From 5aa7eea9316ceb4b57175ce04b39e498105b7e92 Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Tue, 28 Sep 2021 11:34:33 +0200 Subject: [PATCH] printk: avoid -Wsometimes-uninitialized warning clang notices that the pi_get_entry() function would use uninitialized data if it was called with a non-NULL module pointer on a kernel that does not support modules: kernel/printk/index.c:32:6: error: variable 'nr_entries' is used uninitialized whenever 'if' condition is false [-Werror,-Wsometimes-uninitialized] if (!mod) { ^~~~ kernel/printk/index.c:38:13: note: uninitialized use occurs here if (pos >= nr_entries) ^~~~~~~~~~ kernel/printk/index.c:32:2: note: remove the 'if' if its condition is always true if (!mod) { Rework the condition to make it clear to the compiler that we are always in the second case. Unfortunately the #ifdef is still required as the definition of 'struct module' is hidden when modules are disabled. Fixes: 337015573718 ("printk: Userspace format indexing support") Suggested-by: Steven Rostedt Signed-off-by: Arnd Bergmann Signed-off-by: Petr Mladek Link: https://lore.kernel.org/r/20210928093456.2438109-1-arnd@kernel.org --- kernel/printk/index.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/kernel/printk/index.c b/kernel/printk/index.c index d3709408debe..c85be186a783 100644 --- a/kernel/printk/index.c +++ b/kernel/printk/index.c @@ -26,10 +26,9 @@ static struct pi_entry *pi_get_entry(const struct module *mod, loff_t pos) if (mod) { entries = mod->printk_index_start; nr_entries = mod->printk_index_size; - } + } else #endif - - if (!mod) { + { /* vmlinux, comes from linker symbols */ entries = __start_printk_index; nr_entries = __stop_printk_index - __start_printk_index;