diff options
34 files changed, 613 insertions, 68 deletions
diff --git a/.gitignore b/.gitignore index ce2c6348d372..70580bdd352c 100644 --- a/.gitignore +++ b/.gitignore @@ -32,6 +32,7 @@ *.lzo *.mod *.mod.c +*.ns_deps *.o *.o.* *.patch diff --git a/Documentation/kbuild/modules.rst b/Documentation/kbuild/modules.rst index 24e763482650..d2ae799237fd 100644 --- a/Documentation/kbuild/modules.rst +++ b/Documentation/kbuild/modules.rst @@ -470,9 +470,12 @@ build. The syntax of the Module.symvers file is:: - <CRC> <Symbol> <module> + <CRC> <Symbol> <Namespace> <Module> <Export Type> - 0x2d036834 scsi_remove_host drivers/scsi/scsi_mod + 0xe1cc2a05 usb_stor_suspend USB_STORAGE drivers/usb/storage/usb-storage EXPORT_SYMBOL_GPL + + The fields are separated by tabs and values may be empty (e.g. + if no namespace is defined for an exported symbol). For a kernel build without CONFIG_MODVERSIONS enabled, the CRC would read 0x00000000. diff --git a/Documentation/kbuild/namespaces.rst b/Documentation/kbuild/namespaces.rst new file mode 100644 index 000000000000..982ed7b568ac --- /dev/null +++ b/Documentation/kbuild/namespaces.rst @@ -0,0 +1,154 @@ +================= +Symbol Namespaces +================= + +The following document describes how to use Symbol Namespaces to structure the +export surface of in-kernel symbols exported through the family of +EXPORT_SYMBOL() macros. + +.. Table of Contents + + === 1 Introduction + === 2 How to define Symbol Namespaces + --- 2.1 Using the EXPORT_SYMBOL macros + --- 2.2 Using the DEFAULT_SYMBOL_NAMESPACE define + === 3 How to use Symbols exported in Namespaces + === 4 Loading Modules that use namespaced Symbols + === 5 Automatically creating MODULE_IMPORT_NS statements + +1. Introduction +=============== + +Symbol Namespaces have been introduced as a means to structure the export +surface of the in-kernel API. It allows subsystem maintainers to partition +their exported symbols into separate namespaces. That is useful for +documentation purposes (think of the SUBSYSTEM_DEBUG namespace) as well as for +limiting the availability of a set of symbols for use in other parts of the +kernel. As of today, modules that make use of symbols exported into namespaces, +are required to import the namespace. Otherwise the kernel will, depending on +its configuration, reject loading the module or warn about a missing import. + +2. How to define Symbol Namespaces +================================== + +Symbols can be exported into namespace using different methods. All of them are +changing the way EXPORT_SYMBOL and friends are instrumented to create ksymtab +entries. + +2.1 Using the EXPORT_SYMBOL macros +================================== + +In addition to the macros EXPORT_SYMBOL() and EXPORT_SYMBOL_GPL(), that allow +exporting of kernel symbols to the kernel symbol table, variants of these are +available to export symbols into a certain namespace: EXPORT_SYMBOL_NS() and +EXPORT_SYMBOL_NS_GPL(). They take one additional argument: the namespace. +Please note that due to macro expansion that argument needs to be a +preprocessor symbol. E.g. to export the symbol `usb_stor_suspend` into the +namespace `USB_STORAGE`, use:: + + EXPORT_SYMBOL_NS(usb_stor_suspend, USB_STORAGE); + +The corresponding ksymtab entry struct `kernel_symbol` will have the member +`namespace` set accordingly. A symbol that is exported without a namespace will +refer to `NULL`. There is no default namespace if none is defined. `modpost` +and kernel/module.c make use the namespace at build time or module load time, +respectively. + +2.2 Using the DEFAULT_SYMBOL_NAMESPACE define +============================================= + +Defining namespaces for all symbols of a subsystem can be very verbose and may +become hard to maintain. Therefore a default define (DEFAULT_SYMBOL_NAMESPACE) +is been provided, that, if set, will become the default for all EXPORT_SYMBOL() +and EXPORT_SYMBOL_GPL() macro expansions that do not specify a namespace. + +There are multiple ways of specifying this define and it depends on the +subsystem and the maintainer's preference, which one to use. The first option +is to define the default namespace in the `Makefile` of the subsystem. E.g. to +export all symbols defined in usb-common into the namespace USB_COMMON, add a +line like this to drivers/usb/common/Makefile:: + + ccflags-y += -DDEFAULT_SYMBOL_NAMESPACE=USB_COMMON + +That will affect all EXPORT_SYMBOL() and EXPORT_SYMBOL_GPL() statements. A +symbol exported with EXPORT_SYMBOL_NS() while this definition is present, will +still be exported into the namespace that is passed as the namespace argument +as this argument has preference over a default symbol namespace. + +A second option to define the default namespace is directly in the compilation +unit as preprocessor statement. The above example would then read:: + + #undef DEFAULT_SYMBOL_NAMESPACE + #define DEFAULT_SYMBOL_NAMESPACE USB_COMMON + +within the corresponding compilation unit before any EXPORT_SYMBOL macro is +used. + +3. How to use Symbols exported in Namespaces +============================================ + +In order to use symbols that are exported into namespaces, kernel modules need +to explicitly import these namespaces. Otherwise the kernel might reject to +load the module. The module code is required to use the macro MODULE_IMPORT_NS +for the namespaces it uses symbols from. E.g. a module using the +usb_stor_suspend symbol from above, needs to import the namespace USB_STORAGE +using a statement like:: + + MODULE_IMPORT_NS(USB_STORAGE); + +This will create a `modinfo` tag in the module for each imported namespace. +This has the side effect, that the imported namespaces of a module can be +inspected with modinfo:: + + $ modinfo drivers/usb/storage/ums-karma.ko + [...] + import_ns: USB_STORAGE + [...] + + +It is advisable to add the MODULE_IMPORT_NS() statement close to other module +metadata definitions like MODULE_AUTHOR() or MODULE_LICENSE(). Refer to section +5. for a way to create missing import statements automatically. + +4. Loading Modules that use namespaced Symbols +============================================== + +At module loading time (e.g. `insmod`), the kernel will check each symbol +referenced from the module for its availability and whether the namespace it +might be exported to has been imported by the module. The default behaviour of +the kernel is to reject loading modules that don't specify sufficient imports. +An error will be logged and loading will be failed with EINVAL. In order to +allow loading of modules that don't satisfy this precondition, a configuration +option is available: Setting MODULE_ALLOW_MISSING_NAMESPACE_IMPORTS=y will +enable loading regardless, but will emit a warning. + +5. Automatically creating MODULE_IMPORT_NS statements +===================================================== + +Missing namespaces imports can easily be detected at build time. In fact, +modpost will emit a warning if a module uses a symbol from a namespace +without importing it. +MODULE_IMPORT_NS() statements will usually be added at a definite location +(along with other module meta data). To make the life of module authors (and +subsystem maintainers) easier, a script and make target is available to fixup +missing imports. Fixing missing imports can be done with:: + + $ make nsdeps + +A typical scenario for module authors would be:: + + - write code that depends on a symbol from a not imported namespace + - `make` + - notice the warning of modpost telling about a missing import + - run `make nsdeps` to add the import to the correct code location + +For subsystem maintainers introducing a namespace, the steps are very similar. +Again, `make nsdeps` will eventually add the missing namespace imports for +in-tree modules:: + + - move or add symbols to a namespace (e.g. with EXPORT_SYMBOL_NS()) + - `make` (preferably with an allmodconfig to cover all in-kernel + modules) + - notice the warning of modpost telling about a missing import + - run `make nsdeps` to add the import to the correct code location + diff --git a/Documentation/kernel-hacking/hacking.rst b/Documentation/kernel-hacking/hacking.rst index 5891a701a159..a3ddb213a5e1 100644 --- a/Documentation/kernel-hacking/hacking.rst +++ b/Documentation/kernel-hacking/hacking.rst @@ -594,6 +594,24 @@ internal implementation issue, and not really an interface. Some maintainers and developers may however require EXPORT_SYMBOL_GPL() when adding any new APIs or functionality. +:c:func:`EXPORT_SYMBOL_NS()` +---------------------------- + +Defined in ``include/linux/export.h`` + +This is the variant of `EXPORT_SYMBOL()` that allows specifying a symbol +namespace. Symbol Namespaces are documented in +``Documentation/kbuild/namespaces.rst``. + +:c:func:`EXPORT_SYMBOL_NS_GPL()` +-------------------------------- + +Defined in ``include/linux/export.h`` + +This is the variant of `EXPORT_SYMBOL_GPL()` that allows specifying a symbol +namespace. Symbol Namespaces are documented in +``Documentation/kbuild/namespaces.rst``. + Routines and Conventions ======================== diff --git a/MAINTAINERS b/MAINTAINERS index 00ace1a989f9..64f63e321fa4 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -11523,6 +11523,11 @@ S: Maintained T: git git://git.kernel.org/pub/scm/linux/kernel/git/wtarreau/nolibc.git F: tools/include/nolibc/ +NSDEPS +M: Matthias Maennich <maennich@google.com> +S: Maintained +F: scripts/nsdeps + NTB AMD DRIVER M: Shyam Sundar S K <Shyam-sundar.S-k@amd.com> L: linux-ntb@googlegroups.com @@ -1498,6 +1498,9 @@ help: @echo ' headerdep - Detect inclusion cycles in headers' @echo ' coccicheck - Check with Coccinelle' @echo '' + @echo 'Tools:' + @echo ' nsdeps - Generate missing symbol namespace dependencies' + @echo '' @echo 'Kernel selftest:' @echo ' kselftest - Build and run kernel selftest (run as root)' @echo ' Build, install, and boot kernel before' @@ -1679,7 +1682,7 @@ clean: $(clean-dirs) -o -name '*.ko.*' \ -o -name '*.dtb' -o -name '*.dtb.S' -o -name '*.dt.yaml' \ -o -name '*.dwo' -o -name '*.lst' \ - -o -name '*.su' -o -name '*.mod' \ + -o -name '*.su' -o -name '*.mod' -o -name '*.ns_deps' \ -o -name '.*.d' -o -name '.*.tmp' -o -name '*.mod.c' \ -o -name '*.lex.c' -o -name '*.tab.[ch]' \ -o -name '*.asn1.[ch]' \ @@ -1697,6 +1700,15 @@ quiet_cmd_tags = GEN $@ tags TAGS cscope gtags: FORCE $(call cmd,tags) +# Script to generate missing namespace dependencies +# --------------------------------------------------------------------------- + +PHONY += nsdeps + +nsdeps: modules + $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost nsdeps + $(Q)$(CONFIG_SHELL) $(srctree)/scripts/$@ + # Scripts to check various things for consistency # --------------------------------------------------------------------------- diff --git a/arch/m68k/include/asm/export.h b/arch/m68k/include/asm/export.h index 0af20f48bd07..b53008b67ce1 100644 --- a/arch/m68k/include/asm/export.h +++ b/arch/m68k/include/asm/export.h @@ -1,3 +1,2 @@ -#define KSYM_ALIGN 2 #define KCRC_ALIGN 2 #include <asm-generic/export.h> diff --git a/drivers/usb/storage/Makefile b/drivers/usb/storage/Makefile index a67ddcbb4e24..46635fa4a340 100644 --- a/drivers/usb/storage/Makefile +++ b/drivers/usb/storage/Makefile @@ -8,6 +8,8 @@ ccflags-y := -I $(srctree)/drivers/scsi +ccflags-y += -DDEFAULT_SYMBOL_NAMESPACE=USB_STORAGE + obj-$(CONFIG_USB_UAS) += uas.o obj-$(CONFIG_USB_STORAGE) += usb-storage.o diff --git a/drivers/usb/storage/alauda.c b/drivers/usb/storage/alauda.c index 6b8edf6178df..ddab2cd3d2e7 100644 --- a/drivers/usb/storage/alauda.c +++ b/drivers/usb/storage/alauda.c @@ -36,6 +36,7 @@ MODULE_DESCRIPTION("Driver for Alauda-based card readers"); MODULE_AUTHOR("Daniel Drake <dsd@gentoo.org>"); MODULE_LICENSE("GPL"); +MODULE_IMPORT_NS(USB_STORAGE); /* * Status bytes diff --git a/drivers/usb/storage/cypress_atacb.c b/drivers/usb/storage/cypress_atacb.c index 4825902377eb..a6f3267bbef6 100644 --- a/drivers/usb/storage/cypress_atacb.c +++ b/drivers/usb/storage/cypress_atacb.c @@ -22,6 +22,7 @@ MODULE_DESCRIPTION("SAT support for Cypress USB/ATA bridges with ATACB"); MODULE_AUTHOR("Matthieu Castet <castet.matthieu@free.fr>"); MODULE_LICENSE("GPL"); +MODULE_IMPORT_NS(USB_STORAGE); /* * The table of devices diff --git a/drivers/usb/storage/datafab.c b/drivers/usb/storage/datafab.c index 09353be199be..588818483f4b 100644 --- a/drivers/usb/storage/datafab.c +++ b/drivers/usb/storage/datafab.c @@ -54,6 +54,7 @@ MODULE_DESCRIPTION("Driver for Datafab USB Compact Flash reader"); MODULE_AUTHOR("Jimmie Mayfield <mayfield+datafab@sackheads.org>"); MODULE_LICENSE("GPL"); +MODULE_IMPORT_NS(USB_STORAGE); struct datafab_info { unsigned long sectors; /* total sector count */ diff --git a/drivers/usb/storage/ene_ub6250.c b/drivers/usb/storage/ene_ub6250.c index c26129d5b943..8b1b73065421 100644 --- a/drivers/usb/storage/ene_ub6250.c +++ b/drivers/usb/storage/ene_ub6250.c @@ -26,6 +26,7 @@ MODULE_DESCRIPTION("Driver for ENE UB6250 reader"); MODULE_LICENSE("GPL"); +MODULE_IMPORT_NS(USB_STORAGE); MODULE_FIRMWARE(SD_INIT1_FIRMWARE); MODULE_FIRMWARE(SD_INIT2_FIRMWARE); MODULE_FIRMWARE(SD_RW_FIRMWARE); diff --git a/drivers/usb/storage/freecom.c b/drivers/usb/storage/freecom.c index 4f542df37a44..34e7eaff1174 100644 --- a/drivers/usb/storage/freecom.c +++ b/drivers/usb/storage/freecom.c @@ -29,6 +29,7 @@ MODULE_DESCRIPTION("Driver for Freecom USB/IDE adaptor"); MODULE_AUTHOR("David Brown <usb-storage@davidb.org>"); MODULE_LICENSE("GPL"); +MODULE_IMPORT_NS(USB_STORAGE); #ifdef CONFIG_USB_STORAGE_DEBUG static void pdump(struct us_data *us, void *ibuffer, int length); diff --git a/drivers/usb/storage/isd200.c b/drivers/usb/storage/isd200.c index 28e1128d53a4..89f5e33a6e6d 100644 --- a/drivers/usb/storage/isd200.c +++ b/drivers/usb/storage/isd200.c @@ -53,6 +53,7 @@ MODULE_DESCRIPTION("Driver for In-System Design, Inc. ISD200 ASIC"); MODULE_AUTHOR("Björn Stenberg <bjorn@haxx.se>"); MODULE_LICENSE("GPL"); +MODULE_IMPORT_NS(USB_STORAGE); static int isd200_Initialization(struct us_data *us); diff --git a/drivers/usb/storage/jumpshot.c b/drivers/usb/storage/jumpshot.c index 917f170c4124..229bf0c1afc9 100644 --- a/drivers/usb/storage/jumpshot.c +++ b/drivers/usb/storage/jumpshot.c @@ -51,6 +51,7 @@ MODULE_DESCRIPTION("Driver for Lexar \"Jumpshot\" Compact Flash reader"); MODULE_AUTHOR("Jimmie Mayfield <mayfield+usb@sackheads.org>"); MODULE_LICENSE("GPL"); +MODULE_IMPORT_NS(USB_STORAGE); /* * The table of devices diff --git a/drivers/usb/storage/karma.c b/drivers/usb/storage/karma.c index 395cf8fb5870..05cec81dcd3f 100644 --- a/drivers/usb/storage/karma.c +++ b/drivers/usb/storage/karma.c @@ -23,6 +23,7 @@ MODULE_DESCRIPTION("Driver for Rio Karma"); MODULE_AUTHOR("Bob Copeland <me@bobcopeland.com>, Keith Bennett <keith@mcs.st-and.ac.uk>"); MODULE_LICENSE("GPL"); +MODULE_IMPORT_NS(USB_STORAGE); #define RIO_PREFIX "RIOP\x00" #define RIO_PREFIX_LEN 5 diff --git a/drivers/usb/storage/onetouch.c b/drivers/usb/storage/onetouch.c index 39a5009a41a6..a989fe930e21 100644 --- a/drivers/usb/storage/onetouch.c +++ b/drivers/usb/storage/onetouch.c @@ -25,6 +25,7 @@ MODULE_DESCRIPTION("Maxtor USB OneTouch hard drive button driver"); MODULE_AUTHOR("Nick Sillik <n.sillik@temple.edu>"); MODULE_LICENSE("GPL"); +MODULE_IMPORT_NS(USB_STORAGE); #define ONETOUCH_PKT_LEN 0x02 #define ONETOUCH_BUTTON KEY_PROG1 diff --git a/drivers/usb/storage/realtek_cr.c b/drivers/usb/storage/realtek_cr.c index 1d9ce9cbc831..3789698d9d3c 100644 --- a/drivers/usb/storage/realtek_cr.c +++ b/drivers/usb/storage/realtek_cr.c @@ -35,6 +35,7 @@ MODULE_DESCRIPTION("Driver for Realtek USB Card Reader"); MODULE_AUTHOR("wwang <wei_wang@realsil.com.cn>"); MODULE_LICENSE("GPL"); +MODULE_IMPORT_NS(USB_STORAGE); static int auto_delink_en = 1; module_param(auto_delink_en, int, S_IRUGO | S_IWUSR); diff --git a/drivers/usb/storage/sddr09.c b/drivers/usb/storage/sddr09.c index bc9da736bdfc..51bcd4a43690 100644 --- a/drivers/usb/storage/sddr09.c +++ b/drivers/usb/storage/sddr09.c @@ -47,6 +47,7 @@ MODULE_DESCRIPTION("Driver for SanDisk SDDR-09 SmartMedia reader"); MODULE_AUTHOR("Andries Brouwer <aeb@cwi.nl>, Robert Baruch <autophile@starband.net>"); MODULE_LICENSE("GPL"); +MODULE_IMPORT_NS(USB_STORAGE); static int usb_stor_sddr09_dpcm_init(struct us_data *us); static int sddr09_transport(struct scsi_cmnd *srb, struct us_data *us); diff --git a/drivers/usb/storage/sddr55.c b/drivers/usb/storage/sddr55.c index b8527c55335b..ba955d65eb0e 100644 --- a/drivers/usb/storage/sddr55.c +++ b/drivers/usb/storage/sddr55.c @@ -29,6 +29,7 @@ MODULE_DESCRIPTION("Driver for SanDisk SDDR-55 SmartMedia reader"); MODULE_AUTHOR("Simon Munton"); MODULE_LICENSE("GPL"); +MODULE_IMPORT_NS(USB_STORAGE); /* * The table of devices diff --git a/drivers/usb/storage/shuttle_usbat.c b/drivers/usb/storage/shuttle_usbat.c index 854498e1012c..54aa1392c9ca 100644 --- a/drivers/usb/storage/shuttle_usbat.c +++ b/drivers/usb/storage/shuttle_usbat.c @@ -48,6 +48,7 @@ MODULE_DESCRIPTION("Driver for SCM Microsystems (a.k.a. Shuttle) USB-ATAPI cable"); MODULE_AUTHOR("Daniel Drake <dsd@gentoo.org>, Robert Baruch <autophile@starband.net>"); MODULE_LICENSE("GPL"); +MODULE_IMPORT_NS(USB_STORAGE); /* Supported device types */ #define USBAT_DEV_HP8200 0x01 diff --git a/drivers/usb/storage/uas.c b/drivers/usb/storage/uas.c index 047c5922618f..bf80d6f81f58 100644 --- a/drivers/usb/storage/uas.c +++ b/drivers/usb/storage/uas.c @@ -1219,5 +1219,6 @@ static struct usb_driver uas_driver = { module_usb_driver(uas_driver); MODULE_LICENSE("GPL"); +MODULE_IMPORT_NS(USB_STORAGE); MODULE_AUTHOR( "Hans de Goede <hdegoede@redhat.com>, Matthew Wilcox and Sarah Sharp"); diff --git a/include/asm-generic/export.h b/include/asm-generic/export.h index 294d6ae785d4..fa577978fbbd 100644 --- a/include/asm-generic/export.h +++ b/include/asm-generic/export.h @@ -4,26 +4,24 @@ #ifndef KSYM_FUNC #define KSYM_FUNC(x) x #endif -#ifdef CONFIG_64BIT -#ifndef KSYM_ALIGN +#ifdef CONFIG_HAVE_ARCH_PREL32_RELOCATIONS +#define KSYM_ALIGN 4 +#elif defined(CONFIG_64BIT) #define KSYM_ALIGN 8 -#endif #else -#ifndef KSYM_ALIGN #define KSYM_ALIGN 4 #endif -#endif #ifndef KCRC_ALIGN #define KCRC_ALIGN 4 #endif .macro __put, val, name #ifdef CONFIG_HAVE_ARCH_PREL32_RELOCATIONS - .long \val - ., \name - . + .long \val - ., \name - ., 0 #elif defined(CONFIG_64BIT) - .quad \val, \name + .quad \val, \name, 0 #else - .long \val, \name + .long \val, \name, 0 #endif .endm @@ -57,7 +55,6 @@ __kcrctab_\name: #endif #endif .endm -#undef __put #if defined(CONFIG_TRIM_UNUSED_KSYMS) diff --git a/include/linux/export.h b/include/linux/export.h index 7d8c112a8b61..95f55b7f83a0 100644 --- a/include/linux/export.h +++ b/include/linux/export.h @@ -18,6 +18,8 @@ extern struct module __this_module; #define THIS_MODULE ((struct module *)0) #endif +#define NS_SEPARATOR "." + #ifdef CONFIG_MODVERSIONS /* Mark the CRC weak since genksyms apparently decides not to * generate a checksums for some symbols */ @@ -26,13 +28,13 @@ extern struct module __this_module; asm(" .section \"___kcrctab" sec "+" #sym "\", \"a\" \n" \ " .weak __crc_" #sym " \n" \ " .long __crc_" #sym " - . \n" \ - " .previous \n"); + " .previous \n") #else #define __CRC_SYMBOL(sym, sec) \ asm(" .section \"___kcrctab" sec "+" #sym "\", \"a\" \n" \ " .weak __crc_" #sym " \n" \ " .long __crc_" #sym " \n" \ - " .previous \n"); + " .previous \n") #endif #else #define __CRC_SYMBOL(sym, sec) @@ -46,44 +48,77 @@ extern struct module __this_module; * absolute relocations that require runtime processing on relocatable * kernels. */ +#define __KSYMTAB_ENTRY_NS(sym, sec, ns) \ + __ADDRESSABLE(sym) \ + asm(" .section \"___ksymtab" sec "+" #sym "\", \"a\" \n" \ + " .balign 4 \n" \ + "__ksymtab_" #sym NS_SEPARATOR #ns ": \n" \ + " .long " #sym "- . \n" \ + " .long __kstrtab_" #sym "- . \n" \ + " .long __kstrtab_ns_" #sym "- . \n" \ + " .previous \n") + #define __KSYMTAB_ENTRY(sym, sec) \ __ADDRESSABLE(sym) \ asm(" .section \"___ksymtab" sec "+" #sym "\", \"a\" \n" \ - " .balign 8 \n" \ + " .balign 4 \n" \ "__ksymtab_" #sym ": \n" \ " .long " #sym "- . \n" \ " .long __kstrtab_" #sym "- . \n" \ + " .long 0 \n" \ " .previous \n") struct kernel_symbol { int value_offset; int name_offset; + int namespace_offset; }; #else +#define __KSYMTAB_ENTRY_NS(sym, sec, ns) \ + static const struct kernel_symbol __ksymtab_##sym##__##ns \ + asm("__ksymtab_" #sym NS_SEPARATOR #ns) \ + __attribute__((section("___ksymtab" sec "+" #sym), used)) \ + __aligned(sizeof(void *)) \ + = { (unsigned long)&sym, __kstrtab_##sym, __kstrtab_ns_##sym } + #define __KSYMTAB_ENTRY(sym, sec) \ static const struct kernel_symbol __ksymtab_##sym \ + asm("__ksymtab_" #sym) \ __attribute__((section("___ksymtab" sec "+" #sym), used)) \ - = { (unsigned long)&sym, __kstrtab_##sym } + __aligned(sizeof(void *)) \ + = { (unsigned long)&sym, __kstrtab_##sym, NULL } struct kernel_symbol { unsigned long value; const char *name; + const char *namespace; }; #endif #ifdef __GENKSYMS__ -#define ___EXPORT_SYMBOL(sym, sec) __GENKSYMS_EXPORT_SYMBOL(sym) +#define ___EXPORT_SYMBOL(sym,sec) __GENKSYMS_EXPORT_SYMBOL(sym) +#define ___EXPORT_SYMBOL_NS(sym,sec,ns) __GENKSYMS_EXPORT_SYMBOL(sym) #else -/* For every exported symbol, place a struct in the __ksymtab section */ -#define ___EXPORT_SYMBOL(sym, sec) \ +#define ___export_symbol_common(sym, sec) \ extern typeof(sym) sym; \ - __CRC_SYMBOL(sym, sec) \ + __CRC_SYMBOL(sym, sec); \ static const char __kstrtab_##sym[] \ __attribute__((section("__ksymtab_strings"), used, aligned(1))) \ - = #sym; \ + = #sym \ + +/* For every exported symbol, place a struct in the __ksymtab section */ +#define ___EXPORT_SYMBOL_NS(sym, sec, ns) \ + ___export_symbol_common(sym, sec); \ + static const char __kstrtab_ns_##sym[] \ + __attribute__((section("__ksymtab_strings"), used, aligned(1))) \ + = #ns; \ + __KSYMTAB_ENTRY_NS(sym, sec, ns) + +#define ___EXPORT_SYMBOL(sym, sec) \ + ___export_symbol_common(sym, sec); \ __KSYMTAB_ENTRY(sym, sec) #endif @@ -95,6 +130,7 @@ struct kernel_symbol { * be reused in other execution contexts such as the UEFI stub or the * decompressor. */ +#define __EXPORT_SYMBOL_NS(sym, sec, ns) #define __EXPORT_SYMBOL(sym, sec) #elif defined(CONFIG_TRIM_UNUSED_KSYMS) @@ -121,15 +157,35 @@ struct kernel_symbol { #define __cond_export_sym_1(sym, sec) ___EXPORT_SYMBOL(sym, sec) #define __cond_export_sym_0(sym, sec) /* nothing */ +#define __EXPORT_SYMBOL_NS(sym, sec, ns) \ + __ksym_marker(sym); \ + __cond_export_ns_sym(sym, sec, ns, __is_defined(__KSYM_##sym)) +#define __cond_export_ns_sym(sym, sec, ns, conf) \ + ___cond_export_ns_sym(sym, sec, ns, conf) +#define ___cond_export_ns_sym(sym, sec, ns, enabled) \ + __cond_export_ns_sym_##enabled(sym, sec, ns) +#define __cond_export_ns_sym_1(sym, sec, ns) ___EXPORT_SYMBOL_NS(sym, sec, ns) +#define __cond_export_ns_sym_0(sym, sec, ns) /* nothing */ + #else -#define __EXPORT_SYMBOL(sym, sec) ___EXPORT_SYMBOL(sym, sec) +#define __EXPORT_SYMBOL_NS(sym,sec,ns) ___EXPORT_SYMBOL_NS(sym,sec,ns) +#define __EXPORT_SYMBOL(sym,sec) ___EXPORT_SYMBOL(sym,sec) #endif /* CONFIG_MODULES */ +#ifdef DEFAULT_SYMBOL_NAMESPACE +#undef __EXPORT_SYMBOL +#define __EXPORT_SYMBOL(sym, sec) \ + __EXPORT_SYMBOL_NS(sym, sec, DEFAULT_SYMBOL_NAMESPACE) +#endif + #define EXPORT_SYMBOL(sym) __EXPORT_SYMBOL(sym, "") #define EXPORT_SYMBOL_GPL(sym) __EXPORT_SYMBOL(sym, "_gpl") #define EXPORT_SYMBOL_GPL_FUTURE(sym) __EXPORT_SYMBOL(sym, "_gpl_future") +#define EXPORT_SYMBOL_NS(sym, ns) __EXPORT_SYMBOL_NS(sym, "", ns) +#define EXPORT_SYMBOL_NS_GPL(sym, ns) __EXPORT_SYMBOL_NS(sym, "_gpl", ns) + #ifdef CONFIG_UNUSED_SYMBOLS #define EXPORT_UNUSED_SYMBOL(sym) __EXPORT_SYMBOL(sym, "_unused") #define EXPORT_UNUSED_SYMBOL_GPL(sym) __EXPORT_SYMBOL(sym, "_unused_gpl") diff --git a/include/linux/module.h b/include/linux/module.h index 1455812dd325..b3611e749f72 100644 --- a/include/linux/module.h +++ b/include/linux/module.h @@ -280,6 +280,8 @@ struct notifier_block; #ifdef CONFIG_MODULES +#define MODULE_IMPORT_NS(ns) MODULE_INFO(import_ns, #ns) + extern int modules_disabled; /* for sysctl */ /* Get/put a kernel symbol (calls must be symmetric) */ void *__symbol_get(const char *symbol); diff --git a/init/Kconfig b/init/Kconfig index 058ba4e74250..57123594a7ca 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -2047,7 +2047,6 @@ config MODULE_SRCVERSION_ALL config MODULE_SIG bool "Module signature verification" - depends on MODULES select SYSTEM_DATA_VERIFICATION help Check modules for valid signatures upon load: the signature @@ -2124,7 +2123,6 @@ config MODULE_SIG_HASH config MODULE_COMPRESS bool "Compress modules on installation" - depends on MODULES help Compresses kernel modules when 'make modules_install' is run; gzip or @@ -2160,9 +2158,38 @@ config MODULE_COMPRESS_XZ endchoice +config MODULE_ALLOW_MISSING_NAMESPACE_IMPORTS + bool "Allow loading of modules with missing namespace imports" + help + Symbols exported with EXPORT_SYMBOL_NS*() are considered exported in + a namespace. A module that makes use of a symbol exported with such a + namespace is required to import the namespace via MODULE_IMPORT_NS(). + There is no technical reason to enforce correct namespace imports, + but it creates consistency between symbols defining namespaces and + users importing namespaces they make use of. This option relaxes this + requirement and lifts the enforcement when loading a module. + + If unsure, say N. + +config UNUSED_SYMBOLS + bool "Enable unused/obsolete exported symbols" + default y if X86 + help + Unused but exported symbols make the kernel needlessly bigger. For + that reason most of these unused exports will soon be removed. This + option is provided temporarily to provide a transition period in case + some external kernel module needs one of these symbols anyway. If you + encounter such a case in your module, consider if you are actually + using the right API. (rationale: since nobody in the kernel is using + this in a module, there is a pretty good chance it's actually the + wrong interface to use). If you really need the symbol, please send a + mail to the linux kernel mailing list mentioning the symbol and why + you really need it, and what the merge plan to the mainline kernel for + your module is. + config TRIM_UNUSED_KSYMS bool "Trim unused exported kernel symbols" - depends on MODULES && !UNUSED_SYMBOLS + depends on !UNUSED_SYMBOLS help The kernel and some modules make many symbols availa |