From d5dc3a927ae7e64bc998d9aa29020426b4e97f8a Mon Sep 17 00:00:00 2001 From: Richard Henderson Date: Mon, 8 Apr 2024 16:07:05 -1000 Subject: [PATCH] target/i386: Convert do_xrstor to X86Access Reviewed-by: Paolo Bonzini Signed-off-by: Richard Henderson --- target/i386/tcg/fpu_helper.c | 106 ++++++++++++++++++++++++++----------------- 1 file changed, 64 insertions(+), 42 deletions(-) diff --git a/target/i386/tcg/fpu_helper.c b/target/i386/tcg/fpu_helper.c index f5748b72b8..1ac61c5d7d 100644 --- a/target/i386/tcg/fpu_helper.c +++ b/target/i386/tcg/fpu_helper.c @@ -2903,51 +2903,38 @@ void helper_fxrstor(CPUX86State *env, target_ulong ptr) do_fxrstor(&ac, ptr); } -static void do_xrstor(CPUX86State *env, target_ulong ptr, uint64_t rfbm, uintptr_t ra) +static bool valid_xrstor_header(X86Access *ac, uint64_t *pxsbv, + target_ulong ptr) { uint64_t xstate_bv, xcomp_bv, reserve0; - X86Access ac; - unsigned size, size_ext; - - rfbm &= env->xcr0; - - size = sizeof(X86LegacyXSaveArea) + sizeof(X86XSaveHeader); - access_prepare(&ac, env, ptr, size, MMU_DATA_LOAD, ra); - xstate_bv = access_ldq(&ac, ptr + XO(header.xstate_bv)); + xstate_bv = access_ldq(ac, ptr + XO(header.xstate_bv)); + xcomp_bv = access_ldq(ac, ptr + XO(header.xcomp_bv)); + reserve0 = access_ldq(ac, ptr + XO(header.reserve0)); + *pxsbv = xstate_bv; - if ((int64_t)xstate_bv < 0) { - /* FIXME: Compact form. */ - raise_exception_ra(env, EXCP0D_GPF, ra); + /* + * XCOMP_BV bit 63 indicates compact form, which we do not support, + * and thus must raise #GP. That leaves us in standard form. + * In standard form, bytes 23:8 must be zero -- which is both + * XCOMP_BV and the following 64-bit field. + */ + if (xcomp_bv || reserve0) { + return false; } - /* Standard form. */ - /* The XSTATE_BV field must not set bits not present in XCR0. */ - if (xstate_bv & ~env->xcr0) { - raise_exception_ra(env, EXCP0D_GPF, ra); - } - - /* The XCOMP_BV field must be zero. Note that, as of the April 2016 - revision, the description of the XSAVE Header (Vol 1, Sec 13.4.2) - describes only XCOMP_BV, but the description of the standard form - of XRSTOR (Vol 1, Sec 13.8.1) checks bytes 23:8 for zero, which - includes the next 64-bit field. */ - xcomp_bv = access_ldq(&ac, ptr + XO(header.xcomp_bv)); - reserve0 = access_ldq(&ac, ptr + XO(header.reserve0)); - if (xcomp_bv || reserve0) { - raise_exception_ra(env, EXCP0D_GPF, ra); - } + return (xstate_bv & ~ac->env->xcr0) == 0; +} - size_ext = xsave_area_size(rfbm & xstate_bv, false); - if (size < size_ext) { - /* TODO: See if existing page probe has covered extra size. */ - access_prepare(&ac, env, ptr, size_ext, MMU_DATA_LOAD, ra); - } +static void do_xrstor(X86Access *ac, target_ulong ptr, + uint64_t rfbm, uint64_t xstate_bv) +{ + CPUX86State *env = ac->env; if (rfbm & XSTATE_FP_MASK) { if (xstate_bv & XSTATE_FP_MASK) { - do_xrstor_fpu(&ac, ptr); + do_xrstor_fpu(ac, ptr); } else { do_fninit(env); memset(env->fpregs, 0, sizeof(env->fpregs)); @@ -2956,23 +2943,23 @@ static void do_xrstor(CPUX86State *env, target_ulong ptr, uint64_t rfbm, uintptr if (rfbm & XSTATE_SSE_MASK) { /* Note that the standard form of XRSTOR loads MXCSR from memory whether or not the XSTATE_BV bit is set. */ - do_xrstor_mxcsr(&ac, ptr); + do_xrstor_mxcsr(ac, ptr); if (xstate_bv & XSTATE_SSE_MASK) { - do_xrstor_sse(&ac, ptr); + do_xrstor_sse(ac, ptr); } else { do_clear_sse(env); } } if (rfbm & XSTATE_YMM_MASK) { if (xstate_bv & XSTATE_YMM_MASK) { - do_xrstor_ymmh(&ac, ptr + XO(avx_state)); + do_xrstor_ymmh(ac, ptr + XO(avx_state)); } else { do_clear_ymmh(env); } } if (rfbm & XSTATE_BNDREGS_MASK) { if (xstate_bv & XSTATE_BNDREGS_MASK) { - do_xrstor_bndregs(&ac, ptr + XO(bndreg_state)); + do_xrstor_bndregs(ac, ptr + XO(bndreg_state)); env->hflags |= HF_MPX_IU_MASK; } else { memset(env->bnd_regs, 0, sizeof(env->bnd_regs)); @@ -2981,7 +2968,7 @@ static void do_xrstor(CPUX86State *env, target_ulong ptr, uint64_t rfbm, uintptr } if (rfbm & XSTATE_BNDCSR_MASK) { if (xstate_bv & XSTATE_BNDCSR_MASK) { - do_xrstor_bndcsr(&ac, ptr + XO(bndcsr_state)); + do_xrstor_bndcsr(ac, ptr + XO(bndcsr_state)); } else { memset(&env->bndcs_regs, 0, sizeof(env->bndcs_regs)); } @@ -2990,7 +2977,7 @@ static void do_xrstor(CPUX86State *env, target_ulong ptr, uint64_t rfbm, uintptr if (rfbm & XSTATE_PKRU_MASK) { uint64_t old_pkru = env->pkru; if (xstate_bv & XSTATE_PKRU_MASK) { - do_xrstor_pkru(&ac, ptr + XO(pkru_state)); + do_xrstor_pkru(ac, ptr + XO(pkru_state)); } else { env->pkru = 0; } @@ -3006,9 +2993,27 @@ static void do_xrstor(CPUX86State *env, target_ulong ptr, uint64_t rfbm, uintptr void helper_xrstor(CPUX86State *env, target_ulong ptr, uint64_t rfbm) { uintptr_t ra = GETPC(); + X86Access ac; + uint64_t xstate_bv; + unsigned size, size_ext; do_xsave_chk(env, ptr, ra); - do_xrstor(env, ptr, rfbm, ra); + + /* Begin with just the minimum size to validate the header. */ + size = sizeof(X86LegacyXSaveArea) + sizeof(X86XSaveHeader); + access_prepare(&ac, env, ptr, size, MMU_DATA_LOAD, ra); + if (!valid_xrstor_header(&ac, &xstate_bv, ptr)) { + raise_exception_ra(env, EXCP0D_GPF, ra); + } + + rfbm &= env->xcr0; + size_ext = xsave_area_size(rfbm & xstate_bv, false); + if (size < size_ext) { + /* TODO: See if existing page probe has covered extra size. */ + access_prepare(&ac, env, ptr, size_ext, MMU_DATA_LOAD, ra); + } + + do_xrstor(&ac, ptr, rfbm, xstate_bv); } #if defined(CONFIG_USER_ONLY) @@ -3066,7 +3071,24 @@ void cpu_x86_xsave(CPUX86State *env, target_ulong ptr, uint64_t rfbm) void cpu_x86_xrstor(CPUX86State *env, target_ulong ptr, uint64_t rfbm) { - do_xrstor(env, ptr, rfbm, 0); + X86Access ac; + uint64_t xstate_bv; + unsigned size; + + /* + * Since this is only called from user-level signal handling, + * we should have done the job correctly there. + */ + assert((rfbm & ~env->xcr0) == 0); + size = xsave_area_size(rfbm, false); + access_prepare(&ac, env, ptr, size, MMU_DATA_LOAD, 0); + + if (!valid_xrstor_header(&ac, &xstate_bv, ptr)) { + /* TODO: Report failure to caller. */ + xstate_bv &= env->xcr0; + } + + do_xrstor(&ac, ptr, rfbm, xstate_bv); } #endif -- 2.11.4.GIT