Merge tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-tracegrafted

Pull tracing fixes from Steven Rostedt:

 - Fix error output of boot instance creation failure

   Currently if a boot instance creation fails, instead of printing out
   the name of the instance that failed, it prints "(null)". That is
   because it prints "cur_str" that had already been processed by
   strsep(). Print the saved name instead.

   While at it, print the error code of the failure.

 - Fix use-after-free for same named historgrams

   Histograms can be named so that they can be used in multiple events.
   But if the named histogram has a variable attached, the second event
   that uses the named histogram which duplicates it and needs to free
   the original after duplication leaves the old variable in place and
   still visible. If another histogram uses than variable, it will use
   the stale one which will try to reference the freed duplicate
   histogram and crash the kernel.

   Free the duplicate variables along with the duplicated histogram
   data.

 - Check return value of kthread_run() in event self test

   The events self tests uses a kthread for testing but does not check
   if it succeeded in creating a kthread. If the kthread creation were
   to fail, the code will still try to call kthread_stop() on the error
   returned.

 - Fix race between reading trace_pipe and updating subbuffer size

   If a user is reading the trace_pipe file at the same time they update
   the ring buffer sub-buffer size, can cause the trace_pipe read to
   read stale data. Add trace_access_lock() around updating the ring
   buffer sub-buffer size.

 - Fix eventfs_inode on failure path in creation of the events directory

   In the creation of the "events" directory, if after allocating the
   eventfs_inode a failure is detected, it calls cleanup_ei() which
   calls free_ei(). The free_ei() will test if eventfs_inode being freed
   has no children. It is a bug if it does. But on the failure case of
   the creation of the "events" directory, the children lists have not
   yet been initialized and the free will trigger a warning because
   list_empty() on an uninitialized list returns false.

   Move the initialization into init_ei() where it makes more sense and
   makes sure that a created eventfs_inode has its lists initialized
   upon creation.

 - Check return value of kthread_run() in ftrace direct sample code

   The sample code that shows how to use the ftrace direct calls does
   not test the return of kthread_run() to see if it succeeds. Return a
   failure if the kthread_run() doesn't succeed.

 - Clear user events state on fork in case of alloc failure

   On fork, the child gets a pointer to the parent's user events state.
   It makes a copy of it then updates the child's pointer to it. But if
   the allocation fails, the duplication function leaves the child with
   a pointer to its parent's descriptor. When the child cleans up its
   data, it will free the parent's descriptor while the parent is still
   using it.

   In the duplication function, set the child's user_event_mm to NULL
   before testing if the allocation succeeded, and when it exits it will
   not free the parent's descriptor.

 - Fix retry exhaustion in simple ring buffer reader swap

   simple_ring_buffer_swap_reader_page() starts with retry set to 8 and
   post-decrements it only after a failed link replacement. On the final
   attempt, a successful replacement leaves retry at zero, while a
   failed replacement leaves it at -1.

   But the check for success expects the retry value to be non-zero and
   exits with an error on zero. This is the opposite result. Fix it.

 - Fail nicely when the remote swap_reader_page() returns an error

   Currently, if the swap_reader_page() of a remote buffer fails, it
   triggers a WARN_ON_ONCE() and continues normally. Instead, have it
   exit with an error and a pr_warn() print instead of a full WARNING.

* tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  ring-buffer: Stop remote reader update when page swap fails
  tracing: Fix retry exhaustion in simple ring buffer reader swap
  tracing/user_events: Clear copied tracing state before fork duplication
  samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-multi-modify
  samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-modify
  eventfs: Initialize ei->children and ei->list in init_ei()
  tracing: Fix use-after-free in trace_pipe read on sub-buffer order change
  tracing: Fix crash passing ERR_PTR to kthread_stop()
  tracing: Fix use-after-free with same-name named triggers
  tracing: Fix logged instance name on creation failure

1 files changed, 236 insertions, 0 deletions

diff --git a/arch/arm64/Makefile b/arch/arm64/Makefile
new file mode 100644
index 000000000..6b005c8fe
--- /dev/null
+++ b/arch/arm64/Makefile
@@ -0,0 +1,236 @@
+#
+# arch/arm64/Makefile
+#
+# This file is included by the global makefile so that you can add your own
+# architecture-specific flags and dependencies.
+#
+# This file is subject to the terms and conditions of the GNU General Public
+# License.  See the file "COPYING" in the main directory of this archive
+# for more details.
+#
+# Copyright (C) 1995-2001 by Russell King
+
+LDFLAGS_vmlinux	:=--no-undefined -X --pic-veneer
+
+ifeq ($(CONFIG_RELOCATABLE), y)
+# Pass --no-apply-dynamic-relocs to restore pre-binutils-2.27 behaviour
+# for relative relocs, since this leads to better Image compression
+# with the relocation offsets always being zero.
+LDFLAGS_vmlinux	+= -shared -Bsymbolic -z notext --no-apply-dynamic-relocs
+endif
+
+ifeq ($(CONFIG_ARM64_ERRATUM_843419),y)
+LDFLAGS_vmlinux	+= --fix-cortex-a53-843419
+endif
+
+cc_has_k_constraint := $(call try-run,echo				\
+	'int main(void) {						\
+		asm volatile("and w0, w0, %w0" :: "K" (4294967295));	\
+		return 0;						\
+	}' | $(CC) -S -x c -o "$$TMP" -,,-DCONFIG_CC_HAS_K_CONSTRAINT=1)
+
+ifeq ($(CONFIG_BROKEN_GAS_INST),y)
+$(warning Detected assembler with broken .inst; disassembly will be unreliable)
+endif
+
+# The GCC option -ffreestanding is required in order to compile code containing
+# ARM/NEON intrinsics in a non C99-compliant environment (such as the kernel)
+CC_FLAGS_FPU	:= -ffreestanding
+# Enable <arm_neon.h>
+CC_FLAGS_FPU	+= -isystem $(shell $(CC) -print-file-name=include)
+CC_FLAGS_NO_FPU	:= -mgeneral-regs-only
+
+KBUILD_CFLAGS	+= $(CC_FLAGS_NO_FPU) \
+		   $(compat_vdso) $(cc_has_k_constraint)
+KBUILD_CFLAGS	+= $(call cc-disable-warning, psabi)
+KBUILD_AFLAGS	+= $(compat_vdso)
+
+ifeq ($(call rustc-min-version, 108500),y)
+KBUILD_RUSTFLAGS += --target=aarch64-unknown-none-softfloat
+else
+KBUILD_RUSTFLAGS += --target=aarch64-unknown-none -Ctarget-feature="-neon"
+endif
+
+KBUILD_CFLAGS	+= $(call cc-option,-mabi=lp64)
+KBUILD_AFLAGS	+= $(call cc-option,-mabi=lp64)
+
+# Avoid generating .eh_frame* sections.
+ifneq ($(CONFIG_UNWIND_TABLES),y)
+KBUILD_CFLAGS	+= -fno-asynchronous-unwind-tables -fno-unwind-tables
+KBUILD_AFLAGS	+= -fno-asynchronous-unwind-tables -fno-unwind-tables
+KBUILD_RUSTFLAGS += -Cforce-unwind-tables=n
+else
+KBUILD_CFLAGS	+= -fasynchronous-unwind-tables
+KBUILD_AFLAGS	+= -fasynchronous-unwind-tables
+KBUILD_RUSTFLAGS += -Cforce-unwind-tables=y -Zuse-sync-unwind=n
+# Work around rustc bug on compilers without
+# https://github.com/rust-lang/rust/pull/156973.
+KBUILD_RUSTFLAGS += $(if $(call rustc-min-version,109800),,-Zllvm_module_flag=uwtable:u32:2:max)
+endif
+
+ifeq ($(CONFIG_STACKPROTECTOR_PER_TASK),y)
+prepare: stack_protector_prepare
+stack_protector_prepare: prepare0
+	$(eval KBUILD_CFLAGS += -mstack-protector-guard=sysreg		  \
+				-mstack-protector-guard-reg=sp_el0	  \
+				-mstack-protector-guard-offset=$(shell	  \
+			awk '{if ($$2 == "TSK_STACK_CANARY") print $$3;}' \
+				$(objtree)/include/generated/asm-offsets.h))
+endif
+
+ifeq ($(CONFIG_ARM64_BTI_KERNEL),y)
+  KBUILD_CFLAGS += -mbranch-protection=pac-ret+bti
+  KBUILD_RUSTFLAGS += -Zbranch-protection=bti,pac-ret
+else ifeq ($(CONFIG_ARM64_PTR_AUTH_KERNEL),y)
+  KBUILD_RUSTFLAGS += -Zbranch-protection=pac-ret
+  ifeq ($(CONFIG_CC_HAS_BRANCH_PROT_PAC_RET),y)
+    KBUILD_CFLAGS += -mbranch-protection=pac-ret
+  else
+    KBUILD_CFLAGS += -msign-return-address=non-leaf
+  endif
+else
+  KBUILD_CFLAGS += $(call cc-option,-mbranch-protection=none)
+endif
+
+# Tell the assembler to support instructions from the latest target
+# architecture.
+#
+# For non-integrated assemblers we'll pass this on the command line, and for
+# integrated assemblers we'll define ARM64_ASM_ARCH and ARM64_ASM_PREAMBLE for
+# inline usage.
+#
+# We cannot pass the same arch flag to the compiler as this would allow it to
+# freely generate instructions which are not supported by earlier architecture
+# versions, which would prevent a single kernel image from working on earlier
+# hardware.
+ifeq ($(CONFIG_AS_HAS_ARMV8_5), y)
+  asm-arch := armv8.5-a
+else
+  asm-arch := armv8.4-a
+endif
+
+ifdef asm-arch
+KBUILD_CFLAGS	+= -Wa,-march=$(asm-arch) \
+		   -DARM64_ASM_ARCH='"$(asm-arch)"'
+endif
+
+ifeq ($(CONFIG_SHADOW_CALL_STACK), y)
+KBUILD_CFLAGS	+= -ffixed-x18
+KBUILD_RUSTFLAGS += -Zfixed-x18
+endif
+
+ifeq ($(CONFIG_CPU_BIG_ENDIAN), y)
+KBUILD_CPPFLAGS	+= -mbig-endian
+CHECKFLAGS	+= -D__AARCH64EB__
+# Prefer the baremetal ELF build target, but not all toolchains include
+# it so fall back to the standard linux version if needed.
+KBUILD_LDFLAGS	+= -EB $(call ld-option, -maarch64elfb, -maarch64linuxb -z norelro)
+UTS_MACHINE	:= aarch64_be
+else
+KBUILD_CPPFLAGS	+= -mlittle-endian
+CHECKFLAGS	+= -D__AARCH64EL__
+# Same as above, prefer ELF but fall back to linux target if needed.
+KBUILD_LDFLAGS	+= -EL $(call ld-option, -maarch64elf, -maarch64linux -z norelro)
+UTS_MACHINE	:= aarch64
+endif
+
+ifeq ($(CONFIG_LD_IS_LLD), y)
+KBUILD_LDFLAGS	+= -z norelro
+endif
+
+CHECKFLAGS	+= -D__aarch64__
+
+ifeq ($(CONFIG_DYNAMIC_FTRACE_WITH_CALL_OPS),y)
+  KBUILD_CPPFLAGS += -DCC_USING_PATCHABLE_FUNCTION_ENTRY
+  CC_FLAGS_FTRACE := -fpatchable-function-entry=4,2
+else ifeq ($(CONFIG_DYNAMIC_FTRACE_WITH_ARGS),y)
+  KBUILD_CPPFLAGS += -DCC_USING_PATCHABLE_FUNCTION_ENTRY
+  CC_FLAGS_FTRACE := -fpatchable-function-entry=2
+endif
+
+ifeq ($(CONFIG_KASAN_SW_TAGS), y)
+KASAN_SHADOW_SCALE_SHIFT := 4
+else ifeq ($(CONFIG_KASAN_GENERIC), y)
+KASAN_SHADOW_SCALE_SHIFT := 3
+endif
+
+KBUILD_CFLAGS += -DKASAN_SHADOW_SCALE_SHIFT=$(KASAN_SHADOW_SCALE_SHIFT)
+KBUILD_CPPFLAGS += -DKASAN_SHADOW_SCALE_SHIFT=$(KASAN_SHADOW_SCALE_SHIFT)
+KBUILD_AFLAGS += -DKASAN_SHADOW_SCALE_SHIFT=$(KASAN_SHADOW_SCALE_SHIFT)
+
+libs-y		:= arch/arm64/lib/ $(libs-y)
+libs-$(CONFIG_EFI_STUB) += $(objtree)/drivers/firmware/efi/libstub/lib.a
+
+# Default target when executing plain make
+boot		:= arch/arm64/boot
+
+BOOT_TARGETS	:= Image vmlinuz.efi image.fit
+
+PHONY += $(BOOT_TARGETS)
+
+ifeq ($(CONFIG_EFI_ZBOOT),)
+KBUILD_IMAGE	:= $(boot)/Image.gz
+else
+KBUILD_IMAGE	:= $(boot)/vmlinuz.efi
+endif
+
+all:	$(notdir $(KBUILD_IMAGE))
+
+image.fit: dtbs
+
+vmlinuz.efi image.fit: Image
+$(BOOT_TARGETS): vmlinux
+	$(Q)$(MAKE) $(build)=$(boot) $(boot)/$@
+
+Image.%: Image
+	$(Q)$(MAKE) $(build)=$(boot) $(boot)/$@
+
+ifeq ($(CONFIG_COMPRESSED_INSTALL),y)
+ DEFAULT_KBUILD_IMAGE = $(KBUILD_IMAGE)
+else
+ DEFAULT_KBUILD_IMAGE = $(boot)/Image
+endif
+
+install: KBUILD_IMAGE := $(DEFAULT_KBUILD_IMAGE)
+install zinstall:
+	$(call cmd,install)
+
+archprepare:
+	$(Q)$(MAKE) $(build)=arch/arm64/tools kapi
+
+ifeq ($(KBUILD_EXTMOD),)
+# We need to generate vdso-offsets.h before compiling certain files in kernel/.
+# In order to do that, we should use the archprepare target, but we can't since
+# asm-offsets.h is included in some files used to generate vdso-offsets.h, and
+# asm-offsets.h is built in prepare0, for which archprepare is a dependency.
+# Therefore we need to generate the header after prepare0 has been made, hence
+# this hack.
+prepare: vdso_prepare
+vdso_prepare: prepare0
+	$(Q)$(MAKE) $(build)=arch/arm64/kernel/vdso \
+	include/generated/vdso-offsets.h arch/arm64/kernel/vdso/vdso.so
+ifdef CONFIG_COMPAT_VDSO
+	$(Q)$(MAKE) $(build)=arch/arm64/kernel/vdso32 \
+	arch/arm64/kernel/vdso32/vdso.so
+endif
+endif
+
+vdso-install-y				+= arch/arm64/kernel/vdso/vdso.so.dbg
+vdso-install-$(CONFIG_COMPAT_VDSO)	+= arch/arm64/kernel/vdso32/vdso32.so.dbg
+
+include $(srctree)/scripts/Makefile.defconf
+
+PHONY += virtconfig
+virtconfig:
+	$(call merge_into_defconfig_override,defconfig,virt)
+
+define archhelp
+  echo  '* Image.gz      - Compressed kernel image (arch/$(ARCH)/boot/Image.gz)'
+  echo  '  Image         - Uncompressed kernel image (arch/$(ARCH)/boot/Image)'
+  echo  '  image.fit     - Flat Image Tree (arch/$(ARCH)/boot/image.fit)'
+  echo  '  install       - Install kernel (compressed if COMPRESSED_INSTALL set)'
+  echo  '  zinstall      - Install compressed kernel'
+  echo  '                  Install using (your) ~/bin/installkernel or'
+  echo  '                  (distribution) /sbin/installkernel or'
+  echo  '                  install to $$(INSTALL_PATH) and run lilo'
+endef