From cd32e2dcc9de6c27ecbbfc0e2079fb64b42bad5f Mon Sep 17 00:00:00 2001 From: Anton Blanchard Date: Tue, 11 Nov 2014 09:12:28 +1100 Subject: [PATCH] powerpc: Fix bad NULL pointer check in udbg_uart_getc_poll() We have some code in udbg_uart_getc_poll() that tries to protect against a NULL udbg_uart_in, but gets it all wrong. Found with the LLVM static analyzer (scan-build). Fixes: 309257484cc1 ("powerpc: Cleanup udbg_16550 and add support for LPC PIO-only UARTs") Signed-off-by: Anton Blanchard [mpe: Add some newlines for readability while we're here] Signed-off-by: Michael Ellerman --- arch/powerpc/kernel/udbg_16550.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/arch/powerpc/kernel/udbg_16550.c b/arch/powerpc/kernel/udbg_16550.c index 6e7c4923b5ea..411116c38da4 100644 --- a/arch/powerpc/kernel/udbg_16550.c +++ b/arch/powerpc/kernel/udbg_16550.c @@ -69,8 +69,12 @@ static void udbg_uart_putc(char c) static int udbg_uart_getc_poll(void) { - if (!udbg_uart_in || !(udbg_uart_in(UART_LSR) & LSR_DR)) + if (!udbg_uart_in) + return -1; + + if (!(udbg_uart_in(UART_LSR) & LSR_DR)) return udbg_uart_in(UART_RBR); + return -1; }