Merge branch 'akpm' (patches from Andrew)

Merge third patch-bomb from Andrew Morton:

 - more ocfs2 changes

 - a few hotfixes

 - Andy's compat cleanups

 - misc fixes to fatfs, ptrace, coredump, cpumask, creds, eventfd,
   panic, ipmi, kgdb, profile, kfifo, ubsan, etc.

 - many rapidio updates: fixes, new drivers.

 - kcov: kernel code coverage feature.  Like gcov, but not
   "prohibitively expensive".

 - extable code consolidation for various archs

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (81 commits)
  ia64/extable: use generic search and sort routines
  x86/extable: use generic search and sort routines
  s390/extable: use generic search and sort routines
  alpha/extable: use generic search and sort routines
  kernel/...: convert pr_warning to pr_warn
  drivers: dma-coherent: use memset_io for DMA_MEMORY_IO mappings
  drivers: dma-coherent: use MEMREMAP_WC for DMA_MEMORY_MAP
  memremap: add MEMREMAP_WC flag
  memremap: don't modify flags
  kernel/signal.c: add compile-time check for __ARCH_SI_PREAMBLE_SIZE
  mm/mprotect.c: don't imply PROT_EXEC on non-exec fs
  ipc/sem: make semctl setting sempid consistent
  ubsan: fix tree-wide -Wmaybe-uninitialized false positives
  kfifo: fix sparse complaints
  scripts/gdb: account for changes in module data structure
  scripts/gdb: add cmdline reader command
  scripts/gdb: add version command
  kernel: add kcov code coverage
  profile: hide unused functions when !CONFIG_PROC_FS
  hpwdt: use nmi_panic() when kernel panics in NMI handler
  ...

15 files changed, 43 insertions, 114 deletions

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 8b680a5cb25b..54478b7635de 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -28,6 +28,7 @@ config X86
 	select ARCH_HAS_ELF_RANDOMIZE
 	select ARCH_HAS_FAST_MULTIPLIER
 	select ARCH_HAS_GCOV_PROFILE_ALL
+	select ARCH_HAS_KCOV			if X86_64
 	select ARCH_HAS_PMEM_API		if X86_64
 	select ARCH_HAS_MMIO_FLUSH
 	select ARCH_HAS_SG_CHAIN
diff --git a/arch/x86/boot/Makefile b/arch/x86/boot/Makefile
index 0bf6749522d9..b1ef9e489084 100644
--- a/arch/x86/boot/Makefile
+++ b/arch/x86/boot/Makefile
@@ -12,6 +12,13 @@
 KASAN_SANITIZE			:= n
 OBJECT_FILES_NON_STANDARD	:= y
 
+# Kernel does not boot with kcov instrumentation here.
+# One of the problems observed was insertion of __sanitizer_cov_trace_pc()
+# callback into middle of per-cpu data enabling code. Thus the callback observed
+# inconsistent state and crashed. We are interested mostly in syscall coverage,
+# so boot code is not interesting anyway.
+KCOV_INSTRUMENT		:= n
+
 # If you want to preset the SVGA mode, uncomment the next line and
 # set SVGA_MODE to whatever number you want.
 # Set it to -DSVGA_MODE=NORMAL_VGA if you just want the EGA/VGA mode.
diff --git a/arch/x86/boot/compressed/Makefile b/arch/x86/boot/compressed/Makefile
index 5e1d26e09407..6915ff2bd996 100644
--- a/arch/x86/boot/compressed/Makefile
+++ b/arch/x86/boot/compressed/Makefile
@@ -19,6 +19,9 @@
 KASAN_SANITIZE			:= n
 OBJECT_FILES_NON_STANDARD	:= y
 
+# Prevents link failures: __sanitizer_cov_trace_pc() is not linked in.
+KCOV_INSTRUMENT		:= n
+
 targets := vmlinux vmlinux.bin vmlinux.bin.gz vmlinux.bin.bz2 vmlinux.bin.lzma \
 	vmlinux.bin.xz vmlinux.bin.lzo vmlinux.bin.lz4
 
diff --git a/arch/x86/entry/vdso/Makefile b/arch/x86/entry/vdso/Makefile
index f9fb859c98b9..6874da5f67fc 100644
--- a/arch/x86/entry/vdso/Makefile
+++ b/arch/x86/entry/vdso/Makefile
@@ -7,6 +7,9 @@ KASAN_SANITIZE			:= n
 UBSAN_SANITIZE			:= n
 OBJECT_FILES_NON_STANDARD	:= y
 
+# Prevents link failures: __sanitizer_cov_trace_pc() is not linked in.
+KCOV_INSTRUMENT		:= n
+
 VDSO64-$(CONFIG_X86_64)		:= y
 VDSOX32-$(CONFIG_X86_X32_ABI)	:= y
 VDSO32-$(CONFIG_X86_32)		:= y
diff --git a/arch/x86/include/asm/compat.h b/arch/x86/include/asm/compat.h
index acdee09228b3..ebb102e1bbc7 100644
--- a/arch/x86/include/asm/compat.h
+++ b/arch/x86/include/asm/compat.h
@@ -316,9 +316,10 @@ static inline bool is_x32_task(void)
 	return false;
 }
 
-static inline bool is_compat_task(void)
+static inline bool in_compat_syscall(void)
 {
 	return is_ia32_task() || is_x32_task();
 }
+#define in_compat_syscall in_compat_syscall	/* override the generic impl */
 
 #endif /* _ASM_X86_COMPAT_H */
diff --git a/arch/x86/include/asm/ftrace.h b/arch/x86/include/asm/ftrace.h
index 24938852db30..21b66dbf3601 100644
--- a/arch/x86/include/asm/ftrace.h
+++ b/arch/x86/include/asm/ftrace.h
@@ -58,7 +58,7 @@ int ftrace_int3_handler(struct pt_regs *regs);
 #define ARCH_TRACE_IGNORE_COMPAT_SYSCALLS 1
 static inline bool arch_trace_is_compat_syscall(struct pt_regs *regs)
 {
-	if (is_compat_task())
+	if (in_compat_syscall())
 		return true;
 	return false;
 }
diff --git a/arch/x86/include/asm/uaccess.h b/arch/x86/include/asm/uaccess.h
index 88bff6dd23ad..a969ae607be8 100644
--- a/arch/x86/include/asm/uaccess.h
+++ b/arch/x86/include/asm/uaccess.h
@@ -105,9 +105,8 @@ static inline bool __chk_range_not_ok(unsigned long addr, unsigned long size, un
 struct exception_table_entry {
 	int insn, fixup, handler;
 };
-/* This is not the generic standard exception_table_entry format */
-#define ARCH_HAS_SORT_EXTABLE
-#define ARCH_HAS_SEARCH_EXTABLE
+
+#define ARCH_HAS_RELATIVE_EXTABLE
 
 extern int fixup_exception(struct pt_regs *regs, int trapnr);
 extern bool ex_has_fault_handler(unsigned long ip);
diff --git a/arch/x86/kernel/Makefile b/arch/x86/kernel/Makefile
index d5fb0871aba3..adaae2c781c1 100644
--- a/arch/x86/kernel/Makefile
+++ b/arch/x86/kernel/Makefile
@@ -25,6 +25,12 @@ OBJECT_FILES_NON_STANDARD_relocate_kernel_$(BITS).o	:= y
 OBJECT_FILES_NON_STANDARD_mcount_$(BITS).o		:= y
 OBJECT_FILES_NON_STANDARD_test_nx.o			:= y
 
+# If instrumentation of this dir is enabled, boot hangs during first second.
+# Probably could be more selective here, but note that files related to irqs,
+# boot, dumpstack/stacktrace, etc are either non-interesting or can lead to
+# non-deterministic coverage.
+KCOV_INSTRUMENT		:= n
+
 CFLAGS_irq.o := -I$(src)/../include/asm/trace
 
 obj-y			:= process_$(BITS).o signal.o
diff --git a/arch/x86/kernel/apic/Makefile b/arch/x86/kernel/apic/Makefile
index 8bb12ddc5db8..8e63ebdcbd0b 100644
--- a/arch/x86/kernel/apic/Makefile
+++ b/arch/x86/kernel/apic/Makefile
@@ -2,6 +2,10 @@
 # Makefile for local APIC drivers and for the IO-APIC code
 #
 
+# Leads to non-deterministic coverage that is not a function of syscall inputs.
+# In particualr, smp_apic_timer_interrupt() is called in random places.
+KCOV_INSTRUMENT		:= n
+
 obj-$(CONFIG_X86_LOCAL_APIC)	+= apic.o apic_noop.o ipi.o vector.o
 obj-y				+= hw_nmi.o
 
diff --git a/arch/x86/kernel/cpu/Makefile b/arch/x86/kernel/cpu/Makefile
index 0d373d7affc8..4a8697f7d4ef 100644
--- a/arch/x86/kernel/cpu/Makefile
+++ b/arch/x86/kernel/cpu/Makefile
@@ -8,6 +8,10 @@ CFLAGS_REMOVE_common.o = -pg
 CFLAGS_REMOVE_perf_event.o = -pg
 endif
 
+# If these files are instrumented, boot hangs during the first second.
+KCOV_INSTRUMENT_common.o := n
+KCOV_INSTRUMENT_perf_event.o := n
+
 # Make sure load_percpu_segment has no stackprotector
 nostackp := $(call cc-option, -fno-stack-protector)
 CFLAGS_common.o		:= $(nostackp)
diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c
index 776229e98202..dfa2781610e8 100644
--- a/arch/x86/kernel/process_64.c
+++ b/arch/x86/kernel/process_64.c
@@ -478,7 +478,7 @@ void set_personality_ia32(bool x32)
 		if (current->mm)
 			current->mm->context.ia32_compat = TIF_X32;
 		current->personality &= ~READ_IMPLIES_EXEC;
-		/* is_compat_task() uses the presence of the x32
+		/* in_compat_syscall() uses the presence of the x32
 		   syscall bit flag to determine compat status */
 		current_thread_info()->status &= ~TS_COMPAT;
 	} else {
diff --git a/arch/x86/lib/Makefile b/arch/x86/lib/Makefile
index a501fa25da41..72a576752a7e 100644
--- a/arch/x86/lib/Makefile
+++ b/arch/x86/lib/Makefile
@@ -2,6 +2,9 @@
 # Makefile for x86 specific library files.
 #
 
+# Produces uninteresting flaky coverage.
+KCOV_INSTRUMENT_delay.o	:= n
+
 inat_tables_script = $(srctree)/arch/x86/tools/gen-insn-attr-x86.awk
 inat_tables_maps = $(srctree)/arch/x86/lib/x86-opcode-map.txt
 quiet_cmd_inat_tables = GEN     $@
diff --git a/arch/x86/mm/Makefile b/arch/x86/mm/Makefile
index 67cf2e1e557b..f98913258c63 100644
--- a/arch/x86/mm/Makefile
+++ b/arch/x86/mm/Makefile
@@ -1,3 +1,6 @@
+# Kernel does not boot with instrumentation of tlb.c.
+KCOV_INSTRUMENT_tlb.o	:= n
+
 obj-y	:=  init.o init_$(BITS).o fault.o ioremap.o extable.o pageattr.o mmap.o \
 	    pat.o pgtable.o physaddr.o gup.o setup_nx.o
 
diff --git a/arch/x86/mm/extable.c b/arch/x86/mm/extable.c
index 9dd7e4b7fcde..82447b3fba38 100644
--- a/arch/x86/mm/extable.c
+++ b/arch/x86/mm/extable.c
@@ -1,17 +1,10 @@
 #include <linux/module.h>
-#include <linux/spinlock.h>
-#include <linux/sort.h>
 #include <asm/uaccess.h>
 
 typedef bool (*ex_handler_t)(const struct exception_table_entry *,
 			    struct pt_regs *, int);
 
 static inline unsigned long
-ex_insn_addr(const struct exception_table_entry *x)
-{
-	return (unsigned long)&x->insn + x->insn;
-}
-static inline unsigned long
 ex_fixup_addr(const struct exception_table_entry *x)
 {
 	return (unsigned long)&x->fixup + x->fixup;
@@ -110,104 +103,3 @@ int __init early_fixup_exception(unsigned long *ip)
 	*ip = new_ip;
 	return 1;
 }
-
-/*
- * Search one exception table for an entry corresponding to the
- * given instruction address, and return the address of the entry,
- * or NULL if none is found.
- * We use a binary search, and thus we assume that the table is
- * already sorted.
- */
-const struct exception_table_entry *
-search_extable(const struct exception_table_entry *first,
-	       const struct exception_table_entry *last,
-	       unsigned long value)
-{
-	while (first <= last) {
-		const struct exception_table_entry *mid;
-		unsigned long addr;
-
-		mid = ((last - first) >> 1) + first;
-		addr = ex_insn_addr(mid);
-		if (addr < value)
-			first = mid + 1;
-		else if (addr > value)
-			last = mid - 1;
-		else
-			return mid;
-        }
-        return NULL;
-}
-
-/*
- * The exception table needs to be sorted so that the binary
- * search that we use to find entries in it works properly.
- * This is used both for the kernel exception table and for
- * the exception tables of modules that get loaded.
- *
- */
-static int cmp_ex(const void *a, const void *b)
-{
-	const struct exception_table_entry *x = a, *y = b;
-
-	/*
-	 * This value will always end up fittin in an int, because on
-	 * both i386 and x86-64 the kernel symbol-reachable address
-	 * space is < 2 GiB.
-	 *
-	 * This compare is only valid after normalization.
-	 */
-	return x->insn - y->insn;
-}
-
-void sort_extable(struct exception_table_entry *start,
-		  struct exception_table_entry *finish)
-{
-	struct exception_table_entry *p;
-	int i;
-
-	/* Convert all entries to being relative to the start of the section */
-	i = 0;
-	for (p = start; p < finish; p++) {
-		p->insn += i;
-		i += 4;
-		p->fixup += i;
-		i += 4;
-		p->handler += i;
-		i += 4;
-	}
-
-	sort(start, finish - start, sizeof(struct exception_table_entry),
-	     cmp_ex, NULL);
-
-	/* Denormalize all entries */
-	i = 0;
-	for (p = start; p < finish; p++) {
-		p->insn -= i;
-		i += 4;
-		p->fixup -= i;
-		i += 4;
-		p->handler -= i;
-		i += 4;
-	}
-}
-
-#ifdef CONFIG_MODULES
-/*
- * If the exception table is sorted, any referring to the module init
- * will be at the beginning or the end.
- */
-void trim_init_extable(struct module *m)
-{
-	/*trim the beginning*/
-	while (m->num_exentries &&
-	       within_module_init(ex_insn_addr(&m->extable[0]), m)) {
-		m->extable++;
-		m->num_exentries--;
-	}
-	/*trim the end*/
-	while (m->num_exentries &&
-	       within_module_init(ex_insn_addr(&m->extable[m->num_exentries-1]), m))
-		m->num_exentries--;
-}
-#endif /* CONFIG_MODULES */
diff --git a/arch/x86/realmode/rm/Makefile b/arch/x86/realmode/rm/Makefile
index 053abe7b0ef7..b95964610ea7 100644
--- a/arch/x86/realmode/rm/Makefile
+++ b/arch/x86/realmode/rm/Makefile
@@ -9,6 +9,9 @@
 KASAN_SANITIZE			:= n
 OBJECT_FILES_NON_STANDARD	:= y
 
+# Prevents link failures: __sanitizer_cov_trace_pc() is not linked in.
+KCOV_INSTRUMENT		:= n
+
 always := realmode.bin realmode.relocs
 
 wakeup-objs	:= wakeup_asm.o wakemain.o video-mode.o