The intialization function checks for various failure scenarios, but unfortunately the compiler gets a little confused about the possible combinations, leading to a false-positive build warning when -Wmaybe-uninitialized is set:
arch/x86/events/core.c: In function ‘init_hw_perf_events’: arch/x86/events/core.c:264:3: warning: ‘reg_fail’ may be used uninitialized in this function [-Wmaybe-uninitialized] arch/x86/events/core.c:264:3: warning: ‘val_fail’ may be used uninitialized in this function [-Wmaybe-uninitialized] pr_err(FW_BUG "the BIOS has corrupted hw-PMU resources (MSR %x is %Lx)\n", We can't actually run into this case, so this shuts up the warning by initializing the variables to a known-invalid state. Link: https://patchwork.kernel.org/patch/9392595/ Suggested-by: Peter Zijlstra <pet...@infradead.org> Signed-off-by: Arnd Bergmann <a...@arndb.de> --- v2: replaced original patch that reordered the code instead of adding a fake initialization. --- arch/x86/events/core.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/x86/events/core.c b/arch/x86/events/core.c index ff1ea2fb9705..8e3db8f642a7 100644 --- a/arch/x86/events/core.c +++ b/arch/x86/events/core.c @@ -191,8 +191,8 @@ static void release_pmc_hardware(void) {} static bool check_hw_exists(void) { - u64 val, val_fail, val_new= ~0; - int i, reg, reg_fail, ret = 0; + u64 val, val_fail = -1, val_new= ~0; + int i, reg, reg_fail = -1, ret = 0; int bios_fail = 0; int reg_safe = -1; -- 2.9.0
