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authorKonstantin Belousov <kib@FreeBSD.org>2026-07-30 03:57:34 +0000
committerKonstantin Belousov <kib@FreeBSD.org>2026-08-05 06:23:16 +0000
commit2f9a4885ec995e8ea53b42a820fbd9c337a2a907 (patch)
treeb675fdbc48fcf0d764fcc594d5818d9cb5f21dcc
parent838878fc632e8defadd45eef33fafed9bf598e13 (diff)
amd64: do not allow to set reserved bits in MXCSR for ptrace(PT_SETFPREGS)
(cherry picked from commit cef05c5a62ba63eda222eed083972bfaa1449ac2)
-rw-r--r--sys/amd64/amd64/exec_machdep.c17
1 files changed, 12 insertions, 5 deletions
diff --git a/sys/amd64/amd64/exec_machdep.c b/sys/amd64/amd64/exec_machdep.c
index b9c69b7d5a2f..0158afda247f 100644
--- a/sys/amd64/amd64/exec_machdep.c
+++ b/sys/amd64/amd64/exec_machdep.c
@@ -533,13 +533,16 @@ fill_fpregs_xmm(struct savefpu *sv_xmm, struct fpreg *fpregs)
}
/* internalize from fpregs into sv_xmm */
-static void
+static int
set_fpregs_xmm(struct fpreg *fpregs, struct savefpu *sv_xmm)
{
struct envxmm *penv_xmm = &sv_xmm->sv_env;
struct envxmm *penv_fpreg = (struct envxmm *)&fpregs->fpr_env;
int i;
+ if ((penv_fpreg->en_mxcsr & ~cpu_mxcsr_mask) != 0)
+ return (EINVAL);
+
/* fpregs -> pcb */
/* FPU control/status */
penv_xmm->en_cw = penv_fpreg->en_cw;
@@ -549,7 +552,7 @@ set_fpregs_xmm(struct fpreg *fpregs, struct savefpu *sv_xmm)
penv_xmm->en_rip = penv_fpreg->en_rip;
penv_xmm->en_rdp = penv_fpreg->en_rdp;
penv_xmm->en_mxcsr = penv_fpreg->en_mxcsr;
- penv_xmm->en_mxcsr_mask = penv_fpreg->en_mxcsr_mask & cpu_mxcsr_mask;
+ penv_xmm->en_mxcsr_mask = penv_fpreg->en_mxcsr_mask;
/* FPU registers */
for (i = 0; i < 8; ++i)
@@ -558,6 +561,8 @@ set_fpregs_xmm(struct fpreg *fpregs, struct savefpu *sv_xmm)
/* SSE registers */
for (i = 0; i < 16; ++i)
bcopy(fpregs->fpr_xacc[i], sv_xmm->sv_xmm[i].xmm_bytes, 16);
+
+ return (0);
}
/* externalize from td->pcb */
@@ -577,12 +582,14 @@ fill_fpregs(struct thread *td, struct fpreg *fpregs)
int
set_fpregs(struct thread *td, struct fpreg *fpregs)
{
+ int error;
critical_enter();
- set_fpregs_xmm(fpregs, get_pcb_user_save_td(td));
- fpuuserinited(td);
+ error = set_fpregs_xmm(fpregs, get_pcb_user_save_td(td));
+ if (error == 0)
+ fpuuserinited(td);
critical_exit();
- return (0);
+ return (error);
}
/*