Merge tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux

Pull arm64 fixes from Will Deacon:
"The usual summary below, but the main fix is for the fast GUP lockless
page-table walk when we have a combination of compile-time and
run-time folding of the p4d and the pud respectively.

- Remove some redundant Kconfig conditionals

- Fix string output in ptrace selftest

- Fix fast GUP crashes in some page-table configurations

- Remove obsolete linker option when building the vDSO

- Fix some sysreg field definitions for the GIC"

* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
arm64: mm: Fix lockless walks with static and dynamic page-table folding
arm64/sysreg: Correct the values for GICv4.1
arm64/vdso: Remove --hash-style=sysv
kselftest: missing arg in ptrace.c
arm64/Kconfig: Remove redundant 'if HAVE_FUNCTION_GRAPH_TRACER'
arm64: remove redundant 'if HAVE_ARCH_KASAN' in Kconfig

arch/arm64/Kconfig

···
 	select HAVE_ARCH_JUMP_LABEL
 	select HAVE_ARCH_JUMP_LABEL_RELATIVE
 	select HAVE_ARCH_KASAN
-	select HAVE_ARCH_KASAN_VMALLOC if HAVE_ARCH_KASAN
-	select HAVE_ARCH_KASAN_SW_TAGS if HAVE_ARCH_KASAN
-	select HAVE_ARCH_KASAN_HW_TAGS if (HAVE_ARCH_KASAN && ARM64_MTE)
+	select HAVE_ARCH_KASAN_VMALLOC
+	select HAVE_ARCH_KASAN_SW_TAGS
+	select HAVE_ARCH_KASAN_HW_TAGS if ARM64_MTE
 	# Some instrumentation may be unsound, hence EXPERT
 	select HAVE_ARCH_KCSAN if EXPERT
 	select HAVE_ARCH_KFENCE
···
 	select HAVE_FTRACE_MCOUNT_RECORD
 	select HAVE_FUNCTION_TRACER
 	select HAVE_FUNCTION_ERROR_INJECTION
-	select HAVE_FUNCTION_GRAPH_RETVAL if HAVE_FUNCTION_GRAPH_TRACER
 	select HAVE_FUNCTION_GRAPH_TRACER
+	select HAVE_FUNCTION_GRAPH_RETVAL
 	select HAVE_GCC_PLUGINS
 	select HAVE_HARDLOCKUP_DETECTOR_PERF if PERF_EVENTS && \
 		HW_PERF_EVENTS && HAVE_PERF_EVENTS_NMI

arch/arm64/include/asm/pgtable.h

···
 
 #define p4d_offset_kimg(dir,addr)	((p4d_t *)dir)
 
+static inline
+p4d_t *p4d_offset_lockless_folded(pgd_t *pgdp, pgd_t pgd, unsigned long addr)
+{
+	/*
+	 * With runtime folding of the pud, pud_offset_lockless() passes
+	 * the 'pgd_t *' we return here to p4d_to_folded_pud(), which
+	 * will offset the pointer assuming that it points into
+	 * a page-table page. However, the fast GUP path passes us a
+	 * pgd_t allocated on the stack and so we must use the original
+	 * pointer in 'pgdp' to construct the p4d pointer instead of
+	 * using the generic p4d_offset_lockless() implementation.
+	 *
+	 * Note: reusing the original pointer means that we may
+	 * dereference the same (live) page-table entry multiple times.
+	 * This is safe because it is still only loaded once in the
+	 * context of each level and the CPU guarantees same-address
+	 * read-after-read ordering.
+	 */
+	return p4d_offset(pgdp, addr);
+}
+#define p4d_offset_lockless p4d_offset_lockless_folded
+
 #endif  /* CONFIG_PGTABLE_LEVELS > 4 */
 
 #define pgd_ERROR(e)	\

arch/arm64/kernel/vdso/Makefile

···
 # potential future proofing if we end up with internal calls to the exported
 # routines, as x86 does (see 6f121e548f83 ("x86, vdso: Reimplement vdso.so
 # preparation in build-time C")).
-ldflags-y := -shared -soname=linux-vdso.so.1 --hash-style=sysv	\
+ldflags-y := -shared -soname=linux-vdso.so.1 \
 	     -Bsymbolic --build-id=sha1 -n $(btildflags-y)
 
 ifdef CONFIG_LD_ORPHAN_WARN

arch/arm64/kernel/vdso32/Makefile

···
 # From arm vDSO Makefile
 VDSO_LDFLAGS += -Bsymbolic --no-undefined -soname=linux-vdso.so.1
 VDSO_LDFLAGS += -z max-page-size=4096 -z common-page-size=4096
-VDSO_LDFLAGS += -shared --hash-style=sysv --build-id=sha1
+VDSO_LDFLAGS += -shared --build-id=sha1
 VDSO_LDFLAGS += --orphan-handling=$(CONFIG_LD_ORPHAN_WARN_LEVEL)
 
 

arch/arm64/tools/sysreg

···
 UnsignedEnum	31:28	GIC
 	0b0000	NI
 	0b0001	GICv3
-	0b0010	GICv4p1
+	0b0011	GICv4p1
 EndEnum
 UnsignedEnum	27:24	Virt_frac
 	0b0000	NI
···
 UnsignedEnum	27:24	GIC
 	0b0000	NI
 	0b0001	IMP
-	0b0010	V4P1
+	0b0011	V4P1
 EndEnum
 SignedEnum	23:20	AdvSIMD
 	0b0000	IMP

tools/testing/selftests/arm64/abi/ptrace.c

···
 		/* Zero is not currently architecturally valid */
 		ksft_test_result(arch, "%s_arch_set\n", type_name);
 	} else {
-		ksft_test_result_skip("%s_arch_set\n");
+		ksft_test_result_skip("%s_arch_set\n", type_name);
 	}
 }