From 2ee7c922f20c96dba56fd378a466790d87f42e84 Mon Sep 17 00:00:00 2001 From: Oleg Nesterov Date: Mon, 9 Aug 2010 17:20:30 -0700 Subject: [PATCH] sys_personality: remove the bogus checks in sys_personality()->__set_personality() path Cleanup, no functional changes. - __set_personality() always changes ->exec_domain/personality, the special case when ->exec_domain remains the same buys nothing but complicates the code. Unify both cases to simplify the code. - The -EINVAL check in sys_personality() was never right. If we assume that set_personality() can fail we should check the value it returns instead of verifying that task->personality was actually changed. Remove it. Before the previous patch it was possible to hit this case due to overflow problems, but this -EINVAL just indicated the kernel bug. OTOH, probably it makes sense to change lookup_exec_domain() to return ERR_PTR() instead of default_exec_domain if the search in exec_domains list fails, and report this error to the user-space. But this means another user-space change, and we have in-kernel users which need fixes. For example, PER_OSF4 falls into PER_MASK for unkown reason and nobody cares to register this domain. Signed-off-by: Oleg Nesterov Cc: Wenming Zhang Cc: "H. Peter Anvin" Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/exec_domain.c | 22 +++++----------------- 1 file changed, 5 insertions(+), 17 deletions(-) diff --git a/kernel/exec_domain.c b/kernel/exec_domain.c index dd62f8e714c..0dbeae37422 100644 --- a/kernel/exec_domain.c +++ b/kernel/exec_domain.c @@ -134,23 +134,14 @@ unregister: return 0; } -int -__set_personality(unsigned int personality) +int __set_personality(unsigned int personality) { - struct exec_domain *ep, *oep; - - ep = lookup_exec_domain(personality); - if (ep == current_thread_info()->exec_domain) { - current->personality = personality; - module_put(ep->module); - return 0; - } + struct exec_domain *oep = current_thread_info()->exec_domain; + current_thread_info()->exec_domain = lookup_exec_domain(personality); current->personality = personality; - oep = current_thread_info()->exec_domain; - current_thread_info()->exec_domain = ep; - module_put(oep->module); + return 0; } @@ -192,11 +183,8 @@ SYSCALL_DEFINE1(personality, unsigned int, personality) { unsigned int old = current->personality; - if (personality != 0xffffffff) { + if (personality != 0xffffffff) set_personality(personality); - if (current->personality != personality) - return -EINVAL; - } return old; } -- 2.20.1