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[2001:8b0:1d0::2]) by smtp.gmail.com with ESMTPSA id 5b1f17b1804b1-427d68f789csm180936945e9.6.2024.07.23.09.25.25 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 23 Jul 2024 09:25:26 -0700 (PDT) From: Peter Maydell To: qemu-devel@nongnu.org Cc: Paolo Bonzini , Richard Henderson , Eduardo Habkost Subject: [PATCH] target/i386: Remove dead assignment to ss in do_interrupt64() Date: Tue, 23 Jul 2024 17:25:25 +0100 Message-Id: <20240723162525.1585743-1-peter.maydell@linaro.org> X-Mailer: git-send-email 2.34.1 MIME-Version: 1.0 Received-SPF: pass client-ip=2a00:1450:4864:20::429; envelope-from=peter.maydell@linaro.org; helo=mail-wr1-x429.google.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Coverity points out that in do_interrupt64() in the "to inner privilege" codepath we set "ss = 0", but because we also set "new_stack = 1" there, later in the function we will always override that value of ss with "ss = 0 | dpl". Remove the unnecessary initialization of ss, which allows us to reduce the scope of the variable to only where it is used. Borrow a comment from helper_lcall_protected() that explains what "0 | dpl" means here. Resolves: Coverity CID 1527395 Signed-off-by: Peter Maydell Reviewed-by: Richard Henderson Reviewed-by: Philippe Mathieu-Daudé --- target/i386/tcg/seg_helper.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/target/i386/tcg/seg_helper.c b/target/i386/tcg/seg_helper.c index aac092a356b..bab552cd535 100644 --- a/target/i386/tcg/seg_helper.c +++ b/target/i386/tcg/seg_helper.c @@ -926,7 +926,7 @@ static void do_interrupt64(CPUX86State *env, int intno, int is_int, target_ulong ptr; int type, dpl, selector, cpl, ist; int has_error_code, new_stack; - uint32_t e1, e2, e3, ss, eflags; + uint32_t e1, e2, e3, eflags; target_ulong old_eip, offset; bool set_rf; StackAccess sa; @@ -1007,7 +1007,6 @@ static void do_interrupt64(CPUX86State *env, int intno, int is_int, /* to inner privilege */ new_stack = 1; sa.sp = get_rsp_from_tss(env, ist != 0 ? ist + 3 : dpl); - ss = 0; } else { /* to same privilege */ if (env->eflags & VM_MASK) { @@ -1040,7 +1039,7 @@ static void do_interrupt64(CPUX86State *env, int intno, int is_int, env->eflags &= ~(TF_MASK | VM_MASK | RF_MASK | NT_MASK); if (new_stack) { - ss = 0 | dpl; + uint32_t ss = 0 | dpl; /* SS = NULL selector with RPL = new CPL */ cpu_x86_load_seg_cache(env, R_SS, ss, 0, 0, dpl << DESC_DPL_SHIFT); } env->regs[R_ESP] = sa.sp;