From 7816c45bf13255157c00fb8aca86cb64d825e878 Mon Sep 17 00:00:00 2001 From: Roland Vossen Date: Thu, 7 Apr 2011 11:20:58 +0200 Subject: modules: Enabled dynamic debugging for staging modules Driver modules from the staging directory are marked 'tainted' by module.c. Subsequently, tainted modules are denied dynamic debugging. This is unwanted behavior, since staging modules should be able to use the dynamic debugging mechanism. Please merge this also into the staging-linus branch. Signed-off-by: Roland Vossen Acked-by: Jason Baron Signed-off-by: Greg Kroah-Hartman --- kernel/module.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'kernel/module.c') diff --git a/kernel/module.c b/kernel/module.c index d5938a5c19c4..4d5c16aae745 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -2790,7 +2790,7 @@ static struct module *load_module(void __user *umod, } /* This has to be done once we're sure module name is unique. */ - if (!mod->taints) + if (!mod->taints || mod->taints == (1U<taints) + if (!mod->taints || mod->taints == (1U< Date: Tue, 8 Mar 2011 22:01:47 +0800 Subject: minor ANSI prototype sparse fix Fix function prototype to be ANSI-C compliant, consistent with other function prototypes, addressing a sparse warning. Signed-off-by: Daniel J Blueman Signed-off-by: Rusty Russell --- kernel/module.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'kernel/module.c') diff --git a/kernel/module.c b/kernel/module.c index d5938a5c19c4..523c40b71777 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -1627,7 +1627,7 @@ void unset_section_ro_nx(struct module *mod, void *module_region) } /* Iterate through all modules and set each module's text as RW */ -void set_all_modules_text_rw() +void set_all_modules_text_rw(void) { struct module *mod; @@ -1648,7 +1648,7 @@ void set_all_modules_text_rw() } /* Iterate through all modules and set each module's text as RO */ -void set_all_modules_text_ro() +void set_all_modules_text_ro(void) { struct module *mod; -- cgit v1.2.3 From 4d10380e720a3ce19dbe88d0133f66ded07b6a8f Mon Sep 17 00:00:00 2001 From: Jan Glauber Date: Thu, 19 May 2011 16:55:25 -0600 Subject: module: zero mod->init_ro_size after init is freed. Reset mod->init_ro_size to zero after the init part of a module is unloaded. Otherwise we need to check if module->init is NULL in the unprotect functions in the next patch. Signed-off-by: Jan Glauber Signed-off-by: Rusty Russell --- kernel/module.c | 1 + 1 file changed, 1 insertion(+) (limited to 'kernel/module.c') diff --git a/kernel/module.c b/kernel/module.c index 523c40b71777..92112c91b7e9 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -2935,6 +2935,7 @@ SYSCALL_DEFINE3(init_module, void __user *, umod, module_free(mod, mod->module_init); mod->module_init = NULL; mod->init_size = 0; + mod->init_ro_size = 0; mod->init_text_size = 0; mutex_unlock(&module_mutex); -- cgit v1.2.3 From 448694a1d50432be63aafccb42d6f54d8cf3d02c Mon Sep 17 00:00:00 2001 From: Jan Glauber Date: Thu, 19 May 2011 16:55:26 -0600 Subject: module: undo module RONX protection correctly. While debugging I stumbled over two problems in the code that protects module pages. First issue is that disabling the protection before freeing init or unload of a module is not symmetric with the enablement. For instance, if pages are set to RO the page range from module_core to module_core + core_ro_size is protected. If a module is unloaded the page range from module_core to module_core + core_size is set back to RW. So pages that were not set to RO are also changed to RW. This is not critical but IMHO it should be symmetric. Second issue is that while set_memory_rw & set_memory_ro are used for RO/RW changes only set_memory_nx is involved for NX/X. One would await that the inverse function is called when the NX protection should be removed, which is not the case here, unless I'm missing something. Signed-off-by: Jan Glauber Signed-off-by: Rusty Russell --- kernel/module.c | 25 +++++++++++++------------ 1 file changed, 13 insertions(+), 12 deletions(-) (limited to 'kernel/module.c') diff --git a/kernel/module.c b/kernel/module.c index 92112c91b7e9..b99dcebc980d 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -1607,22 +1607,23 @@ static void set_section_ro_nx(void *base, } } -/* Setting memory back to RW+NX before releasing it */ +/* Setting memory back to W+X before releasing it */ void unset_section_ro_nx(struct module *mod, void *module_region) { - unsigned long total_pages; - if (mod->module_core == module_region) { - /* Set core as NX+RW */ - total_pages = MOD_NUMBER_OF_PAGES(mod->module_core, mod->core_size); - set_memory_nx((unsigned long)mod->module_core, total_pages); - set_memory_rw((unsigned long)mod->module_core, total_pages); - + set_page_attributes(mod->module_core + mod->core_text_size, + mod->module_core + mod->core_size, + set_memory_x); + set_page_attributes(mod->module_core, + mod->module_core + mod->core_ro_size, + set_memory_rw); } else if (mod->module_init == module_region) { - /* Set init as NX+RW */ - total_pages = MOD_NUMBER_OF_PAGES(mod->module_init, mod->init_size); - set_memory_nx((unsigned long)mod->module_init, total_pages); - set_memory_rw((unsigned long)mod->module_init, total_pages); + set_page_attributes(mod->module_init + mod->init_text_size, + mod->module_init + mod->init_size, + set_memory_x); + set_page_attributes(mod->module_init, + mod->module_init + mod->init_ro_size, + set_memory_rw); } } -- cgit v1.2.3 From 01526ed0830643bd53a8434c3068e4c077e1b09d Mon Sep 17 00:00:00 2001 From: Jan Glauber Date: Thu, 19 May 2011 16:55:26 -0600 Subject: module: split unset_section_ro_nx function. Split the unprotect function into a function per section to make the code more readable and add the missing static declaration. Signed-off-by: Jan Glauber Signed-off-by: Rusty Russell --- kernel/module.c | 45 +++++++++++++++++++++++---------------------- 1 file changed, 23 insertions(+), 22 deletions(-) (limited to 'kernel/module.c') diff --git a/kernel/module.c b/kernel/module.c index b99dcebc980d..0e6f97f43c88 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -1607,24 +1607,24 @@ static void set_section_ro_nx(void *base, } } -/* Setting memory back to W+X before releasing it */ -void unset_section_ro_nx(struct module *mod, void *module_region) -{ - if (mod->module_core == module_region) { - set_page_attributes(mod->module_core + mod->core_text_size, - mod->module_core + mod->core_size, - set_memory_x); - set_page_attributes(mod->module_core, - mod->module_core + mod->core_ro_size, - set_memory_rw); - } else if (mod->module_init == module_region) { - set_page_attributes(mod->module_init + mod->init_text_size, - mod->module_init + mod->init_size, - set_memory_x); - set_page_attributes(mod->module_init, - mod->module_init + mod->init_ro_size, - set_memory_rw); - } +static void unset_module_core_ro_nx(struct module *mod) +{ + set_page_attributes(mod->module_core + mod->core_text_size, + mod->module_core + mod->core_size, + set_memory_x); + set_page_attributes(mod->module_core, + mod->module_core + mod->core_ro_size, + set_memory_rw); +} + +static void unset_module_init_ro_nx(struct module *mod) +{ + set_page_attributes(mod->module_init + mod->init_text_size, + mod->module_init + mod->init_size, + set_memory_x); + set_page_attributes(mod->module_init, + mod->module_init + mod->init_ro_size, + set_memory_rw); } /* Iterate through all modules and set each module's text as RW */ @@ -1670,7 +1670,8 @@ void set_all_modules_text_ro(void) } #else static inline void set_section_ro_nx(void *base, unsigned long text_size, unsigned long ro_size, unsigned long total_size) { } -static inline void unset_section_ro_nx(struct module *mod, void *module_region) { } +static void unset_module_core_ro_nx(struct module *mod) { } +static void unset_module_init_ro_nx(struct module *mod) { } #endif /* Free a module, remove from lists, etc. */ @@ -1697,7 +1698,7 @@ static void free_module(struct module *mod) destroy_params(mod->kp, mod->num_kp); /* This may be NULL, but that's OK */ - unset_section_ro_nx(mod, mod->module_init); + unset_module_init_ro_nx(mod); module_free(mod, mod->module_init); kfree(mod->args); percpu_modfree(mod); @@ -1706,7 +1707,7 @@ static void free_module(struct module *mod) lockdep_free_key_range(mod->module_core, mod->core_size); /* Finally, free the core (containing the module structure) */ - unset_section_ro_nx(mod, mod->module_core); + unset_module_core_ro_nx(mod); module_free(mod, mod->module_core); #ifdef CONFIG_MPU @@ -2932,7 +2933,7 @@ SYSCALL_DEFINE3(init_module, void __user *, umod, mod->symtab = mod->core_symtab; mod->strtab = mod->core_strtab; #endif - unset_section_ro_nx(mod, mod->module_init); + unset_module_init_ro_nx(mod); module_free(mod, mod->module_init); mod->module_init = NULL; mod->init_size = 0; -- cgit v1.2.3 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 --- kernel/module.c | 42 +++++++++++++++++++++++++++--------------- 1 file changed, 27 insertions(+), 15 deletions(-) (limited to 'kernel/module.c') diff --git a/kernel/module.c b/kernel/module.c index 0e6f97f43c88..e8aa462301e7 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -240,23 +240,24 @@ static bool each_symbol_in_section(const struct symsearch *arr, struct module *owner, bool (*fn)(const struct symsearch *syms, struct module *owner, - unsigned int symnum, void *data), + void *data), void *data) { - unsigned int i, j; + unsigned int j; for (j = 0; j < arrsize; j++) { - for (i = 0; i < arr[j].stop - arr[j].start; i++) - if (fn(&arr[j], owner, i, data)) - return true; + if (fn(&arr[j], owner, data)) + return true; } return false; } /* Returns true as soon as fn returns true, otherwise false. */ -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) { struct module *mod; static const struct symsearch arr[] = { @@ -309,7 +310,7 @@ bool each_symbol(bool (*fn)(const struct symsearch *arr, struct module *owner, } return false; } -EXPORT_SYMBOL_GPL(each_symbol); +EXPORT_SYMBOL_GPL(each_symbol_section); struct find_symbol_arg { /* Input */ @@ -323,15 +324,12 @@ struct find_symbol_arg { const struct kernel_symbol *sym; }; -static bool find_symbol_in_section(const struct symsearch *syms, - struct module *owner, - unsigned int symnum, void *data) +static bool check_symbol(const struct symsearch *syms, + struct module *owner, + unsigned int symnum, void *data) { struct find_symbol_arg *fsa = data; - if (strcmp(syms->start[symnum].name, fsa->name) != 0) - return false; - if (!fsa->gplok) { if (syms->licence == GPL_ONLY) return false; @@ -365,6 +363,20 @@ static bool find_symbol_in_section(const struct symsearch *syms, return true; } +static bool find_symbol_in_section(const struct symsearch *syms, + struct module *owner, + void *data) +{ + struct find_symbol_arg *fsa = data; + unsigned int i; + + for (i = 0; i < syms->stop - syms->start; i++) { + if (strcmp(syms->start[i].name, fsa->name) == 0) + return check_symbol(syms, owner, i, data); + } + return false; +} + /* Find a symbol and return it, along with, (optional) crc and * (optional) module which owns it. Needs preempt disabled or module_mutex. */ const struct kernel_symbol *find_symbol(const char *name, @@ -379,7 +391,7 @@ const struct kernel_symbol *find_symbol(const char *name, fsa.gplok = gplok; fsa.warn = warn; - if (each_symbol(find_symbol_in_section, &fsa)) { + if (each_symbol_section(find_symbol_in_section, &fsa)) { if (owner) *owner = fsa.owner; if (crc) -- cgit v1.2.3 From 403ed27846aa126ecf0b842b5b179c506b9d989c Mon Sep 17 00:00:00 2001 From: Alessio Igor Bogani Date: Wed, 20 Apr 2011 11:10:52 +0200 Subject: module: Use the binary search for symbols resolution Takes advantage of the order and locates symbols using binary search. This work was supported by a hardware donation from the CE Linux Forum. Signed-off-by: Alessio Igor Bogani Signed-off-by: Rusty Russell Tested-by: Dirk Behme --- kernel/module.c | 21 ++++++++++++++++----- 1 file changed, 16 insertions(+), 5 deletions(-) (limited to 'kernel/module.c') diff --git a/kernel/module.c b/kernel/module.c index e8aa462301e7..d1db8eb56ad4 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -57,6 +57,7 @@ #include #include #include +#include #define CREATE_TRACE_POINTS #include @@ -363,17 +364,27 @@ static bool check_symbol(const struct symsearch *syms, return true; } +static int cmp_name(const void *va, const void *vb) +{ + const char *a; + const struct kernel_symbol *b; + a = va; b = vb; + return strcmp(a, b->name); +} + static bool find_symbol_in_section(const struct symsearch *syms, struct module *owner, void *data) { struct find_symbol_arg *fsa = data; - unsigned int i; + struct kernel_symbol *sym; + + sym = bsearch(fsa->name, syms->start, syms->stop - syms->start, + sizeof(struct kernel_symbol), cmp_name); + + if (sym != NULL && check_symbol(syms, owner, sym - syms->start, data)) + return true; - for (i = 0; i < syms->stop - syms->start; i++) { - if (strcmp(syms->start[i].name, fsa->name) == 0) - return check_symbol(syms, owner, i, data); - } return false; } -- cgit v1.2.3 From 9d63487f86115b1d3ef69670043bcf2b83c4d227 Mon Sep 17 00:00:00 2001 From: Alessio Igor Bogani Date: Wed, 18 May 2011 22:35:59 +0200 Subject: module: Use binary search in lookup_symbol() The function is_exported() with its helper function lookup_symbol() are used to verify if a provided symbol is effectively exported by the kernel or by the modules. Now that both have their symbols sorted we can replace a linear search with a binary search which provide a considerably speed-up. This work was supported by a hardware donation from the CE Linux Forum. Signed-off-by: Alessio Igor Bogani Acked-by: Greg Kroah-Hartman Signed-off-by: Rusty Russell --- kernel/module.c | 7 ++----- 1 file changed, 2 insertions(+), 5 deletions(-) (limited to 'kernel/module.c') diff --git a/kernel/module.c b/kernel/module.c index d1db8eb56ad4..22879725678d 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -2055,11 +2055,8 @@ static const struct kernel_symbol *lookup_symbol(const char *name, const struct kernel_symbol *start, const struct kernel_symbol *stop) { - const struct kernel_symbol *ks = start; - for (; ks < stop; ks++) - if (strcmp(ks->name, name) == 0) - return ks; - return NULL; + return bsearch(name, start, stop - start, + sizeof(struct kernel_symbol), cmp_name); } static int is_exported(const char *name, unsigned long value, -- cgit v1.2.3