From bde8adb808eeffb02fdcbd3425f09f1645bdcf4a Mon Sep 17 00:00:00 2001 From: Peter Maydell Date: Tue, 23 Jul 2024 17:25:25 +0100 Subject: [PATCH] target/i386: Remove dead assignment to ss in do_interrupt64() MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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 Message-id: 20240723162525.1585743-1-peter.maydell@linaro.org --- 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 aac092a356..bab552cd53 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;