Date: Tue, 2 Apr 2024 15:18:17 GMT From: Konstantin Belousov <kib@FreeBSD.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-branches@FreeBSD.org Subject: git: b79fb02b32d9 - stable/13 - x86: handle MXCSR from XSAVEOPT when x87 state was optimized Message-ID: <202404021518.432FIH1U057790@gitrepo.freebsd.org>
next in thread | raw e-mail | index | archive | help
The branch stable/13 has been updated by kib: URL: https://cgit.FreeBSD.org/src/commit/?id=b79fb02b32d930b1940ad7a21cb17896c848d432 commit b79fb02b32d930b1940ad7a21cb17896c848d432 Author: Konstantin Belousov <kib@FreeBSD.org> AuthorDate: 2024-03-27 11:01:44 +0000 Commit: Konstantin Belousov <kib@FreeBSD.org> CommitDate: 2024-04-02 15:18:00 +0000 x86: handle MXCSR from XSAVEOPT when x87 state was optimized PR: 275322 (cherry picked from commit 1c091d11261a3c8cc3728b92760e65242c0f5949) --- sys/amd64/amd64/fpu.c | 21 +++++++++++++++++++++ sys/i386/i386/npx.c | 21 +++++++++++++++++++++ 2 files changed, 42 insertions(+) diff --git a/sys/amd64/amd64/fpu.c b/sys/amd64/amd64/fpu.c index 18330cb58d3c..3f06033ae89a 100644 --- a/sys/amd64/amd64/fpu.c +++ b/sys/amd64/amd64/fpu.c @@ -875,7 +875,10 @@ fpugetregs(struct thread *td) struct pcb *pcb; uint64_t *xstate_bv, bit; char *sa; + struct savefpu *s; + uint32_t mxcsr, mxcsr_mask; int max_ext_n, i, owned; + bool do_mxcsr; pcb = td->td_pcb; critical_enter(); @@ -906,10 +909,28 @@ fpugetregs(struct thread *td) bit = 1ULL << i; if ((xsave_mask & bit) == 0 || (*xstate_bv & bit) != 0) continue; + do_mxcsr = false; + if (i == 0 && (*xstate_bv & (XFEATURE_ENABLED_SSE | + XFEATURE_ENABLED_AVX)) != 0) { + /* + * x87 area was not saved by XSAVEOPT, + * but one of XMM or AVX was. Then we need + * to preserve MXCSR from being overwritten + * with the default value. + */ + s = (struct savefpu *)sa; + mxcsr = s->sv_env.en_mxcsr; + mxcsr_mask = s->sv_env.en_mxcsr_mask; + do_mxcsr = true; + } bcopy((char *)fpu_initialstate + xsave_area_desc[i].offset, sa + xsave_area_desc[i].offset, xsave_area_desc[i].size); + if (do_mxcsr) { + s->sv_env.en_mxcsr = mxcsr; + s->sv_env.en_mxcsr_mask = mxcsr_mask; + } *xstate_bv |= bit; } } diff --git a/sys/i386/i386/npx.c b/sys/i386/i386/npx.c index e7e8fc01fa6b..09abf7c17438 100644 --- a/sys/i386/i386/npx.c +++ b/sys/i386/i386/npx.c @@ -1001,8 +1001,11 @@ npxgetregs(struct thread *td) struct pcb *pcb; uint64_t *xstate_bv, bit; char *sa; + union savefpu *s; + uint32_t mxcsr, mxcsr_mask; int max_ext_n, i; int owned; + bool do_mxcsr; if (!hw_float) return (_MC_FPOWNED_NONE); @@ -1045,10 +1048,28 @@ npxgetregs(struct thread *td) bit = 1ULL << i; if ((xsave_mask & bit) == 0 || (*xstate_bv & bit) != 0) continue; + do_mxcsr = false; + if (i == 0 && (*xstate_bv & (XFEATURE_ENABLED_SSE | + XFEATURE_ENABLED_AVX)) != 0) { + /* + * x87 area was not saved by XSAVEOPT, + * but one of XMM or AVX was. Then we need + * to preserve MXCSR from being overwritten + * with the default value. + */ + s = (union savefpu *)sa; + mxcsr = s->sv_xmm.sv_env.en_mxcsr; + mxcsr_mask = s->sv_xmm.sv_env.en_mxcsr_mask; + do_mxcsr = true; + } bcopy((char *)npx_initialstate + xsave_area_desc[i].offset, sa + xsave_area_desc[i].offset, xsave_area_desc[i].size); + if (do_mxcsr) { + s->sv_xmm.sv_env.en_mxcsr = mxcsr; + s->sv_xmm.sv_env.en_mxcsr_mask = mxcsr_mask; + } *xstate_bv |= bit; } }
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?202404021518.432FIH1U057790>