diff options
author | Jiri Kosina <jkosina@suse.cz> | 2016-04-15 11:31:51 +0200 |
---|---|---|
committer | Jiri Kosina <jkosina@suse.cz> | 2016-04-15 11:42:51 +0200 |
commit | 4d4fb97a62105c07dcccd350c391a65f576726c4 (patch) | |
tree | 36f5ba480d7ea790b8cedf7e49bebab781659f73 /kernel/livepatch | |
parent | 61bf12d3304d78ff499245ea995858c3bedb162e (diff) | |
parent | 85baa095497f3e590df9f6c8932121f123efca5c (diff) |
Merge branch 'topic/livepatch' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux into for-4.7/livepatching-ppc64le
Pull livepatching support for ppc64 architecture from Michael Ellerman.
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Diffstat (limited to 'kernel/livepatch')
-rw-r--r-- | kernel/livepatch/core.c | 34 |
1 files changed, 31 insertions, 3 deletions
diff --git a/kernel/livepatch/core.c b/kernel/livepatch/core.c index 28c37fa3d3f9..a19f1954f4ac 100644 --- a/kernel/livepatch/core.c +++ b/kernel/livepatch/core.c @@ -334,6 +334,19 @@ unlock: rcu_read_unlock(); } +/* + * Convert a function address into the appropriate ftrace location. + * + * Usually this is just the address of the function, but on some architectures + * it's more complicated so allow them to provide a custom behaviour. + */ +#ifndef klp_get_ftrace_location +static unsigned long klp_get_ftrace_location(unsigned long faddr) +{ + return faddr; +} +#endif + static void klp_disable_func(struct klp_func *func) { struct klp_ops *ops; @@ -348,8 +361,14 @@ static void klp_disable_func(struct klp_func *func) return; if (list_is_singular(&ops->func_stack)) { + unsigned long ftrace_loc; + + ftrace_loc = klp_get_ftrace_location(func->old_addr); + if (WARN_ON(!ftrace_loc)) + return; + WARN_ON(unregister_ftrace_function(&ops->fops)); - WARN_ON(ftrace_set_filter_ip(&ops->fops, func->old_addr, 1, 0)); + WARN_ON(ftrace_set_filter_ip(&ops->fops, ftrace_loc, 1, 0)); list_del_rcu(&func->stack_node); list_del(&ops->node); @@ -374,6 +393,15 @@ static int klp_enable_func(struct klp_func *func) ops = klp_find_ops(func->old_addr); if (!ops) { + unsigned long ftrace_loc; + + ftrace_loc = klp_get_ftrace_location(func->old_addr); + if (!ftrace_loc) { + pr_err("failed to find location for function '%s'\n", + func->old_name); + return -EINVAL; + } + ops = kzalloc(sizeof(*ops), GFP_KERNEL); if (!ops) return -ENOMEM; @@ -388,7 +416,7 @@ static int klp_enable_func(struct klp_func *func) INIT_LIST_HEAD(&ops->func_stack); list_add_rcu(&func->stack_node, &ops->func_stack); - ret = ftrace_set_filter_ip(&ops->fops, func->old_addr, 0, 0); + ret = ftrace_set_filter_ip(&ops->fops, ftrace_loc, 0, 0); if (ret) { pr_err("failed to set ftrace filter for function '%s' (%d)\n", func->old_name, ret); @@ -399,7 +427,7 @@ static int klp_enable_func(struct klp_func *func) if (ret) { pr_err("failed to register ftrace handler for function '%s' (%d)\n", func->old_name, ret); - ftrace_set_filter_ip(&ops->fops, func->old_addr, 1, 0); + ftrace_set_filter_ip(&ops->fops, ftrace_loc, 1, 0); goto err; } |