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authorAhmad Fatoum <a.fatoum@pengutronix.de>2020-10-15 11:00:56 +0200
committerSascha Hauer <s.hauer@pengutronix.de>2020-10-19 09:58:30 +0200
commitb5260d5134fd57b0b07edf2605b33047dc1406e0 (patch)
tree86f63094a380755d5a847cba241447875ec36c34
parentceb5431a2feccc0bbe7e650c90946056513cba88 (diff)
downloadbarebox-b5260d5134fd57b0b07edf2605b33047dc1406e0.tar.gz
barebox-b5260d5134fd57b0b07edf2605b33047dc1406e0.tar.xz
Revert "common: ubsan: ignore shifting one into sign bit"
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 <a.fatoum@pengutronix.de> Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
-rw-r--r--lib/ubsan.c20
1 files changed, 0 insertions, 20 deletions
diff --git a/lib/ubsan.c b/lib/ubsan.c
index 085d470cf..648c7cc48 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);