From 8f0e96ee118781602ab67282b66a0b25fcf7692b Mon Sep 17 00:00:00 2001 From: John Crispin Date: Tue, 7 Jul 2015 13:48:27 +0000 Subject: [PATCH] mips: Free memory when load_module fails (#14453) The mips reloc patch introduced new allocations which were done before add_unformed_module but never freed them in case of an error. A new hook in Linux 3.19 called module_arch_freeing_init can be used for freeing memory which were allocated during this init phase. The problem can be seen when trying to load a module (via busybox insmod) when it was already loaded. free -m for i in `seq 1 100`; do /sbin/insmod /lib/modules/*/ath9k.ko >& /dev/null done free -m This simple loop would leak ~3.2 MB. Signed-off-by: Sven Eckelmann SVN-Revision: 46247 --- ...ing_init-new-hook-for-archs-before-m.patch | 182 ++++++++++++++++++ .../patches-3.18/305-mips_module_reloc.patch | 11 +- .../patches-4.0/305-mips_module_reloc.patch | 11 +- .../patches-4.1/305-mips_module_reloc.patch | 11 +- 4 files changed, 200 insertions(+), 15 deletions(-) create mode 100644 target/linux/generic/patches-3.18/099-module_arch_freeing_init-new-hook-for-archs-before-m.patch diff --git a/target/linux/generic/patches-3.18/099-module_arch_freeing_init-new-hook-for-archs-before-m.patch b/target/linux/generic/patches-3.18/099-module_arch_freeing_init-new-hook-for-archs-before-m.patch new file mode 100644 index 0000000000..05cb2585ed --- /dev/null +++ b/target/linux/generic/patches-3.18/099-module_arch_freeing_init-new-hook-for-archs-before-m.patch @@ -0,0 +1,182 @@ +From: Rusty Russell +Date: Tue, 20 Jan 2015 09:07:04 +1030 +Subject: [PATCH] module_arch_freeing_init(): new hook for archs before module->module_init freed. + +Archs have been abusing module_free() to clean up their arch-specific +allocations. Since module_free() is also (ab)used by BPF and trace code, +let's keep it to simple allocations, and provide a hook called before +that. + +This means that avr32, ia64, parisc and s390 no longer need to implement +their own module_free() at all. avr32 doesn't need module_finalize() +either. + +Signed-off-by: Rusty Russell +Cc: Chris Metcalf +Cc: Haavard Skinnemoen +Cc: Hans-Christian Egtvedt +Cc: Tony Luck +Cc: Fenghua Yu +Cc: "James E.J. Bottomley" +Cc: Helge Deller +Cc: Martin Schwidefsky +Cc: Heiko Carstens +Cc: linux-kernel@vger.kernel.org +Cc: linux-ia64@vger.kernel.org +Cc: linux-parisc@vger.kernel.org +Cc: linux-s390@vger.kernel.org + +Origin: backport, https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=d453cded05ee219b77815ea194dc36efa5398bca +--- + arch/avr32/kernel/module.c | 13 +------------ + arch/ia64/kernel/module.c | 6 ++---- + arch/parisc/kernel/module.c | 6 +----- + arch/s390/kernel/module.c | 10 +++------- + arch/tile/kernel/module.c | 2 +- + include/linux/moduleloader.h | 2 ++ + kernel/module.c | 7 +++++++ + 7 files changed, 17 insertions(+), 29 deletions(-) + +--- a/arch/avr32/kernel/module.c ++++ b/arch/avr32/kernel/module.c +@@ -19,12 +19,10 @@ + #include + #include + +-void module_free(struct module *mod, void *module_region) ++void module_arch_freeing_init(struct module *mod) + { + vfree(mod->arch.syminfo); + mod->arch.syminfo = NULL; +- +- vfree(module_region); + } + + static inline int check_rela(Elf32_Rela *rela, struct module *module, +@@ -291,12 +289,3 @@ int apply_relocate_add(Elf32_Shdr *sechd + + return ret; + } +- +-int module_finalize(const Elf_Ehdr *hdr, const Elf_Shdr *sechdrs, +- struct module *module) +-{ +- vfree(module->arch.syminfo); +- module->arch.syminfo = NULL; +- +- return 0; +-} +--- a/arch/ia64/kernel/module.c ++++ b/arch/ia64/kernel/module.c +@@ -305,14 +305,12 @@ plt_target (struct plt_entry *plt) + #endif /* !USE_BRL */ + + void +-module_free (struct module *mod, void *module_region) ++module_arch_freeing_init (struct module *mod) + { +- if (mod && mod->arch.init_unw_table && +- module_region == mod->module_init) { ++ if (mod->arch.init_unw_table) { + unw_remove_unwind_table(mod->arch.init_unw_table); + mod->arch.init_unw_table = NULL; + } +- vfree(module_region); + } + + /* Have we already seen one of these relocations? */ +--- a/arch/parisc/kernel/module.c ++++ b/arch/parisc/kernel/module.c +@@ -298,14 +298,10 @@ static inline unsigned long count_stubs( + } + #endif + +- +-/* Free memory returned from module_alloc */ +-void module_free(struct module *mod, void *module_region) ++void module_arch_freeing_init(struct module *mod) + { + kfree(mod->arch.section); + mod->arch.section = NULL; +- +- vfree(module_region); + } + + /* Additional bytes needed in front of individual sections */ +--- a/arch/s390/kernel/module.c ++++ b/arch/s390/kernel/module.c +@@ -55,14 +55,10 @@ void *module_alloc(unsigned long size) + } + #endif + +-/* Free memory returned from module_alloc */ +-void module_free(struct module *mod, void *module_region) ++void module_arch_freeing_init(struct module *mod) + { +- if (mod) { +- vfree(mod->arch.syminfo); +- mod->arch.syminfo = NULL; +- } +- vfree(module_region); ++ vfree(mod->arch.syminfo); ++ mod->arch.syminfo = NULL; + } + + static void +--- a/arch/tile/kernel/module.c ++++ b/arch/tile/kernel/module.c +@@ -83,7 +83,7 @@ void module_free(struct module *mod, voi + 0, 0, 0, NULL, NULL, 0); + + /* +- * FIXME: If module_region == mod->module_init, trim exception ++ * FIXME: Add module_arch_freeing_init to trim exception + * table entries. + */ + } +--- a/include/linux/moduleloader.h ++++ b/include/linux/moduleloader.h +@@ -80,4 +80,6 @@ int module_finalize(const Elf_Ehdr *hdr, + /* Any cleanup needed when module leaves. */ + void module_arch_cleanup(struct module *mod); + ++/* Any cleanup before freeing mod->module_init */ ++void module_arch_freeing_init(struct module *mod); + #endif +--- a/kernel/module.c ++++ b/kernel/module.c +@@ -1855,6 +1855,10 @@ void __weak module_arch_cleanup(struct m + { + } + ++void __weak module_arch_freeing_init(struct module *mod) ++{ ++} ++ + /* Free a module, remove from lists, etc. */ + static void free_module(struct module *mod) + { +@@ -1880,6 +1884,7 @@ static void free_module(struct module *m + + /* This may be NULL, but that's OK */ + unset_module_init_ro_nx(mod); ++ module_arch_freeing_init(mod); + module_free(mod, mod->module_init); + kfree(mod->args); + percpu_modfree(mod); +@@ -2983,6 +2988,7 @@ out: + static void module_deallocate(struct module *mod, struct load_info *info) + { + percpu_modfree(mod); ++ module_arch_freeing_init(mod); + module_free(mod, mod->module_init); + module_free(mod, mod->module_core); + } +@@ -3122,6 +3128,7 @@ static int do_init_module(struct module + mod->strtab = mod->core_strtab; + #endif + unset_module_init_ro_nx(mod); ++ module_arch_freeing_init(mod); + module_free(mod, mod->module_init); + mod->module_init = NULL; + mod->init_size = 0; diff --git a/target/linux/generic/patches-3.18/305-mips_module_reloc.patch b/target/linux/generic/patches-3.18/305-mips_module_reloc.patch index 41cf80671b..f8ca91401a 100644 --- a/target/linux/generic/patches-3.18/305-mips_module_reloc.patch +++ b/target/linux/generic/patches-3.18/305-mips_module_reloc.patch @@ -317,7 +317,7 @@ return 0; } -@@ -287,11 +529,32 @@ int module_finalize(const Elf_Ehdr *hdr, +@@ -287,9 +529,33 @@ int module_finalize(const Elf_Ehdr *hdr, list_add(&me->arch.dbe_list, &dbe_list); spin_unlock_irq(&dbe_lock); } @@ -336,8 +336,8 @@ return 0; } - void module_arch_cleanup(struct module *mod) - { ++void module_arch_freeing_init(struct module *mod) ++{ + if (mod->arch.phys_plt_tbl) { + __module_free(mod->arch.phys_plt_tbl); + mod->arch.phys_plt_tbl = NULL; @@ -346,7 +346,8 @@ + __module_free(mod->arch.virt_plt_tbl); + mod->arch.virt_plt_tbl = NULL; + } ++} + + void module_arch_cleanup(struct module *mod) + { spin_lock_irq(&dbe_lock); - list_del(&mod->arch.dbe_list); - spin_unlock_irq(&dbe_lock); diff --git a/target/linux/generic/patches-4.0/305-mips_module_reloc.patch b/target/linux/generic/patches-4.0/305-mips_module_reloc.patch index 87c205c7db..8b3975fe09 100644 --- a/target/linux/generic/patches-4.0/305-mips_module_reloc.patch +++ b/target/linux/generic/patches-4.0/305-mips_module_reloc.patch @@ -316,7 +316,7 @@ return 0; } -@@ -287,11 +528,32 @@ int module_finalize(const Elf_Ehdr *hdr, +@@ -287,9 +528,33 @@ int module_finalize(const Elf_Ehdr *hdr, list_add(&me->arch.dbe_list, &dbe_list); spin_unlock_irq(&dbe_lock); } @@ -335,8 +335,8 @@ return 0; } - void module_arch_cleanup(struct module *mod) - { ++void module_arch_freeing_init(struct module *mod) ++{ + if (mod->arch.phys_plt_tbl) { + __module_free(mod->arch.phys_plt_tbl); + mod->arch.phys_plt_tbl = NULL; @@ -345,7 +345,8 @@ + __module_free(mod->arch.virt_plt_tbl); + mod->arch.virt_plt_tbl = NULL; + } ++} + + void module_arch_cleanup(struct module *mod) + { spin_lock_irq(&dbe_lock); - list_del(&mod->arch.dbe_list); - spin_unlock_irq(&dbe_lock); diff --git a/target/linux/generic/patches-4.1/305-mips_module_reloc.patch b/target/linux/generic/patches-4.1/305-mips_module_reloc.patch index 87c205c7db..8b3975fe09 100644 --- a/target/linux/generic/patches-4.1/305-mips_module_reloc.patch +++ b/target/linux/generic/patches-4.1/305-mips_module_reloc.patch @@ -316,7 +316,7 @@ return 0; } -@@ -287,11 +528,32 @@ int module_finalize(const Elf_Ehdr *hdr, +@@ -287,9 +528,33 @@ int module_finalize(const Elf_Ehdr *hdr, list_add(&me->arch.dbe_list, &dbe_list); spin_unlock_irq(&dbe_lock); } @@ -335,8 +335,8 @@ return 0; } - void module_arch_cleanup(struct module *mod) - { ++void module_arch_freeing_init(struct module *mod) ++{ + if (mod->arch.phys_plt_tbl) { + __module_free(mod->arch.phys_plt_tbl); + mod->arch.phys_plt_tbl = NULL; @@ -345,7 +345,8 @@ + __module_free(mod->arch.virt_plt_tbl); + mod->arch.virt_plt_tbl = NULL; + } ++} + + void module_arch_cleanup(struct module *mod) + { spin_lock_irq(&dbe_lock); - list_del(&mod->arch.dbe_list); - spin_unlock_irq(&dbe_lock); -- 2.25.1