From bf5438fca2950b03c21ad868090cc1a8fcd49536 Mon Sep 17 00:00:00 2001 From: Jason Baron Date: Fri, 17 Sep 2010 11:09:00 -0400 Subject: jump label: Base patch for jump label base patch to implement 'jump labeling'. Based on a new 'asm goto' inline assembly gcc mechanism, we can now branch to labels from an 'asm goto' statment. This allows us to create a 'no-op' fastpath, which can subsequently be patched with a jump to the slowpath code. This is useful for code which might be rarely used, but which we'd like to be able to call, if needed. Tracepoints are the current usecase that these are being implemented for. Acked-by: David S. Miller Signed-off-by: Jason Baron LKML-Reference: [ cleaned up some formating ] Signed-off-by: Steven Rostedt --- include/linux/module.h | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) (limited to 'include/linux/module.h') diff --git a/include/linux/module.h b/include/linux/module.h index 8a6b9fdc7ffa..403ac26023ce 100644 --- a/include/linux/module.h +++ b/include/linux/module.h @@ -350,7 +350,10 @@ struct module struct tracepoint *tracepoints; unsigned int num_tracepoints; #endif - +#ifdef HAVE_JUMP_LABEL + struct jump_entry *jump_entries; + unsigned int num_jump_entries; +#endif #ifdef CONFIG_TRACING const char **trace_bprintk_fmt_start; unsigned int num_trace_bprintk_fmt; -- cgit v1.2.2 From 84e1c6bb38eb318e456558b610396d9f1afaabf0 Mon Sep 17 00:00:00 2001 From: matthieu castet Date: Tue, 16 Nov 2010 22:35:16 +0100 Subject: x86: Add RO/NX protection for loadable kernel modules This patch is a logical extension of the protection provided by CONFIG_DEBUG_RODATA to LKMs. The protection is provided by splitting module_core and module_init into three logical parts each and setting appropriate page access permissions for each individual section: 1. Code: RO+X 2. RO data: RO+NX 3. RW data: RW+NX In order to achieve proper protection, layout_sections() have been modified to align each of the three parts mentioned above onto page boundary. Next, the corresponding page access permissions are set right before successful exit from load_module(). Further, free_module() and sys_init_module have been modified to set module_core and module_init as RW+NX right before calling module_free(). By default, the original section layout and access flags are preserved. When compiled with CONFIG_DEBUG_SET_MODULE_RONX=y, the patch will page-align each group of sections to ensure that each page contains only one type of content and will enforce RO/NX for each group of pages. -v1: Initial proof-of-concept patch. -v2: The patch have been re-written to reduce the number of #ifdefs and to make it architecture-agnostic. Code formatting has also been corrected. -v3: Opportunistic RO/NX protection is now unconditional. Section page-alignment is enabled when CONFIG_DEBUG_RODATA=y. -v4: Removed most macros and improved coding style. -v5: Changed page-alignment and RO/NX section size calculation -v6: Fixed comments. Restricted RO/NX enforcement to x86 only -v7: Introduced CONFIG_DEBUG_SET_MODULE_RONX, added calls to set_all_modules_text_rw() and set_all_modules_text_ro() in ftrace -v8: updated for compatibility with linux 2.6.33-rc5 -v9: coding style fixes -v10: more coding style fixes -v11: minor adjustments for -tip -v12: minor adjustments for v2.6.35-rc2-tip -v13: minor adjustments for v2.6.37-rc1-tip Signed-off-by: Siarhei Liakh Signed-off-by: Xuxian Jiang Acked-by: Arjan van de Ven Reviewed-by: James Morris Signed-off-by: H. Peter Anvin Cc: Andi Kleen Cc: Rusty Russell Cc: Stephen Rothwell Cc: Dave Jones Cc: Kees Cook Cc: Linus Torvalds LKML-Reference: <4CE2F914.9070106@free.fr> [ minor cleanliness edits, -v14: build failure fix ] Signed-off-by: Ingo Molnar --- include/linux/module.h | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) (limited to 'include/linux/module.h') diff --git a/include/linux/module.h b/include/linux/module.h index b29e7458b966..ddaa689d71bd 100644 --- a/include/linux/module.h +++ b/include/linux/module.h @@ -308,6 +308,9 @@ struct module /* The size of the executable code in each section. */ unsigned int init_text_size, core_text_size; + /* Size of RO sections of the module (text+rodata) */ + unsigned int init_ro_size, core_ro_size; + /* Arch-specific module values */ struct mod_arch_specific arch; @@ -672,7 +675,6 @@ static inline int module_get_iter_tracepoints(struct tracepoint_iter *iter) { return 0; } - #endif /* CONFIG_MODULES */ #ifdef CONFIG_SYSFS @@ -687,6 +689,13 @@ extern int module_sysfs_initialized; #define __MODULE_STRING(x) __stringify(x) +#ifdef CONFIG_DEBUG_SET_MODULE_RONX +extern void set_all_modules_text_rw(void); +extern void set_all_modules_text_ro(void); +#else +static inline void set_all_modules_text_rw(void) { } +static inline void set_all_modules_text_ro(void) { } +#endif #ifdef CONFIG_GENERIC_BUG void module_bug_finalize(const Elf_Ehdr *, const Elf_Shdr *, -- cgit v1.2.2 From dfd62d1d84d83f9421792c78bcf72de9bc2bb603 Mon Sep 17 00:00:00 2001 From: Anders Kaseorg Date: Wed, 24 Nov 2010 15:21:10 -0600 Subject: module: Update prototype for ref_module (formerly use_module) Commit 9bea7f23952d5948f8e5dfdff4de09bb9981fb5f renamed use_module to ref_module (and changed its return value), but forgot to update this prototype in module.h. Signed-off-by: Anders Kaseorg Acked-by: WANG Cong Signed-off-by: Rusty Russell --- include/linux/module.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'include/linux/module.h') diff --git a/include/linux/module.h b/include/linux/module.h index b29e7458b966..7575bbbdf2a2 100644 --- a/include/linux/module.h +++ b/include/linux/module.h @@ -517,7 +517,7 @@ static inline void __module_get(struct module *module) #define symbol_put_addr(p) do { } while(0) #endif /* CONFIG_MODULE_UNLOAD */ -int use_module(struct module *a, struct module *b); +int ref_module(struct module *a, struct module *b); /* This is a #define so the string doesn't get put in every .o file */ #define module_name(mod) \ -- cgit v1.2.2 From e94965ed5beb23c6fabf7ed31f625e66d7ff28de Mon Sep 17 00:00:00 2001 From: Dmitry Torokhov Date: Wed, 15 Dec 2010 14:00:19 -0800 Subject: module: show version information for built-in modules in sysfs Currently only drivers that are built as modules have their versions shown in /sys/module//version, but this information might also be useful for built-in drivers as well. This especially important for drivers that do not define any parameters - such drivers, if built-in, are completely invisible from userspace. This patch changes MODULE_VERSION() macro so that in case when we are compiling built-in module, version information is stored in a separate section. Kernel then uses this data to create 'version' sysfs attribute in the same fashion it creates attributes for module parameters. Signed-off-by: Dmitry Torokhov Signed-off-by: Rusty Russell --- include/linux/module.h | 27 +++++++++++++++++++++++++++ 1 file changed, 27 insertions(+) (limited to 'include/linux/module.h') diff --git a/include/linux/module.h b/include/linux/module.h index 8b17fd8c790d..50efcd3ae850 100644 --- a/include/linux/module.h +++ b/include/linux/module.h @@ -58,6 +58,12 @@ struct module_attribute { void (*free)(struct module *); }; +struct module_version_attribute { + struct module_attribute mattr; + const char *module_name; + const char *version; +}; + struct module_kobject { struct kobject kobj; @@ -161,7 +167,28 @@ extern struct module __this_module; Using this automatically adds a checksum of the .c files and the local headers in "srcversion". */ + +#ifdef MODULE #define MODULE_VERSION(_version) MODULE_INFO(version, _version) +#else +#define MODULE_VERSION(_version) \ + extern ssize_t __modver_version_show(struct module_attribute *, \ + struct module *, char *); \ + static struct module_version_attribute __modver_version_attr \ + __used \ + __attribute__ ((__section__ ("__modver"),aligned(sizeof(void *)))) \ + = { \ + .mattr = { \ + .attr = { \ + .name = "version", \ + .mode = S_IRUGO, \ + }, \ + .show = __modver_version_show, \ + }, \ + .module_name = KBUILD_MODNAME, \ + .version = _version, \ + } +#endif /* Optional firmware file (or files) needed by the module * format is simply firmware file name. Multiple firmware -- cgit v1.2.2 From 3b90a5b292321b2acac3921f77046ae195aef53f Mon Sep 17 00:00:00 2001 From: Rusty Russell Date: Mon, 24 Jan 2011 14:32:51 -0600 Subject: module: fix linker error for MODULE_VERSION when !MODULE and CONFIG_SYSFS=n lib/built-in.o:(__modver+0x8): undefined reference to `__modver_version_show' lib/built-in.o:(__modver+0x2c): undefined reference to `__modver_version_show' Simplest to just not emit anything: if they've disabled SYSFS they probably want the smallest kernel possible. Reported-by: Randy Dunlap Signed-off-by: Rusty Russell --- include/linux/module.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'include/linux/module.h') diff --git a/include/linux/module.h b/include/linux/module.h index 50efcd3ae850..e7c6385c6683 100644 --- a/include/linux/module.h +++ b/include/linux/module.h @@ -168,7 +168,7 @@ extern struct module __this_module; local headers in "srcversion". */ -#ifdef MODULE +#if defined(MODULE) || !defined(CONFIG_SYSFS) #define MODULE_VERSION(_version) MODULE_INFO(version, _version) #else #define MODULE_VERSION(_version) \ -- cgit v1.2.2 From e4a9ea5ee7c8812a7bf0c3fb725ceeaa3d4c2fcc Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Thu, 27 Jan 2011 09:15:30 -0500 Subject: tracing: Replace trace_event struct array with pointer array Currently the trace_event structures are placed in the _ftrace_events section, and at link time, the linker makes one large array of all the trace_event structures. On boot up, this array is read (much like the initcall sections) and the events are processed. The problem is that there is no guarantee that gcc will place complex structures nicely together in an array format. Two structures in the same file may be placed awkwardly, because gcc has no clue that they are suppose to be in an array. A hack was used previous to force the alignment to 4, to pack the structures together. But this caused alignment issues with other architectures (sparc). Instead of packing the structures into an array, the structures' addresses are now put into the _ftrace_event section. As pointers are always the natural alignment, gcc should always pack them tightly together (otherwise initcall, extable, etc would also fail). By having the pointers to the structures in the section, we can still iterate the trace_events without causing unnecessary alignment problems with other architectures, or depending on the current behaviour of gcc that will likely change in the future just to tick us kernel developers off a little more. The _ftrace_event section is also moved into the .init.data section as it is now only needed at boot up. Suggested-by: David Miller Cc: Mathieu Desnoyers Acked-by: David S. Miller Signed-off-by: Steven Rostedt --- include/linux/module.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'include/linux/module.h') diff --git a/include/linux/module.h b/include/linux/module.h index e7c6385c6683..7695a303bb55 100644 --- a/include/linux/module.h +++ b/include/linux/module.h @@ -389,7 +389,7 @@ struct module unsigned int num_trace_bprintk_fmt; #endif #ifdef CONFIG_EVENT_TRACING - struct ftrace_event_call *trace_events; + struct ftrace_event_call **trace_events; unsigned int num_trace_events; #endif #ifdef CONFIG_FTRACE_MCOUNT_RECORD -- cgit v1.2.2 From 654986462939cd7ec18f276c6379a334dac106a7 Mon Sep 17 00:00:00 2001 From: Mathieu Desnoyers Date: Wed, 26 Jan 2011 17:26:22 -0500 Subject: tracepoints: Fix section alignment using pointer array Make the tracepoints more robust, making them solid enough to handle compiler changes by not relying on anything based on compiler-specific behavior with respect to structure alignment. Implement an approach proposed by David Miller: use an array of const pointers to refer to the individual structures, and export this pointer array through the linker script rather than the structures per se. It will consume 32 extra bytes per tracepoint (24 for structure padding and 8 for the pointers), but are less likely to break due to compiler changes. History: commit 7e066fb8 tracepoints: add DECLARE_TRACE() and DEFINE_TRACE() added the aligned(32) type and variable attribute to the tracepoint structures to deal with gcc happily aligning statically defined structures on 32-byte multiples. One attempt was to use a 8-byte alignment for tracepoint structures by applying both the variable and type attribute to tracepoint structures definitions and declarations. It worked fine with gcc 4.5.1, but broke with gcc 4.4.4 and 4.4.5. The reason is that the "aligned" attribute only specify the _minimum_ alignment for a structure, leaving both the compiler and the linker free to align on larger multiples. Because tracepoint.c expects the structures to be placed as an array within each section, up-alignment cause NULL-pointer exceptions due to the extra unexpected padding. (this patch applies on top of -tip) Signed-off-by: Mathieu Desnoyers Acked-by: David S. Miller LKML-Reference: <20110126222622.GA10794@Krystal> CC: Frederic Weisbecker CC: Ingo Molnar CC: Thomas Gleixner CC: Andrew Morton CC: Peter Zijlstra CC: Rusty Russell Signed-off-by: Steven Rostedt --- include/linux/module.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'include/linux/module.h') diff --git a/include/linux/module.h b/include/linux/module.h index 7695a303bb55..9bdf27c7615b 100644 --- a/include/linux/module.h +++ b/include/linux/module.h @@ -377,7 +377,7 @@ struct module keeping pointers to this stuff */ char *args; #ifdef CONFIG_TRACEPOINTS - struct tracepoint *tracepoints; + struct tracepoint * const *tracepoints_ptrs; unsigned int num_tracepoints; #endif #ifdef HAVE_JUMP_LABEL -- cgit v1.2.2 From 98562ad8cb03fa6b7ba7f50168cdb34a98abcc1d Mon Sep 17 00:00:00 2001 From: Dmitry Torokhov Date: Fri, 4 Feb 2011 13:30:10 -0800 Subject: module: explicitly align module_version_attribute structure We force particular alignment when we generate attribute structures when generation MODULE_VERSION() data and we need to make sure that this alignment is followed when we iterate over these structures, otherwise we may crash on platforms whose natural alignment is not sizeof(void *), such as m68k. Reported-by: Geert Uytterhoeven Signed-off-by: Dmitry Torokhov [ There are more issues here, but the fixes are incredibly ugly - Linus ] Signed-off-by: Linus Torvalds --- include/linux/module.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'include/linux/module.h') diff --git a/include/linux/module.h b/include/linux/module.h index 9bdf27c7615b..5de42043dff0 100644 --- a/include/linux/module.h +++ b/include/linux/module.h @@ -62,7 +62,7 @@ struct module_version_attribute { struct module_attribute mattr; const char *module_name; const char *version; -}; +} __attribute__ ((__aligned__(sizeof(void *)))); struct module_kobject { -- cgit v1.2.2 From b4bc842802db3314f9a657094da0450a903ea619 Mon Sep 17 00:00:00 2001 From: Dmitry Torokhov Date: Mon, 7 Feb 2011 16:02:25 -0800 Subject: module: deal with alignment issues in built-in module versions On m68k natural alignment is 2-byte boundary but we are trying to align structures in __modver section on sizeof(void *) boundary. This causes trouble when we try to access elements in this section in array-like fashion when create "version" attributes for built-in modules. Moreover, as DaveM said, we can't reliably put structures into independent objects, put them into a special section, and then expect array access over them (via the section boundaries) after linking the objects together to just "work" due to variable alignment choices in different situations. The only solution that seems to work reliably is to make an array of plain pointers to the objects in question and put those pointers in the special section. Reported-by: Geert Uytterhoeven Signed-off-by: Dmitry Torokhov Signed-off-by: Rusty Russell --- include/linux/module.h | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) (limited to 'include/linux/module.h') diff --git a/include/linux/module.h b/include/linux/module.h index 5de42043dff0..4cfebc211695 100644 --- a/include/linux/module.h +++ b/include/linux/module.h @@ -174,10 +174,7 @@ extern struct module __this_module; #define MODULE_VERSION(_version) \ extern ssize_t __modver_version_show(struct module_attribute *, \ struct module *, char *); \ - static struct module_version_attribute __modver_version_attr \ - __used \ - __attribute__ ((__section__ ("__modver"),aligned(sizeof(void *)))) \ - = { \ + static struct module_version_attribute ___modver_attr = { \ .mattr = { \ .attr = { \ .name = "version", \ @@ -187,7 +184,10 @@ extern struct module __this_module; }, \ .module_name = KBUILD_MODNAME, \ .version = _version, \ - } + }; \ + static const struct module_version_attribute \ + __used __attribute__ ((__section__ ("__modver"))) \ + * __moduleparam_const __modver_attr = &___modver_attr #endif /* Optional firmware file (or files) needed by the module -- cgit v1.2.2 From 9b73a5840c7d5f77e5766626716df13787cb258c Mon Sep 17 00:00:00 2001 From: Dmitry Torokhov Date: Mon, 7 Feb 2011 16:02:27 -0800 Subject: module: do not hide __modver_version_show declaration behind ifdef Doing so prevents the following warning from sparse: CHECK kernel/params.c kernel/params.c:817:9: warning: symbol '__modver_version_show' was not declared. Should it be static? since kernel/params.c is never compiled with MODULE being set. Signed-off-by: Dmitry Torokhov Signed-off-by: Rusty Russell --- include/linux/module.h | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) (limited to 'include/linux/module.h') diff --git a/include/linux/module.h b/include/linux/module.h index 4cfebc211695..23996ad147e7 100644 --- a/include/linux/module.h +++ b/include/linux/module.h @@ -64,6 +64,9 @@ struct module_version_attribute { const char *version; } __attribute__ ((__aligned__(sizeof(void *)))); +extern ssize_t __modver_version_show(struct module_attribute *, + struct module *, char *); + struct module_kobject { struct kobject kobj; @@ -172,8 +175,6 @@ extern struct module __this_module; #define MODULE_VERSION(_version) MODULE_INFO(version, _version) #else #define MODULE_VERSION(_version) \ - extern ssize_t __modver_version_show(struct module_attribute *, \ - struct module *, char *); \ static struct module_version_attribute ___modver_attr = { \ .mattr = { \ .attr = { \ -- cgit v1.2.2 From a288bd651f4180c224cfddf837a0416157a36661 Mon Sep 17 00:00:00 2001 From: Richard Kennedy Date: Thu, 19 May 2011 16:55:25 -0600 Subject: module: remove 64 bit alignment padding from struct module with CONFIG_TRACE* Reorder struct module to remove 24 bytes of alignment padding on 64 bit builds when the CONFIG_TRACE options are selected. This allows the structure to fit into one fewer cache lines, and its size drops from 592 to 568 on x86_64. Signed-off-by: Richard Kennedy Signed-off-by: Rusty Russell --- include/linux/module.h | 13 +++++++------ 1 file changed, 7 insertions(+), 6 deletions(-) (limited to 'include/linux/module.h') diff --git a/include/linux/module.h b/include/linux/module.h index 23996ad147e7..65cc6cc73ca8 100644 --- a/include/linux/module.h +++ b/include/linux/module.h @@ -368,34 +368,35 @@ struct module struct module_notes_attrs *notes_attrs; #endif + /* The command line arguments (may be mangled). People like + keeping pointers to this stuff */ + char *args; + #ifdef CONFIG_SMP /* Per-cpu data. */ void __percpu *percpu; unsigned int percpu_size; #endif - /* The command line arguments (may be mangled). People like - keeping pointers to this stuff */ - char *args; #ifdef CONFIG_TRACEPOINTS - struct tracepoint * const *tracepoints_ptrs; unsigned int num_tracepoints; + struct tracepoint * const *tracepoints_ptrs; #endif #ifdef HAVE_JUMP_LABEL struct jump_entry *jump_entries; unsigned int num_jump_entries; #endif #ifdef CONFIG_TRACING - const char **trace_bprintk_fmt_start; unsigned int num_trace_bprintk_fmt; + const char **trace_bprintk_fmt_start; #endif #ifdef CONFIG_EVENT_TRACING struct ftrace_event_call **trace_events; unsigned int num_trace_events; #endif #ifdef CONFIG_FTRACE_MCOUNT_RECORD - unsigned long *ftrace_callsites; unsigned int num_ftrace_callsites; + unsigned long *ftrace_callsites; #endif #ifdef CONFIG_MODULE_UNLOAD -- cgit v1.2.2 From de4d8d53465483168d6a627d409ee2d09d8e3308 Mon Sep 17 00:00:00 2001 From: Rusty Russell Date: Tue, 19 Apr 2011 21:49:58 +0200 Subject: module: each_symbol_section instead of each_symbol Instead of having a callback function for each symbol in the kernel, have a callback for each array of symbols. This eases the logic when we move to sorted symbols and binary search. Signed-off-by: Rusty Russell Signed-off-by: Alessio Igor Bogani --- include/linux/module.h | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) (limited to 'include/linux/module.h') diff --git a/include/linux/module.h b/include/linux/module.h index 65cc6cc73ca8..49f4ad0ddec2 100644 --- a/include/linux/module.h +++ b/include/linux/module.h @@ -477,8 +477,9 @@ const struct kernel_symbol *find_symbol(const char *name, bool warn); /* Walk the exported symbol table */ -bool each_symbol(bool (*fn)(const struct symsearch *arr, struct module *owner, - unsigned int symnum, void *data), void *data); +bool each_symbol_section(bool (*fn)(const struct symsearch *arr, + struct module *owner, + void *data), void *data); /* Returns 0 and fills in value, defined and namebuf, or -ERANGE if symnum out of range. */ -- cgit v1.2.2 From f02e8a6596b7dc9b2171f7ff5654039ef0950cdc Mon Sep 17 00:00:00 2001 From: Alessio Igor Bogani Date: Thu, 14 Apr 2011 14:59:39 +0200 Subject: module: Sort exported symbols This patch places every exported symbol in its own section (i.e. "___ksymtab+printk"). Thus the linker will use its SORT() directive to sort and finally merge all symbol in the right and final section (i.e. "__ksymtab"). The symbol prefixed archs use an underscore as prefix for symbols. To avoid collision we use a different character to create the temporary section names. This work was supported by a hardware donation from the CE Linux Forum. Signed-off-by: Alessio Igor Bogani Signed-off-by: Rusty Russell (folded in '+' fixup) Tested-by: Dirk Behme --- include/linux/module.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'include/linux/module.h') diff --git a/include/linux/module.h b/include/linux/module.h index 49f4ad0ddec2..d9ca2d5dc6d0 100644 --- a/include/linux/module.h +++ b/include/linux/module.h @@ -224,7 +224,7 @@ struct module_use { extern void *__crc_##sym __attribute__((weak)); \ static const unsigned long __kcrctab_##sym \ __used \ - __attribute__((section("__kcrctab" sec), unused)) \ + __attribute__((section("___kcrctab" sec "+" #sym), unused)) \ = (unsigned long) &__crc_##sym; #else #define __CRC_SYMBOL(sym, sec) @@ -239,7 +239,7 @@ struct module_use { = MODULE_SYMBOL_PREFIX #sym; \ static const struct kernel_symbol __ksymtab_##sym \ __used \ - __attribute__((section("__ksymtab" sec), unused)) \ + __attribute__((section("___ksymtab" sec "+" #sym), unused)) \ = { (unsigned long)&sym, __kstrtab_##sym } #define EXPORT_SYMBOL(sym) \ -- cgit v1.2.2