File vbox-upd07-fix-fpu-crpt.diff of Package virtualbox52
https://www.virtualbox.org/ticket/20914
https://www.spinics.net/lists/kernel/msg4373008.html
--- a/src/VBox/Runtime/r0drv/linux/the-linux-kernel.h 2023-03-07 22:13:29.000000000 +0300
+++ b/src/VBox/Runtime/r0drv/linux/the-linux-kernel.h 2023-03-07 22:16:48.528684922 +0300
@@ -166,6 +166,11 @@
# include <asm/tlbflush.h>
#endif
+/* for kernel_fpu_begin / kernel_fpu_end() */
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(4,2,0)
+# include <asm/fpu/api.h>
+#endif
+
/* for set_pages_x() */
#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 12, 0)
# include <asm/set_memory.h>
--- a/src/VBox/HostDrivers/Support/linux/SUPDrv-linux.c 2023-03-07 22:13:29.000000000 +0300
+++ b/src/VBox/HostDrivers/Support/linux/SUPDrv-linux.c 2023-03-07 22:21:18.332683893 +0300
@@ -40,6 +40,7 @@
#include <iprt/semaphore.h>
#include <iprt/initterm.h>
#include <iprt/process.h>
+#include <iprt/thread.h>
#include <VBox/err.h>
#include <iprt/mem.h>
#include <VBox/log.h>
@@ -1437,6 +1438,61 @@
}
+SUPR0DECL(bool) SUPR0FpuBegin(bool fCtxHook)
+{
+ RT_NOREF(fCtxHook);
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(4,19,0) /* Going back to 4.19.0 for better coverage, we
+ probably only need 5.17.7+ in the end. */
+ /*
+ * HACK ALERT!
+ *
+ * We'd like to use the old __kernel_fpu_begin() API which was removed in
+ * early 2019, because we typically run with preemption enabled and have an
+ * preemption hook installed which will call kernel_fpu_end() in case we're
+ * scheduled out after getting in here. The preemption hook is almost
+ * useless if we run with preemption disabled.
+ *
+ * For the case where the kernel does not have preemption hooks, we get here
+ * with preemption already disabled and one more count doesn't make any
+ * difference.
+ *
+ * So, after the kernel_fpu_begin() call we undo the implicit preempt_disable()
+ * call it does, so the preemption hook can do its work and the VBox user has
+ * a more responsive system.
+ *
+ * See @bugref{10209#c12} and onwards for more details.
+ */
+ Assert(fCtxHook || !RTThreadPreemptIsEnabled(NIL_RTTHREAD));
+ kernel_fpu_begin();
+# if 0 /* Always do it for now for better test coverage. */
+ if (fCtxHook)
+# endif
+ preempt_enable();
+ return false; /** @todo Not sure if we have license to use any extended state, or
+ * if we're limited to the SSE & x87 FPU. If it's the former,
+ * we should return @a true and the caller can skip
+ * saving+restoring the host state and save some time. */
+#else
+ return false;
+#endif
+}
+
+
+SUPR0DECL(void) SUPR0FpuEnd(bool fCtxHook)
+{
+ RT_NOREF(fCtxHook);
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(4,19,0)
+ /* HACK ALERT! See SUPR0FpuBegin for an explanation of this. */
+ Assert(!RTThreadPreemptIsEnabled(NIL_RTTHREAD));
+# if 0 /* Always do it for now for better test coverage. */
+ if (fCtxHook)
+# endif
+ preempt_disable();
+ kernel_fpu_end();
+#endif
+}
+
+
int VBOXCALL supdrvOSGetCurrentGdtRw(RTHCUINTPTR *pGdtRw)
{
#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 12, 0)
--- a/include/VBox/sup.h 2020-07-09 19:49:50.000000000 +0300
+++ b/include/VBox/sup.h 2023-03-07 22:24:34.948683142 +0300
@@ -1951,6 +1951,26 @@
*/
SUPR0DECL(uint32_t) SUPR0GetKernelFeatures(void);
+/**
+ * Notification from R0 VMM prior to loading the guest-FPU register state.
+ *
+ * @returns Whether the host-FPU register state has been saved by the host kernel.
+ * @param fCtxHook Whether thread-context hooks are enabled.
+ *
+ * @remarks Called with preemption disabled.
+ */
+SUPR0DECL(bool) SUPR0FpuBegin(bool fCtxHook);
+
+/**
+ * Notification from R0 VMM after saving the guest-FPU register state (and
+ * potentially restoring the host-FPU register state) in ring-0.
+ *
+ * @param fCtxHook Whether thread-context hooks are enabled.
+ *
+ * @remarks Called with preemption disabled.
+ */
+SUPR0DECL(void) SUPR0FpuEnd(bool fCtxHook);
+
/** @name Absolute symbols
* Take the address of these, don't try call them.
--- a/src/VBox/HostDrivers/Support/SUPDrv.cpp 2023-03-07 22:13:29.000000000 +0300
+++ b/src/VBox/HostDrivers/Support/SUPDrv.cpp 2023-03-07 22:34:59.768680757 +0300
@@ -75,6 +75,19 @@
# define VBOXDRV_IOCTL_RETURN(pvSession, uIOCtl, pvReqHdr, rcRet, rcReq) do { } while (0)
#endif
+#if defined(RT_OS_LINUX) && !defined(__NO_FORTIFY) && defined(__OPTIMIZE__) && defined(CONFIG_FORTIFY_SOURCE)
+/* In Linux 5.18-rc1, memcpy became a wrapper which does fortify checks
+ * before triggering __underlying_memcpy() call. We do not pass these checks here,
+ * so bypass them for now. */
+# if LINUX_VERSION_CODE >= KERNEL_VERSION(5,18,0)
+# define SUPDRV_MEMCPY __underlying_memcpy
+# else
+# define SUPDRV_MEMCPY memcpy
+# endif
+#else
+# define SUPDRV_MEMCPY memcpy
+#endif
+
/*
* Logging assignments:
* Log - useful stuff, like failures.
@@ -196,6 +209,8 @@
{ "SUPR0ContFree", (void *)(uintptr_t)SUPR0ContFree },
{ "SUPR0ChangeCR4", (void *)(uintptr_t)SUPR0ChangeCR4 },
{ "SUPR0EnableVTx", (void *)(uintptr_t)SUPR0EnableVTx },
+ { "SUPR0FpuBegin", (void *)(uintptr_t)SUPR0FpuBegin },
+ { "SUPR0FpuEnd", (void *)(uintptr_t)SUPR0FpuEnd },
{ "SUPR0SuspendVTxOnCpu", (void *)(uintptr_t)SUPR0SuspendVTxOnCpu },
{ "SUPR0ResumeVTxOnCpu", (void *)(uintptr_t)SUPR0ResumeVTxOnCpu },
{ "SUPR0GetCurrentGdtRw", (void *)(uintptr_t)SUPR0GetCurrentGdtRw },
@@ -1663,7 +1678,7 @@
/* execute */
pReq->u.Out.cFunctions = RT_ELEMENTS(g_aFunctions);
- memcpy(&pReq->u.Out.aFunctions[0], g_aFunctions, sizeof(g_aFunctions));
+ SUPDRV_MEMCPY(&pReq->u.Out.aFunctions[0], g_aFunctions, sizeof(g_aFunctions));
pReq->Hdr.rc = VINF_SUCCESS;
return 0;
}
--- a/src/VBox/VMM/VMMR0/CPUMR0.cpp 2020-07-09 19:57:54.000000000 +0300
+++ b/src/VBox/VMM/VMMR0/CPUMR0.cpp 2023-03-07 22:47:27.996677901 +0300
@@ -437,6 +437,11 @@
Assert(!(pVCpu->cpum.s.fUseFlags & CPUM_USED_FPU_GUEST));
Assert(!(pVCpu->cpum.s.fUseFlags & CPUM_SYNC_FPU_STATE));
+ /* Notify the support driver prior to loading the guest-FPU register state. */
+ SUPR0FpuBegin(VMMR0ThreadCtxHookIsEnabled(pVCpu));
+ /** @todo use return value? Currently skipping that to be on the safe side
+ * wrt. extended state (linux). */
+
#if HC_ARCH_BITS == 32 && defined(VBOX_WITH_64_BITS_GUESTS)
if (CPUMIsGuestInLongModeEx(&pVCpu->cpum.s.Guest))
{
@@ -535,6 +540,9 @@
cpumR0SaveGuestRestoreHostFPUState(&pVCpu->cpum.s);
pVCpu->cpum.s.fUseFlags &= ~CPUM_USED_MANUAL_XMM_RESTORE;
}
+
+ /* Notify the support driver after loading the host-FPU register state. */
+ SUPR0FpuEnd(VMMR0ThreadCtxHookIsEnabled(pVCpu));
}
}
else
