessica Yu Signed-off-by: Masahiro Yamada --- include/linux/module.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/linux/module.h') diff --git a/include/linux/module.h b/include/linux/module.h index 5bf5dcd91009..5f7007430d35 100644 --- a/include/linux/module.h +++ b/include/linux/module.h @@ -253,6 +253,7 @@ extern typeof(name) __mod_##type##__##name##_device_table \ #define MODULE_VERSION(_version) MODULE_INFO(version, _version) #else #define MODULE_VERSION(_version) \ + MODULE_INFO(version, _version); \ static struct module_version_attribute ___modver_attr = { \ .mattr = { \ .attr = { \ -- cgit v1.2.3