vmmon: quick workaround for objtool warnings

As discussed in

  https://bugzilla.suse.com/show_bug.cgi?id=1059674

the reason for multiple objtool warnings is the fact that vmmon module
defines its own Panic() function which never returns. While it is marked as
such which is used by the compiler for optimization, there is no way to
find this from object file.

While this seems innocuous, it might result in problems with unwinder
later. The quickest way around is to replace vmmon's own Panic() with
standard kernel panic() until a cleaner solution is found.

vmmon-only/Makefile

@@ -107,7 +107,7 @@ prebuild:: ;
 postbuild:: ;
 
 $(DRIVER_KO): prebuild
-	$(MAKE) -C $(BUILD_DIR) M=$$PWD SRCROOT=$$PWD/$(SRCROOT) \
+	$(MAKE) -C $(BUILD_DIR) SUBDIRS=$$PWD SRCROOT=$$PWD/$(SRCROOT) \
 	  MODULEBUILDDIR=$(MODULEBUILDDIR) modules
 	$(MAKE) -C $$PWD SRCROOT=$$PWD/$(SRCROOT) \
 	  MODULEBUILDDIR=$(MODULEBUILDDIR) postbuild

vmmon-only/Makefile.kernel

@@ -31,7 +31,7 @@ $(DRIVER)-y := $(subst $(SRCROOT)/, , $(patsubst %.c, %.o, \
 		$(SRCROOT)/bootstrap/*.c)))
 
 clean:
-	rm -rf $(wildcard $(DRIVER).mod.c $(DRIVER).ko .tmp_versions .cache.mk \
+	rm -rf $(wildcard $(DRIVER).mod.c $(DRIVER).ko .tmp_versions \
 		Module.symvers Modules.symvers Module.markers modules.order \
 		$(foreach dir,linux/ common/ vmcore/ bootstrap/ \
 		./,$(addprefix $(dir),.*.cmd .*.o.flags *.o)))

vmmon-only/common/task.c

@@ -2322,23 +2322,12 @@ TaskSwitchToMonitor(VMCrossPage *crosspage)
    {
       uint64 raxGetsWiped, rcxGetsWiped;
 
-#ifdef CALL_NOSPEC
-      __asm__ __volatile__(CALL_NOSPEC
-                           : "=a" (raxGetsWiped),
-                             "=c" (rcxGetsWiped)
-                           : "0" (codePtr),
-                             "1" (crosspage),
-                             THUNK_TARGET(codePtr)
-                           : "rdx", "r8", "r9", "r10", "r11", "cc", "memory");
-#else
       __asm__ __volatile__("call *%%rax"
                            : "=a" (raxGetsWiped),
                              "=c" (rcxGetsWiped)
                            : "0" (codePtr),
                              "1" (crosspage)
                            : "rdx", "r8", "r9", "r10", "r11", "cc", "memory");
-#endif
-
    }
 #elif defined(_MSC_VER)
    /*

vmmon-only/include/compat_poll.h

@@ -1,30 +0,0 @@
-#ifndef __COMPAT_POLL_H__
-#define __COMPAT_POLL_H__
-
-#include <linux/poll.h>
-
-#if (LINUX_VERSION_CODE < KERNEL_VERSION(4, 18, 0))
-
-#ifndef __poll_t
-typedef unsigned int __poll_t;
-#endif
-
-static inline __poll_t compat_vfs_poll(struct file *file,
-				       struct poll_table_struct *pt)
-{
-	if (unlikely(!file->f_op->poll))
-		return DEFAULT_POLLMASK;
-	return file->f_op->poll(file, pt);
-}
-
-#else
-
-static inline __poll_t compat_vfs_poll(struct file *file,
-				       struct poll_table_struct *pt)
-{
-	return vfs_poll(file, pt);
-}
-
-#endif
-
-#endif /* __COMPAT_POLL_H__ */

vmmon-only/include/x86msr.h

@@ -466,9 +466,7 @@ typedef enum {
 #define MSR_K7_HWCR_SSEDIS         0x00008000ULL // Disable SSE bit
 #define MSR_K7_HWCR_MONMWAITUSEREN 0x00000400ULL // Enable MONITOR/MWAIT CPL>0
 #define MSR_K7_HWCR_TLBFFDIS       0x00000040ULL // Disable TLB Flush Filter
-#ifndef MSR_K7_HWCR_SMMLOCK
 #define MSR_K7_HWCR_SMMLOCK        0x00000001ULL // Lock SMM environment
-#endif
 
 #ifndef MSR_K8_SYSCFG
 #define MSR_K8_SYSCFG        0xc0010010

vmmon-only/linux/driver.c

@@ -982,7 +982,7 @@ LinuxDriverReadTSC(void *data,   // OUT: TSC values
  *-----------------------------------------------------------------------------
  */
 
-__always_inline static Bool
+__attribute__((always_inline)) static Bool
 LinuxDriverSyncReadTSCs(uint64 *delta) // OUT: TSC max - TSC min
 {
    TSCDelta tscDelta;

vmmon-only/linux/hostif.c

@@ -74,7 +74,6 @@
 
 #include "pgtbl.h"
 #include "versioned_atomic.h"
-#include "compat_poll.h"
 
 #if !defined(CONFIG_HIGH_RES_TIMERS)
 #error CONFIG_HIGH_RES_TIMERS required for acceptable performance
@@ -183,32 +182,6 @@ static void UnlockEntry(void *clientData, MemTrackEntry *entryPtr);
 uint8 monitorIPIVector;
 uint8 hvIPIVector;
 
-static unsigned long compat_totalram_pages(void)
-{
-#if LINUX_VERSION_CODE < KERNEL_VERSION(5, 0, 0)
-	return totalram_pages;
-#else
-	return totalram_pages();
-#endif
-}
-
-#if LINUX_VERSION_CODE >= KERNEL_VERSION(5, 0, 0)
-static void do_gettimeofday(struct timeval *tv)
-{
-	struct timespec64 now;
-
-	ktime_get_real_ts64(&now);
-	tv->tv_sec = now.tv_sec;
-	tv->tv_usec = now.tv_nsec / 1000;
-}
-#endif
-
-#if LINUX_VERSION_CODE < KERNEL_VERSION(5, 0, 0) && defined(VERIFY_WRITE)
-	#define write_access_ok(addr, size) access_ok(VERIFY_WRITE, addr, size)
-#else
-	#define write_access_ok(addr, size) access_ok(addr, size)
-#endif
-
 /*
  *-----------------------------------------------------------------------------
  *
@@ -1660,7 +1633,14 @@ unsigned int
 HostIF_EstimateLockedPageLimit(const VMDriver* vm,                // IN
                                unsigned int currentlyLockedPages) // IN
 {
-   unsigned int totalPhysicalPages = compat_totalram_pages();
+   /*
+    * This variable is available and exported to modules,
+    * since at least 2.6.0.
+    */
+
+   extern unsigned long totalram_pages;
+
+   unsigned int totalPhysicalPages = totalram_pages;
 
    /*
     * Use the memory information linux exports as of late for a more
@@ -2590,7 +2570,7 @@ HostIF_SemaphoreWait(VMDriver *vm,   // IN:
 
       poll_initwait(&table);
       current->state = TASK_INTERRUPTIBLE;
-      mask = compat_vfs_poll(file, &table.pt);
+      mask = file->f_op->poll(file, &table.pt);
       if (!(mask & (POLLIN | POLLERR | POLLHUP))) {
          vm->vmhost->vcpuSemaTask[vcpuid] = current;
          schedule_timeout(timeoutms * HZ / 1000);  // convert to Hz
@@ -3425,7 +3405,7 @@ HostIF_MapUserMem(VA addr,                  // IN: User memory virtual address
 
    ASSERT(handle);
 
-   if (!write_access_ok(p, size)) {
+   if (!access_ok(VERIFY_WRITE, p, size)) {
       printk(KERN_ERR "%s: Couldn't verify write to uva 0x%p with size %"
              FMTSZ"u\n", __func__, p, size);
 

vmnet-only/Makefile

@@ -107,7 +107,7 @@ prebuild:: ;
 postbuild:: ;
 
 $(DRIVER_KO): prebuild
-	$(MAKE) -C $(BUILD_DIR) M=$$PWD SRCROOT=$$PWD/$(SRCROOT) \
+	$(MAKE) -C $(BUILD_DIR) SUBDIRS=$$PWD SRCROOT=$$PWD/$(SRCROOT) \
 	  MODULEBUILDDIR=$(MODULEBUILDDIR) modules
 	$(MAKE) -C $$PWD SRCROOT=$$PWD/$(SRCROOT) \
 	  MODULEBUILDDIR=$(MODULEBUILDDIR) postbuild

vmnet-only/Makefile.kernel

@@ -32,6 +32,6 @@ $(DRIVER)-y := driver.o hub.o userif.o netif.o bridge.o procfs.o smac_compat.o \
 ####
 
 clean:
-	rm -rf $(DRIVER).o $(DRIVER).mod.o $(DRIVER).mod.c $(DRIVER).ko .cache.mk \
+	rm -rf $(DRIVER).o $(DRIVER).mod.o $(DRIVER).mod.c $(DRIVER).ko \
 	       .tmp_versions Module.symvers Modules.symvers Module.markers \
 	       modules.order $($(DRIVER)-y) .*.cmd .*.o.flags

vmnet-only/userif.c

@@ -85,12 +85,6 @@ extern unsigned int  vnet_max_qlen;
 #   define compat_kunmap(page) kunmap((page).p)
 #endif
 
-#if LINUX_VERSION_CODE < KERNEL_VERSION(5, 0, 0) && defined(VERIFY_WRITE)
-	#define write_access_ok(addr, size) access_ok(VERIFY_WRITE, addr, size)
-#else
-	#define write_access_ok(addr, size) access_ok(addr, size)
-#endif
-
 /*
  *-----------------------------------------------------------------------------
  *
@@ -148,7 +142,7 @@ VNetUserIfMapPtr(VA uAddr,        // IN: pointer to user memory
                  struct page **p, // OUT: locked page
                  void **ptr)      // OUT: kernel mapped pointer
 {
-   if (!write_access_ok((void *)uAddr, size) ||
+   if (!access_ok(VERIFY_WRITE, (void *)uAddr, size) ||
        (((uAddr + size - 1) & ~(PAGE_SIZE - 1)) !=
         (uAddr & ~(PAGE_SIZE - 1)))) {
       return -EINVAL;