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R. Silva" To: Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , "H. Peter Anvin" Cc: x86@kernel.org, linux-kernel@vger.kernel.org, "Gustavo A. R. Silva" , linux-hardening@vger.kernel.org Subject: [PATCH][next] x86/fpu: Replace zero-length array with flexible-array member Message-ID: MIME-Version: 1.0 Content-Disposition: inline X-Spam-Status: No, score=-7.1 required=5.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_HI, SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org X-getmail-retrieved-from-mailbox: =?utf-8?q?INBOX?= X-GMAIL-THRID: =?utf-8?q?1754597901743746639?= X-GMAIL-MSGID: =?utf-8?q?1754597901743746639?= Zero-length arrays are deprecated[1] and we are moving towards adopting C99 flexible-array members instead. So, replace zero-length array declaration in struct xregs_state with flex-array member. This helps with the ongoing efforts to tighten the FORTIFY_SOURCE routines on memcpy() and help us make progress towards globally enabling -fstrict-flex-arrays=3 [2]. Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#zero-length-and-one-element-arrays [1] Link: https://gcc.gnu.org/pipermail/gcc-patches/2022-October/602902.html [2] Link: https://github.com/KSPP/linux/issues/78 Signed-off-by: Gustavo A. R. Silva Reviewed-by: Kees Cook --- arch/x86/include/asm/fpu/types.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/include/asm/fpu/types.h b/arch/x86/include/asm/fpu/types.h index eb7cd1139d97..7f6d858ff47a 100644 --- a/arch/x86/include/asm/fpu/types.h +++ b/arch/x86/include/asm/fpu/types.h @@ -321,7 +321,7 @@ struct xstate_header { struct xregs_state { struct fxregs_state i387; struct xstate_header header; - u8 extended_state_area[0]; + u8 extended_state_area[]; } __attribute__ ((packed, aligned (64))); /*