From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from metis.ext.pengutronix.de ([2001:67c:670:201:290:27ff:fe1d:cc33]) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1kSz8A-0002OY-BJ for barebox@lists.infradead.org; Thu, 15 Oct 2020 09:01:07 +0000 From: Ahmad Fatoum Date: Thu, 15 Oct 2020 11:00:56 +0200 Message-Id: <20201015090055.31130-3-a.fatoum@pengutronix.de> In-Reply-To: <20201015090055.31130-1-a.fatoum@pengutronix.de> References: <20201015090055.31130-1-a.fatoum@pengutronix.de> MIME-Version: 1.0 List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "barebox" Errors-To: barebox-bounces+u.kleine-koenig=pengutronix.de@lists.infradead.org Subject: [PATCH 3/3] Revert "common: ubsan: ignore shifting one into sign bit" To: barebox@lists.infradead.org Cc: Ahmad Fatoum With the previous commit, we now explicitly tell GCC not to optimize constructs like (1 << 31) under assumption that they are undefined anyway. GCC >= 8.0 -fsanitize=undefined should now not warn any longer about (1 << 31) instances, so remove our work around. This reverts commit 55397b9ebe3a21a3aeb6a98131c0991bff0f7123. Signed-off-by: Ahmad Fatoum --- lib/ubsan.c | 20 -------------------- 1 file changed, 20 deletions(-) diff --git a/lib/ubsan.c b/lib/ubsan.c index 085d470cf784..648c7cc48a60 100644 --- a/lib/ubsan.c +++ b/lib/ubsan.c @@ -382,26 +382,6 @@ void __ubsan_handle_shift_out_of_bounds(struct shift_out_of_bounds_data *data, if (suppress_report(&data->location)) return; - /* This handler would be called for code shifting a one into the - * sign bit like (1 << 31), which is all too common in barebox. - * It's technically UB, but it's so prevalent that it's highly - * unlikely to be treated by a compiler as anything else than the - * standard-compliant (1U << 31). Thus check for this case here - * and ignore it selectively - */ - if (type_is_signed(lhs_type)) { - s_max lhs_int, rhs_int; - - lhs_int = get_signed_val(lhs_type, lhs); - rhs_int = get_signed_val(rhs_type, rhs); - - if (fls(lhs_int) + rhs_int == type_bit_width(lhs_type)) { - pr_debug("signed left shift of %lld by %lld ignored.\n", - (s64)lhs_int, (s64)rhs_int); - return; - } - } - ubsan_prologue(&data->location, &flags); val_to_string(rhs_str, sizeof(rhs_str), rhs_type, rhs); -- 2.28.0 _______________________________________________ barebox mailing list barebox@lists.infradead.org http://lists.infradead.org/mailman/listinfo/barebox