4.14-stable review patch. If anyone has any objections, please let me know.
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From: Andrey Ryabinin aryabinin@virtuozzo.com
commit bac7a1fff7926fb9891a18fe33650884b0e13e41 upstream.
Similarly to type mismatch checks, new GCC 8.x and Clang also changed for ABI for returns_nonnull checks. While we can update our code to conform the new ABI it's more reasonable to just remove it. Because it's just dead code, we don't have any single user of returns_nonnull attribute in the whole kernel.
And AFAIU the advantage that this attribute could bring would be mitigated by -fno-delete-null-pointer-checks cflag that we use to build the kernel. So it's unlikely we will have a lot of returns_nonnull attribute in future.
So let's just remove the code, it has no use.
[aryabinin@virtuozzo.com: fix warning] Link: http://lkml.kernel.org/r/20180122165711.11510-1-aryabinin@virtuozzo.com Link: http://lkml.kernel.org/r/20180119152853.16806-2-aryabinin@virtuozzo.com Signed-off-by: Andrey Ryabinin aryabinin@virtuozzo.com Cc: Sodagudi Prasad psodagud@codeaurora.org Signed-off-by: Andrew Morton akpm@linux-foundation.org Signed-off-by: Linus Torvalds torvalds@linux-foundation.org Cc: Lukas Bulwahn lukas.bulwahn@gmail.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- lib/ubsan.c | 24 ------------------------ lib/ubsan.h | 5 ----- scripts/Makefile.ubsan | 1 - 3 files changed, 30 deletions(-)
--- a/lib/ubsan.c +++ b/lib/ubsan.c @@ -143,11 +143,6 @@ static void val_to_string(char *str, siz } }
-static bool location_is_valid(struct source_location *loc) -{ - return loc->file_name != NULL; -} - static DEFINE_SPINLOCK(report_lock);
static void ubsan_prologue(struct source_location *location, @@ -354,25 +349,6 @@ void __ubsan_handle_type_mismatch_v1(str } EXPORT_SYMBOL(__ubsan_handle_type_mismatch_v1);
-void __ubsan_handle_nonnull_return(struct nonnull_return_data *data) -{ - unsigned long flags; - - if (suppress_report(&data->location)) - return; - - ubsan_prologue(&data->location, &flags); - - pr_err("null pointer returned from function declared to never return null\n"); - - if (location_is_valid(&data->attr_location)) - print_source_location("returns_nonnull attribute specified in", - &data->attr_location); - - ubsan_epilogue(&flags); -} -EXPORT_SYMBOL(__ubsan_handle_nonnull_return); - void __ubsan_handle_vla_bound_not_positive(struct vla_bound_data *data, void *bound) { --- a/lib/ubsan.h +++ b/lib/ubsan.h @@ -57,11 +57,6 @@ struct nonnull_arg_data { int arg_index; };
-struct nonnull_return_data { - struct source_location location; - struct source_location attr_location; -}; - struct vla_bound_data { struct source_location location; struct type_descriptor *type; --- a/scripts/Makefile.ubsan +++ b/scripts/Makefile.ubsan @@ -7,7 +7,6 @@ ifdef CONFIG_UBSAN CFLAGS_UBSAN += $(call cc-option, -fsanitize=signed-integer-overflow) CFLAGS_UBSAN += $(call cc-option, -fsanitize=bounds) CFLAGS_UBSAN += $(call cc-option, -fsanitize=object-size) - CFLAGS_UBSAN += $(call cc-option, -fsanitize=returns-nonnull-attribute) CFLAGS_UBSAN += $(call cc-option, -fsanitize=bool) CFLAGS_UBSAN += $(call cc-option, -fsanitize=enum)