From c017b4be3e84176cab10eca5e6c4faeb8cfc6f3e Mon Sep 17 00:00:00 2001 From: Catalin Marinas Date: Wed, 28 Oct 2009 13:33:09 +0000 Subject: kmemleak: Simplify the kmemleak_scan_area() function prototype This function was taking non-necessary arguments which can be determined by kmemleak. The patch also modifies the calling sites. Signed-off-by: Catalin Marinas Cc: Pekka Enberg Cc: Christoph Lameter Cc: 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 8b7d8805819d..1eb952097077 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -2043,9 +2043,7 @@ static void kmemleak_load_module(struct module *mod, Elf_Ehdr *hdr, unsigned int i; /* only scan the sections containing data */ - kmemleak_scan_area(mod->module_core, (unsigned long)mod - - (unsigned long)mod->module_core, - sizeof(struct module), GFP_KERNEL); + kmemleak_scan_area(mod, sizeof(struct module), GFP_KERNEL); for (i = 1; i < hdr->e_shnum; i++) { if (!(sechdrs[i].sh_flags & SHF_ALLOC)) @@ -2054,8 +2052,7 @@ static void kmemleak_load_module(struct module *mod, Elf_Ehdr *hdr, && strncmp(secstrings + sechdrs[i].sh_name, ".bss", 4) != 0) continue; - kmemleak_scan_area(mod->module_core, sechdrs[i].sh_addr - - (unsigned long)mod->module_core, + kmemleak_scan_area((void *)sechdrs[i].sh_addr, sechdrs[i].sh_size, GFP_KERNEL); } } -- cgit v1.2.3 From a6f5aa1ea05686ad6e84593a00a04161e6dfb3a3 Mon Sep 17 00:00:00 2001 From: Catalin Marinas Date: Wed, 28 Oct 2009 13:33:10 +0000 Subject: kmemleak: Scan the _ftrace_events section in modules This section contains pointers to allocated objects and not scanning it leads to false positives. Reported-by: Zdenek Kabelac Acked-by: Rusty Russell Signed-off-by: Catalin Marinas --- kernel/module.c | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'kernel/module.c') diff --git a/kernel/module.c b/kernel/module.c index 1eb952097077..dd29ba43c34f 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -2380,6 +2380,12 @@ static noinline struct module *load_module(void __user *umod, "_ftrace_events", sizeof(*mod->trace_events), &mod->num_trace_events); + /* + * This section contains pointers to allocated objects in the trace + * code and not scanning it leads to false positives. + */ + kmemleak_scan_area(mod->trace_events, sizeof(*mod->trace_events) * + mod->num_trace_events, GFP_KERNEL); #endif #ifdef CONFIG_FTRACE_MCOUNT_RECORD /* sechdrs[0].sh_size is always zero */ -- cgit v1.2.3 From d4703aefdbc8f9f347f6dcefcddd791294314eb7 Mon Sep 17 00:00:00 2001 From: Rusty Russell Date: Tue, 15 Dec 2009 16:28:32 -0600 Subject: module: handle ppc64 relocating kcrctabs when CONFIG_RELOCATABLE=y powerpc applies relocations to the kcrctab. They're absolute symbols, but it's not completely unreasonable: other archs may too, but the relocation is often 0. http://lists.ozlabs.org/pipermail/linuxppc-dev/2009-November/077972.html Inspired-by: Neil Horman Signed-off-by: Rusty Russell Tested-by: Neil Horman Acked-by: Paul Mackerras --- kernel/module.c | 28 +++++++++++++++++++++------- 1 file changed, 21 insertions(+), 7 deletions(-) (limited to 'kernel/module.c') diff --git a/kernel/module.c b/kernel/module.c index 12afc5a3ddd3..a65dc787a27b 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -880,11 +880,23 @@ static int try_to_force_load(struct module *mod, const char *reason) } #ifdef CONFIG_MODVERSIONS +/* If the arch applies (non-zero) relocations to kernel kcrctab, unapply it. */ +static unsigned long maybe_relocated(unsigned long crc, + const struct module *crc_owner) +{ +#ifdef ARCH_RELOCATES_KCRCTAB + if (crc_owner == NULL) + return crc - (unsigned long)reloc_start; +#endif + return crc; +} + static int check_version(Elf_Shdr *sechdrs, unsigned int versindex, const char *symname, struct module *mod, - const unsigned long *crc) + const unsigned long *crc, + const struct module *crc_owner) { unsigned int i, num_versions; struct modversion_info *versions; @@ -905,10 +917,10 @@ static int check_version(Elf_Shdr *sechdrs, if (strcmp(versions[i].name, symname) != 0) continue; - if (versions[i].crc == *crc) + if (versions[i].crc == maybe_relocated(*crc, crc_owner)) return 1; DEBUGP("Found checksum %lX vs module %lX\n", - *crc, versions[i].crc); + maybe_relocated(*crc, crc_owner), versions[i].crc); goto bad_version; } @@ -931,7 +943,8 @@ static inline int check_modstruct_version(Elf_Shdr *sechdrs, if (!find_symbol(MODULE_SYMBOL_PREFIX "module_layout", NULL, &crc, true, false)) BUG(); - return check_version(sechdrs, versindex, "module_layout", mod, crc); + return check_version(sechdrs, versindex, "module_layout", mod, crc, + NULL); } /* First part is kernel version, which we ignore if module has crcs. */ @@ -949,7 +962,8 @@ static inline int check_version(Elf_Shdr *sechdrs, unsigned int versindex, const char *symname, struct module *mod, - const unsigned long *crc) + const unsigned long *crc, + const struct module *crc_owner) { return 1; } @@ -984,8 +998,8 @@ static const struct kernel_symbol *resolve_symbol(Elf_Shdr *sechdrs, /* use_module can fail due to OOM, or module initialization or unloading */ if (sym) { - if (!check_version(sechdrs, versindex, name, mod, crc) || - !use_module(mod, owner)) + if (!check_version(sechdrs, versindex, name, mod, crc, owner) + || !use_module(mod, owner)) sym = NULL; } return sym; -- cgit v1.2.3 From 10b465aaf9536ee5a16652fa0700740183d48ec9 Mon Sep 17 00:00:00 2001 From: Ben Hutchings Date: Sat, 19 Dec 2009 14:43:01 +0000 Subject: modules: Skip empty sections when exporting section notes Commit 35dead4 "modules: don't export section names of empty sections via sysfs" changed the set of sections that have attributes, but did not change the iteration over these attributes in add_notes_attrs(). This can lead to add_notes_attrs() creating attributes with the wrong names or with null name pointers. Introduce a sect_empty() function and use it in both add_sect_attrs() and add_notes_attrs(). Reported-by: Martin Michlmayr Signed-off-by: Ben Hutchings Tested-by: Martin Michlmayr Cc: stable@kernel.org Signed-off-by: Rusty Russell Signed-off-by: Linus Torvalds --- kernel/module.c | 17 ++++++++++------- 1 file changed, 10 insertions(+), 7 deletions(-) (limited to 'kernel/module.c') diff --git a/kernel/module.c b/kernel/module.c index e96b8ed1cb6a..f82386bd9ee9 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -1010,6 +1010,12 @@ static const struct kernel_symbol *resolve_symbol(Elf_Shdr *sechdrs, * J. Corbet */ #if defined(CONFIG_KALLSYMS) && defined(CONFIG_SYSFS) + +static inline bool sect_empty(const Elf_Shdr *sect) +{ + return !(sect->sh_flags & SHF_ALLOC) || sect->sh_size == 0; +} + struct module_sect_attr { struct module_attribute mattr; @@ -1051,8 +1057,7 @@ static void add_sect_attrs(struct module *mod, unsigned int nsect, /* Count loaded sections and allocate structures */ for (i = 0; i < nsect; i++) - if (sechdrs[i].sh_flags & SHF_ALLOC - && sechdrs[i].sh_size) + if (!sect_empty(&sechdrs[i])) nloaded++; size[0] = ALIGN(sizeof(*sect_attrs) + nloaded * sizeof(sect_attrs->attrs[0]), @@ -1070,9 +1075,7 @@ static void add_sect_attrs(struct module *mod, unsigned int nsect, sattr = §_attrs->attrs[0]; gattr = §_attrs->grp.attrs[0]; for (i = 0; i < nsect; i++) { - if (! (sechdrs[i].sh_flags & SHF_ALLOC)) - continue; - if (!sechdrs[i].sh_size) + if (sect_empty(&sechdrs[i])) continue; sattr->address = sechdrs[i].sh_addr; sattr->name = kstrdup(secstrings + sechdrs[i].sh_name, @@ -1156,7 +1159,7 @@ static void add_notes_attrs(struct module *mod, unsigned int nsect, /* Count notes sections and allocate structures. */ notes = 0; for (i = 0; i < nsect; i++) - if ((sechdrs[i].sh_flags & SHF_ALLOC) && + if (!sect_empty(&sechdrs[i]) && (sechdrs[i].sh_type == SHT_NOTE)) ++notes; @@ -1172,7 +1175,7 @@ static void add_notes_attrs(struct module *mod, unsigned int nsect, notes_attrs->notes = notes; nattr = ¬es_attrs->attrs[0]; for (loaded = i = 0; i < nsect; ++i) { - if (!(sechdrs[i].sh_flags & SHF_ALLOC)) + if (sect_empty(&sechdrs[i])) continue; if (sechdrs[i].sh_type == SHT_NOTE) { nattr->attr.name = mod->sect_attrs->attrs[loaded].name; -- cgit v1.2.3