Merge branch 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 PTI and Spectre related fixes and updates from Ingo Molnar:
 "Here's the latest set of Spectre and PTI related fixes and updates:

  Spectre:
   - Add entry code register clearing to reduce the Spectre attack
     surface
   - Update the Spectre microcode blacklist
   - Inline the KVM Spectre helpers to get close to v4.14 performance
     again.
   - Fix indirect_branch_prediction_barrier()
   - Fix/improve Spectre related kernel messages
   - Fix array_index_nospec_mask() asm constraint
   - KVM: fix two MSR handling bugs

  PTI:
   - Fix a paranoid entry PTI CR3 handling bug
   - Fix comments

  objtool:
   - Fix paranoid_entry() frame pointer warning
   - Annotate WARN()-related UD2 as reachable
   - Various fixes
   - Add Add Peter Zijlstra as objtool co-maintainer

  Misc:
   - Various x86 entry code self-test fixes
   - Improve/simplify entry code stack frame generation and handling
     after recent heavy-handed PTI and Spectre changes. (There's two
     more WIP improvements expected here.)
   - Type fix for cache entries

  There's also some low risk non-fix changes I've included in this
  branch to reduce backporting conflicts:

   - rename a confusing x86_cpu field name
   - de-obfuscate the naming of single-TLB flushing primitives"

* 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (41 commits)
  x86/entry/64: Fix CR3 restore in paranoid_exit()
  x86/cpu: Change type of x86_cache_size variable to unsigned int
  x86/spectre: Fix an error message
  x86/cpu: Rename cpu_data.x86_mask to cpu_data.x86_stepping
  selftests/x86/mpx: Fix incorrect bounds with old _sigfault
  x86/mm: Rename flush_tlb_single() and flush_tlb_one() to __flush_tlb_one_[user|kernel]()
  x86/speculation: Add <asm/msr-index.h> dependency
  nospec: Move array_index_nospec() parameter checking into separate macro
  x86/speculation: Fix up array_index_nospec_mask() asm constraint
  x86/debug: Use UD2 for WARN()
  x86/debug, objtool: Annotate WARN()-related UD2 as reachable
  objtool: Fix segfault in ignore_unreachable_insn()
  selftests/x86: Disable tests requiring 32-bit support on pure 64-bit systems
  selftests/x86: Do not rely on "int $0x80" in single_step_syscall.c
  selftests/x86: Do not rely on "int $0x80" in test_mremap_vdso.c
  selftests/x86: Fix build bug caused by the 5lvl test which has been moved to the VM directory
  selftests/x86/pkeys: Remove unused functions
  selftests/x86: Clean up and document sscanf() usage
  selftests/x86: Fix vDSO selftest segfault for vsyscall=none
  x86/entry/64: Remove the unused 'icebp' macro
  ...

1 files changed, 8 insertions, 3 deletions

diff --git a/tools/testing/selftests/x86/test_vsyscall.c b/tools/testing/selftests/x86/test_vsyscall.c
index 7a744fa7b786..be81621446f0 100644
--- a/tools/testing/selftests/x86/test_vsyscall.c
+++ b/tools/testing/selftests/x86/test_vsyscall.c
@@ -33,6 +33,9 @@
 # endif
 #endif
 
+/* max length of lines in /proc/self/maps - anything longer is skipped here */
+#define MAPS_LINE_LEN 128
+
 static void sethandler(int sig, void (*handler)(int, siginfo_t *, void *),
 		       int flags)
 {
@@ -98,7 +101,7 @@ static int init_vsys(void)
 #ifdef __x86_64__
 	int nerrs = 0;
 	FILE *maps;
-	char line[128];
+	char line[MAPS_LINE_LEN];
 	bool found = false;
 
 	maps = fopen("/proc/self/maps", "r");
@@ -108,10 +111,12 @@ static int init_vsys(void)
 		return 0;
 	}
 
-	while (fgets(line, sizeof(line), maps)) {
+	while (fgets(line, MAPS_LINE_LEN, maps)) {
 		char r, x;
 		void *start, *end;
-		char name[128];
+		char name[MAPS_LINE_LEN];
+
+		/* sscanf() is safe here as strlen(name) >= strlen(line) */
 		if (sscanf(line, "%p-%p %c-%cp %*x %*x:%*x %*u %s",
 			   &start, &end, &r, &x, name) != 5)
 			continue;