On 9/18/2023 2:24 PM, KP Singh wrote: > LSM hooks are currently invoked from a linked list as indirect calls > which are invoked using retpolines as a mitigation for speculative > attacks (Branch History / Target injection) and add extra overhead which > is especially bad in kernel hot paths: > > security_file_ioctl: > 0xffffffff814f0320 <+0>: endbr64 > 0xffffffff814f0324 <+4>: push %rbp > 0xffffffff814f0325 <+5>: push %r15 > 0xffffffff814f0327 <+7>: push %r14 > 0xffffffff814f0329 <+9>: push %rbx > 0xffffffff814f032a <+10>: mov %rdx,%rbx > 0xffffffff814f032d <+13>: mov %esi,%ebp > 0xffffffff814f032f <+15>: mov %rdi,%r14 > 0xffffffff814f0332 <+18>: mov $0xffffffff834a7030,%r15 > 0xffffffff814f0339 <+25>: mov (%r15),%r15 > 0xffffffff814f033c <+28>: test %r15,%r15 > 0xffffffff814f033f <+31>: je 0xffffffff814f0358 <security_file_ioctl+56> > 0xffffffff814f0341 <+33>: mov 0x18(%r15),%r11 > 0xffffffff814f0345 <+37>: mov %r14,%rdi > 0xffffffff814f0348 <+40>: mov %ebp,%esi > 0xffffffff814f034a <+42>: mov %rbx,%rdx > > 0xffffffff814f034d <+45>: call 0xffffffff81f742e0 <__x86_indirect_thunk_array+352> > ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ > > Indirect calls that use retpolines leading to overhead, not just due > to extra instruction but also branch misses. > > 0xffffffff814f0352 <+50>: test %eax,%eax > 0xffffffff814f0354 <+52>: je 0xffffffff814f0339 <security_file_ioctl+25> > 0xffffffff814f0356 <+54>: jmp 0xffffffff814f035a <security_file_ioctl+58> > 0xffffffff814f0358 <+56>: xor %eax,%eax > 0xffffffff814f035a <+58>: pop %rbx > 0xffffffff814f035b <+59>: pop %r14 > 0xffffffff814f035d <+61>: pop %r15 > 0xffffffff814f035f <+63>: pop %rbp > 0xffffffff814f0360 <+64>: jmp 0xffffffff81f747c4 <__x86_return_thunk> > > The indirect calls are not really needed as one knows the addresses of > enabled LSM callbacks at boot time and only the order can possibly > change at boot time with the lsm= kernel command line parameter. > > An array of static calls is defined per LSM hook and the static calls > are updated at boot time once the order has been determined. > > A static key guards whether an LSM static call is enabled or not, > without this static key, for LSM hooks that return an int, the presence > of the hook that returns a default value can create side-effects which > has resulted in bugs [1]. > > With the hook now exposed as a static call, one can see that the > retpolines are no longer there and the LSM callbacks are invoked > directly: > > security_file_ioctl: > 0xffffffff818f0ca0 <+0>: endbr64 > 0xffffffff818f0ca4 <+4>: nopl 0x0(%rax,%rax,1) > 0xffffffff818f0ca9 <+9>: push %rbp > 0xffffffff818f0caa <+10>: push %r14 > 0xffffffff818f0cac <+12>: push %rbx > 0xffffffff818f0cad <+13>: mov %rdx,%rbx > 0xffffffff818f0cb0 <+16>: mov %esi,%ebp > 0xffffffff818f0cb2 <+18>: mov %rdi,%r14 > 0xffffffff818f0cb5 <+21>: jmp 0xffffffff818f0cc7 <security_file_ioctl+39> > ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ > Static key enabled for SELinux > > 0xffffffff818f0cb7 <+23>: jmp 0xffffffff818f0cde <security_file_ioctl+62> > ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ > > Static key enabled for BPF LSM. This is something that is changed to > default to false to avoid the existing side effect issues of BPF LSM > [1] in a subsequent patch. > > 0xffffffff818f0cb9 <+25>: xor %eax,%eax > 0xffffffff818f0cbb <+27>: xchg %ax,%ax > 0xffffffff818f0cbd <+29>: pop %rbx > 0xffffffff818f0cbe <+30>: pop %r14 > 0xffffffff818f0cc0 <+32>: pop %rbp > 0xffffffff818f0cc1 <+33>: cs jmp 0xffffffff82c00000 <__x86_return_thunk> > 0xffffffff818f0cc7 <+39>: endbr64 > 0xffffffff818f0ccb <+43>: mov %r14,%rdi > 0xffffffff818f0cce <+46>: mov %ebp,%esi > 0xffffffff818f0cd0 <+48>: mov %rbx,%rdx > 0xffffffff818f0cd3 <+51>: call 0xffffffff81903230 <selinux_file_ioctl> > ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ > Direct call to SELinux. > > 0xffffffff818f0cd8 <+56>: test %eax,%eax > 0xffffffff818f0cda <+58>: jne 0xffffffff818f0cbd <security_file_ioctl+29> > 0xffffffff818f0cdc <+60>: jmp 0xffffffff818f0cb7 <security_file_ioctl+23> > 0xffffffff818f0cde <+62>: endbr64 > 0xffffffff818f0ce2 <+66>: mov %r14,%rdi > 0xffffffff818f0ce5 <+69>: mov %ebp,%esi > 0xffffffff818f0ce7 <+71>: mov %rbx,%rdx > 0xffffffff818f0cea <+74>: call 0xffffffff8141e220 <bpf_lsm_file_ioctl> > ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ > Direct call to BPF LSM. > > 0xffffffff818f0cef <+79>: test %eax,%eax > 0xffffffff818f0cf1 <+81>: jne 0xffffffff818f0cbd <security_file_ioctl+29> > 0xffffffff818f0cf3 <+83>: jmp 0xffffffff818f0cb9 <security_file_ioctl+25> > 0xffffffff818f0cf5 <+85>: endbr64 > 0xffffffff818f0cf9 <+89>: mov %r14,%rdi > 0xffffffff818f0cfc <+92>: mov %ebp,%esi > 0xffffffff818f0cfe <+94>: mov %rbx,%rdx > 0xffffffff818f0d01 <+97>: pop %rbx > 0xffffffff818f0d02 <+98>: pop %r14 > 0xffffffff818f0d04 <+100>: pop %rbp > 0xffffffff818f0d05 <+101>: ret > 0xffffffff818f0d06 <+102>: int3 > 0xffffffff818f0d07 <+103>: int3 > 0xffffffff818f0d08 <+104>: int3 > 0xffffffff818f0d09 <+105>: int3 > > While this patch uses static_branch_unlikely indicating that an LSM hook > is likely to be not present, a subsequent makes it configurable. In most > cases this is still a better choice as even when an LSM with one hook is > added, empty slots are created for all LSM hooks (especially when many > LSMs that do not initialize most hooks are present on the system). > > There are some hooks that don't use the call_int_hook and > call_void_hook. These hooks are updated to use a new macro called > security_for_each_hook where the lsm_callback is directly invoked as an > indirect call. Currently, there are no performance sensitive hooks that > use the security_for_each_hook macro. However, if, some performance > sensitive hooks are discovered, these can be updated to use static calls > with loop unrolling as well using a custom macro. > > [1] https://lore.kernel.org/linux-security-module/20220609234601.2026362-1-kpsingh@xxxxxxxxxx/ > > Signed-off-by: KP Singh <kpsingh@xxxxxxxxxx> Good job on reducing the impact in security.c. Reviewed-by: Casey Schaufler <casey@xxxxxxxxxxxxxxxx> > --- > include/linux/lsm_hooks.h | 70 +++++++++++-- > security/security.c | 208 +++++++++++++++++++++++++------------- > 2 files changed, 199 insertions(+), 79 deletions(-) > > diff --git a/include/linux/lsm_hooks.h b/include/linux/lsm_hooks.h > index dcb5e5b5eb13..eb9afe93496f 100644 > --- a/include/linux/lsm_hooks.h > +++ b/include/linux/lsm_hooks.h > @@ -29,26 +29,77 @@ > #include <linux/init.h> > #include <linux/rculist.h> > #include <linux/xattr.h> > +#include <linux/static_call.h> > +#include <linux/unroll.h> > +#include <linux/jump_label.h> > +#include <linux/lsm_count.h> > + > +#define SECURITY_HOOK_ACTIVE_KEY(HOOK, IDX) security_hook_active_##HOOK##_##IDX > + > +/* > + * Identifier for the LSM static calls. > + * HOOK is an LSM hook as defined in linux/lsm_hookdefs.h > + * IDX is the index of the static call. 0 <= NUM < MAX_LSM_COUNT > + */ > +#define LSM_STATIC_CALL(HOOK, IDX) lsm_static_call_##HOOK##_##IDX > + > +/* > + * Call the macro M for each LSM hook MAX_LSM_COUNT times. > + */ > +#define LSM_LOOP_UNROLL(M, ...) \ > +do { \ > + UNROLL(MAX_LSM_COUNT, M, __VA_ARGS__) \ > +} while (0) > + > +#define LSM_DEFINE_UNROLL(M, ...) UNROLL(MAX_LSM_COUNT, M, __VA_ARGS__) > > union security_list_options { > #define LSM_HOOK(RET, DEFAULT, NAME, ...) RET (*NAME)(__VA_ARGS__); > #include "lsm_hook_defs.h" > #undef LSM_HOOK > + void *lsm_callback; > }; > > -struct security_hook_heads { > - #define LSM_HOOK(RET, DEFAULT, NAME, ...) struct hlist_head NAME; > - #include "lsm_hook_defs.h" > +/* > + * @key: static call key as defined by STATIC_CALL_KEY > + * @trampoline: static call trampoline as defined by STATIC_CALL_TRAMP > + * @hl: The security_hook_list as initialized by the owning LSM. > + * @active: Enabled when the static call has an LSM hook associated. > + */ > +struct lsm_static_call { > + struct static_call_key *key; > + void *trampoline; > + struct security_hook_list *hl; > + /* this needs to be true or false based on what the key defaults to */ > + struct static_key_false *active; > +}; > + > +/* > + * Table of the static calls for each LSM hook. > + * Once the LSMs are initialized, their callbacks will be copied to these > + * tables such that the calls are filled backwards (from last to first). > + * This way, we can jump directly to the first used static call, and execute > + * all of them after. This essentially makes the entry point > + * dynamic to adapt the number of static calls to the number of callbacks. > + */ > +struct lsm_static_calls_table { > + #define LSM_HOOK(RET, DEFAULT, NAME, ...) \ > + struct lsm_static_call NAME[MAX_LSM_COUNT]; > + #include <linux/lsm_hook_defs.h> > #undef LSM_HOOK > } __randomize_layout; > > /* > * Security module hook list structure. > * For use with generic list macros for common operations. > + * > + * struct security_hook_list - Contents of a cacheable, mappable object. > + * @scalls: The beginning of the array of static calls assigned to this hook. > + * @hook: The callback for the hook. > + * @lsm: The name of the lsm that owns this hook. > */ > struct security_hook_list { > - struct hlist_node list; > - struct hlist_head *head; > + struct lsm_static_call *scalls; > union security_list_options hook; > const char *lsm; > } __randomize_layout; > @@ -97,10 +148,12 @@ static inline struct xattr *lsm_get_xattr_slot(struct xattr *xattrs, > * care of the common case and reduces the amount of > * text involved. > */ > -#define LSM_HOOK_INIT(HEAD, HOOK) \ > - { .head = &security_hook_heads.HEAD, .hook = { .HEAD = HOOK } } > +#define LSM_HOOK_INIT(NAME, CALLBACK) \ > + { \ > + .scalls = static_calls_table.NAME, \ > + .hook = { .NAME = CALLBACK } \ > + } > > -extern struct security_hook_heads security_hook_heads; > extern char *lsm_names; > > extern void security_add_hooks(struct security_hook_list *hooks, int count, > @@ -138,5 +191,6 @@ extern struct lsm_info __start_early_lsm_info[], __end_early_lsm_info[]; > __aligned(sizeof(unsigned long)) > > extern int lsm_inode_alloc(struct inode *inode); > +extern struct lsm_static_calls_table static_calls_table __ro_after_init; > > #endif /* ! __LINUX_LSM_HOOKS_H */ > diff --git a/security/security.c b/security/security.c > index 7b0052e96806..c2c2cf6b711f 100644 > --- a/security/security.c > +++ b/security/security.c > @@ -30,6 +30,8 @@ > #include <linux/string.h> > #include <linux/msg.h> > #include <net/flow.h> > +#include <linux/static_call.h> > +#include <linux/jump_label.h> > > /* How many LSMs were built into the kernel? */ > #define LSM_COUNT (__end_lsm_info - __start_lsm_info) > @@ -73,7 +75,6 @@ const char *const lockdown_reasons[LOCKDOWN_CONFIDENTIALITY_MAX + 1] = { > [LOCKDOWN_CONFIDENTIALITY_MAX] = "confidentiality", > }; > > -struct security_hook_heads security_hook_heads __ro_after_init; > static BLOCKING_NOTIFIER_HEAD(blocking_lsm_notifier_chain); > > static struct kmem_cache *lsm_file_cache; > @@ -92,6 +93,51 @@ static __initconst const char *const builtin_lsm_order = CONFIG_LSM; > static __initdata struct lsm_info **ordered_lsms; > static __initdata struct lsm_info *exclusive; > > + > +#ifdef CONFIG_HAVE_STATIC_CALL > +#define LSM_HOOK_TRAMP(NAME, NUM) \ > + &STATIC_CALL_TRAMP(LSM_STATIC_CALL(NAME, NUM)) > +#else > +#define LSM_HOOK_TRAMP(NAME, NUM) NULL > +#endif > + > +/* > + * Define static calls and static keys for each LSM hook. > + */ > + > +#define DEFINE_LSM_STATIC_CALL(NUM, NAME, RET, ...) \ > + DEFINE_STATIC_CALL_NULL(LSM_STATIC_CALL(NAME, NUM), \ > + *((RET(*)(__VA_ARGS__))NULL)); \ > + DEFINE_STATIC_KEY_FALSE(SECURITY_HOOK_ACTIVE_KEY(NAME, NUM)); > + > +#define LSM_HOOK(RET, DEFAULT, NAME, ...) \ > + LSM_DEFINE_UNROLL(DEFINE_LSM_STATIC_CALL, NAME, RET, __VA_ARGS__) > +#include <linux/lsm_hook_defs.h> > +#undef LSM_HOOK > +#undef DEFINE_LSM_STATIC_CALL > + > +/* > + * Initialise a table of static calls for each LSM hook. > + * DEFINE_STATIC_CALL_NULL invocation above generates a key (STATIC_CALL_KEY) > + * and a trampoline (STATIC_CALL_TRAMP) which are used to call > + * __static_call_update when updating the static call. > + */ > +struct lsm_static_calls_table static_calls_table __ro_after_init = { > +#define INIT_LSM_STATIC_CALL(NUM, NAME) \ > + (struct lsm_static_call) { \ > + .key = &STATIC_CALL_KEY(LSM_STATIC_CALL(NAME, NUM)), \ > + .trampoline = LSM_HOOK_TRAMP(NAME, NUM), \ > + .active = &SECURITY_HOOK_ACTIVE_KEY(NAME, NUM), \ > + }, > +#define LSM_HOOK(RET, DEFAULT, NAME, ...) \ > + .NAME = { \ > + LSM_DEFINE_UNROLL(INIT_LSM_STATIC_CALL, NAME) \ > + }, > +#include <linux/lsm_hook_defs.h> > +#undef LSM_HOOK > +#undef INIT_LSM_STATIC_CALL > +}; > + > static __initdata bool debug; > #define init_debug(...) \ > do { \ > @@ -152,7 +198,7 @@ static void __init append_ordered_lsm(struct lsm_info *lsm, const char *from) > if (exists_ordered_lsm(lsm)) > return; > > - if (WARN(last_lsm == LSM_COUNT, "%s: out of LSM slots!?\n", from)) > + if (WARN(last_lsm == LSM_COUNT, "%s: out of LSM static calls!?\n", from)) > return; > > /* Enable this LSM, if it is not already set. */ > @@ -325,6 +371,25 @@ static void __init ordered_lsm_parse(const char *order, const char *origin) > kfree(sep); > } > > +static void __init lsm_static_call_init(struct security_hook_list *hl) > +{ > + struct lsm_static_call *scall = hl->scalls; > + int i; > + > + for (i = 0; i < MAX_LSM_COUNT; i++) { > + /* Update the first static call that is not used yet */ > + if (!scall->hl) { > + __static_call_update(scall->key, scall->trampoline, > + hl->hook.lsm_callback); > + scall->hl = hl; > + static_branch_enable(scall->active); > + return; > + } > + scall++; > + } > + panic("%s - Ran out of static slots.\n", __func__); > +} > + > static void __init lsm_early_cred(struct cred *cred); > static void __init lsm_early_task(struct task_struct *task); > > @@ -404,11 +469,6 @@ int __init early_security_init(void) > { > struct lsm_info *lsm; > > -#define LSM_HOOK(RET, DEFAULT, NAME, ...) \ > - INIT_HLIST_HEAD(&security_hook_heads.NAME); > -#include "linux/lsm_hook_defs.h" > -#undef LSM_HOOK > - > for (lsm = __start_early_lsm_info; lsm < __end_early_lsm_info; lsm++) { > if (!lsm->enabled) > lsm->enabled = &lsm_enabled_true; > @@ -524,7 +584,7 @@ void __init security_add_hooks(struct security_hook_list *hooks, int count, > > for (i = 0; i < count; i++) { > hooks[i].lsm = lsm; > - hlist_add_tail_rcu(&hooks[i].list, hooks[i].head); > + lsm_static_call_init(&hooks[i]); > } > > /* > @@ -762,29 +822,41 @@ static int lsm_superblock_alloc(struct super_block *sb) > * call_int_hook: > * This is a hook that returns a value. > */ > +#define __CALL_STATIC_VOID(NUM, HOOK, ...) \ > +do { \ > + if (static_branch_unlikely(&SECURITY_HOOK_ACTIVE_KEY(HOOK, NUM))) { \ > + static_call(LSM_STATIC_CALL(HOOK, NUM))(__VA_ARGS__); \ > + } \ > +} while (0); > > -#define call_void_hook(FUNC, ...) \ > - do { \ > - struct security_hook_list *P; \ > - \ > - hlist_for_each_entry(P, &security_hook_heads.FUNC, list) \ > - P->hook.FUNC(__VA_ARGS__); \ > +#define call_void_hook(FUNC, ...) \ > + do { \ > + LSM_LOOP_UNROLL(__CALL_STATIC_VOID, FUNC, __VA_ARGS__); \ > } while (0) > > -#define call_int_hook(FUNC, IRC, ...) ({ \ > - int RC = IRC; \ > - do { \ > - struct security_hook_list *P; \ > - \ > - hlist_for_each_entry(P, &security_hook_heads.FUNC, list) { \ > - RC = P->hook.FUNC(__VA_ARGS__); \ > - if (RC != 0) \ > - break; \ > - } \ > - } while (0); \ > - RC; \ > +#define __CALL_STATIC_INT(NUM, R, HOOK, LABEL, ...) \ > +do { \ > + if (static_branch_unlikely(&SECURITY_HOOK_ACTIVE_KEY(HOOK, NUM))) { \ > + R = static_call(LSM_STATIC_CALL(HOOK, NUM))(__VA_ARGS__); \ > + if (R != 0) \ > + goto LABEL; \ > + } \ > +} while (0); > + > +#define call_int_hook(FUNC, IRC, ...) \ > +({ \ > + __label__ out; \ > + int RC = IRC; \ > + LSM_LOOP_UNROLL(__CALL_STATIC_INT, RC, FUNC, out, __VA_ARGS__); \ > +out: \ > + RC; \ > }) > > +#define lsm_for_each_hook(scall, NAME) \ > + for (scall = static_calls_table.NAME; \ > + scall - static_calls_table.NAME < MAX_LSM_COUNT; scall++) \ > + if (static_key_enabled(&scall->active->key)) > + > /* Security operations */ > > /** > @@ -1020,7 +1092,7 @@ int security_settime64(const struct timespec64 *ts, const struct timezone *tz) > */ > int security_vm_enough_memory_mm(struct mm_struct *mm, long pages) > { > - struct security_hook_list *hp; > + struct lsm_static_call *scall; > int cap_sys_admin = 1; > int rc; > > @@ -1031,8 +1103,8 @@ int security_vm_enough_memory_mm(struct mm_struct *mm, long pages) > * agree that it should be set it will. If any module > * thinks it should not be set it won't. > */ > - hlist_for_each_entry(hp, &security_hook_heads.vm_enough_memory, list) { > - rc = hp->hook.vm_enough_memory(mm, pages); > + lsm_for_each_hook(scall, vm_enough_memory) { > + rc = scall->hl->hook.vm_enough_memory(mm, pages); > if (rc <= 0) { > cap_sys_admin = 0; > break; > @@ -1184,13 +1256,12 @@ int security_fs_context_dup(struct fs_context *fc, struct fs_context *src_fc) > int security_fs_context_parse_param(struct fs_context *fc, > struct fs_parameter *param) > { > - struct security_hook_list *hp; > + struct lsm_static_call *scall; > int trc; > int rc = -ENOPARAM; > > - hlist_for_each_entry(hp, &security_hook_heads.fs_context_parse_param, > - list) { > - trc = hp->hook.fs_context_parse_param(fc, param); > + lsm_for_each_hook(scall, fs_context_parse_param) { > + trc = scall->hl->hook.fs_context_parse_param(fc, param); > if (trc == 0) > rc = 0; > else if (trc != -ENOPARAM) > @@ -1553,19 +1624,19 @@ int security_dentry_init_security(struct dentry *dentry, int mode, > const char **xattr_name, void **ctx, > u32 *ctxlen) > { > - struct security_hook_list *hp; > + struct lsm_static_call *scall; > int rc; > > /* > * Only one module will provide a security context. > */ > - hlist_for_each_entry(hp, &security_hook_heads.dentry_init_security, > - list) { > - rc = hp->hook.dentry_init_security(dentry, mode, name, > + lsm_for_each_hook(scall, dentry_init_security) { > + rc = scall->hl->hook.dentry_init_security(dentry, mode, name, > xattr_name, ctx, ctxlen); > if (rc != LSM_RET_DEFAULT(dentry_init_security)) > return rc; > } > + > return LSM_RET_DEFAULT(dentry_init_security); > } > EXPORT_SYMBOL(security_dentry_init_security); > @@ -1625,7 +1696,7 @@ int security_inode_init_security(struct inode *inode, struct inode *dir, > const struct qstr *qstr, > const initxattrs initxattrs, void *fs_data) > { > - struct security_hook_list *hp; > + struct lsm_static_call *scall; > struct xattr *new_xattrs = NULL; > int ret = -EOPNOTSUPP, xattr_count = 0; > > @@ -1643,9 +1714,8 @@ int security_inode_init_security(struct inode *inode, struct inode *dir, > return -ENOMEM; > } > > - hlist_for_each_entry(hp, &security_hook_heads.inode_init_security, > - list) { > - ret = hp->hook.inode_init_security(inode, dir, qstr, new_xattrs, > + lsm_for_each_hook(scall, inode_init_security) { > + ret = scall->hl->hook.inode_init_security(inode, dir, qstr, new_xattrs, > &xattr_count); > if (ret && ret != -EOPNOTSUPP) > goto out; > @@ -2405,7 +2475,7 @@ int security_inode_getsecurity(struct mnt_idmap *idmap, > struct inode *inode, const char *name, > void **buffer, bool alloc) > { > - struct security_hook_list *hp; > + struct lsm_static_call *scall; > int rc; > > if (unlikely(IS_PRIVATE(inode))) > @@ -2413,9 +2483,8 @@ int security_inode_getsecurity(struct mnt_idmap *idmap, > /* > * Only one module will provide an attribute with a given name. > */ > - hlist_for_each_entry(hp, &security_hook_heads.inode_getsecurity, list) { > - rc = hp->hook.inode_getsecurity(idmap, inode, name, buffer, > - alloc); > + lsm_for_each_hook(scall, inode_getsecurity) { > + rc = scall->hl->hook.inode_getsecurity(idmap, inode, name, buffer, alloc); > if (rc != LSM_RET_DEFAULT(inode_getsecurity)) > return rc; > } > @@ -2440,7 +2509,7 @@ int security_inode_getsecurity(struct mnt_idmap *idmap, > int security_inode_setsecurity(struct inode *inode, const char *name, > const void *value, size_t size, int flags) > { > - struct security_hook_list *hp; > + struct lsm_static_call *scall; > int rc; > > if (unlikely(IS_PRIVATE(inode))) > @@ -2448,9 +2517,8 @@ int security_inode_setsecurity(struct inode *inode, const char *name, > /* > * Only one module will provide an attribute with a given name. > */ > - hlist_for_each_entry(hp, &security_hook_heads.inode_setsecurity, list) { > - rc = hp->hook.inode_setsecurity(inode, name, value, size, > - flags); > + lsm_for_each_hook(scall, inode_setsecurity) { > + rc = scall->hl->hook.inode_setsecurity(inode, name, value, size, flags); > if (rc != LSM_RET_DEFAULT(inode_setsecurity)) > return rc; > } > @@ -2524,7 +2592,7 @@ EXPORT_SYMBOL(security_inode_copy_up); > */ > int security_inode_copy_up_xattr(const char *name) > { > - struct security_hook_list *hp; > + struct lsm_static_call *scall; > int rc; > > /* > @@ -2532,9 +2600,8 @@ int security_inode_copy_up_xattr(const char *name) > * xattr), -EOPNOTSUPP if it does not know anything about the xattr or > * any other error code in case of an error. > */ > - hlist_for_each_entry(hp, > - &security_hook_heads.inode_copy_up_xattr, list) { > - rc = hp->hook.inode_copy_up_xattr(name); > + lsm_for_each_hook(scall, inode_copy_up_xattr) { > + rc = scall->hl->hook.inode_copy_up_xattr(name); > if (rc != LSM_RET_DEFAULT(inode_copy_up_xattr)) > return rc; > } > @@ -3414,10 +3481,10 @@ int security_task_prctl(int option, unsigned long arg2, unsigned long arg3, > { > int thisrc; > int rc = LSM_RET_DEFAULT(task_prctl); > - struct security_hook_list *hp; > + struct lsm_static_call *scall; > > - hlist_for_each_entry(hp, &security_hook_heads.task_prctl, list) { > - thisrc = hp->hook.task_prctl(option, arg2, arg3, arg4, arg5); > + lsm_for_each_hook(scall, task_prctl) { > + thisrc = scall->hl->hook.task_prctl(option, arg2, arg3, arg4, arg5); > if (thisrc != LSM_RET_DEFAULT(task_prctl)) { > rc = thisrc; > if (thisrc != 0) > @@ -3814,12 +3881,12 @@ EXPORT_SYMBOL(security_d_instantiate); > int security_getprocattr(struct task_struct *p, const char *lsm, > const char *name, char **value) > { > - struct security_hook_list *hp; > + struct lsm_static_call *scall; > > - hlist_for_each_entry(hp, &security_hook_heads.getprocattr, list) { > - if (lsm != NULL && strcmp(lsm, hp->lsm)) > + lsm_for_each_hook(scall, getprocattr) { > + if (lsm != NULL && strcmp(lsm, scall->hl->lsm)) > continue; > - return hp->hook.getprocattr(p, name, value); > + return scall->hl->hook.getprocattr(p, name, value); > } > return LSM_RET_DEFAULT(getprocattr); > } > @@ -3839,12 +3906,12 @@ int security_getprocattr(struct task_struct *p, const char *lsm, > int security_setprocattr(const char *lsm, const char *name, void *value, > size_t size) > { > - struct security_hook_list *hp; > + struct lsm_static_call *scall; > > - hlist_for_each_entry(hp, &security_hook_heads.setprocattr, list) { > - if (lsm != NULL && strcmp(lsm, hp->lsm)) > + lsm_for_each_hook(scall, setprocattr) { > + if (lsm != NULL && strcmp(lsm, scall->hl->lsm)) > continue; > - return hp->hook.setprocattr(name, value, size); > + return scall->hl->hook.setprocattr(name, value, size); > } > return LSM_RET_DEFAULT(setprocattr); > } > @@ -3896,15 +3963,15 @@ EXPORT_SYMBOL(security_ismaclabel); > */ > int security_secid_to_secctx(u32 secid, char **secdata, u32 *seclen) > { > - struct security_hook_list *hp; > + struct lsm_static_call *scall; > int rc; > > /* > * Currently, only one LSM can implement secid_to_secctx (i.e this > * LSM hook is not "stackable"). > */ > - hlist_for_each_entry(hp, &security_hook_heads.secid_to_secctx, list) { > - rc = hp->hook.secid_to_secctx(secid, secdata, seclen); > + lsm_for_each_hook(scall, secid_to_secctx) { > + rc = scall->hl->hook.secid_to_secctx(secid, secdata, seclen); > if (rc != LSM_RET_DEFAULT(secid_to_secctx)) > return rc; > } > @@ -4947,7 +5014,7 @@ int security_xfrm_state_pol_flow_match(struct xfrm_state *x, > struct xfrm_policy *xp, > const struct flowi_common *flic) > { > - struct security_hook_list *hp; > + struct lsm_static_call *scall; > int rc = LSM_RET_DEFAULT(xfrm_state_pol_flow_match); > > /* > @@ -4959,9 +5026,8 @@ int security_xfrm_state_pol_flow_match(struct xfrm_state *x, > * For speed optimization, we explicitly break the loop rather than > * using the macro > */ > - hlist_for_each_entry(hp, &security_hook_heads.xfrm_state_pol_flow_match, > - list) { > - rc = hp->hook.xfrm_state_pol_flow_match(x, xp, flic); > + lsm_for_each_hook(scall, xfrm_state_pol_flow_match) { > + rc = scall->hl->hook.xfrm_state_pol_flow_match(x, xp, flic); > break; > } > return rc;
