Merge tag 'for-linus' of https://github.com/openrisc/linux

Pull OpenRISC updates from Stafford Horne:

 - Added support for restartable sequences (me)

 - Migration to Generic built-in DTB (Masahiro Yamada)

* tag 'for-linus' of https://github.com/openrisc/linux:
  rseq/selftests: Add support for OpenRISC
  openrisc: Add support for restartable sequences
  openrisc: Add HAVE_REGS_AND_STACK_ACCESS_API support
  openrisc: migrate to the generic rule for built-in DTB

Author: torvalds

arch/openrisc/Kbuild

@@ -1,6 +1,5 @@
 # SPDX-License-Identifier: GPL-2.0
 obj-y += lib/ kernel/ mm/
-obj-y += boot/dts/
 
 # for cleaning
 subdir- += boot

arch/openrisc/Kconfig

@@ -10,6 +10,7 @@ config OPENRISC
 	select ARCH_HAS_DMA_SET_UNCACHED
 	select ARCH_HAS_DMA_CLEAR_UNCACHED
 	select ARCH_HAS_SYNC_DMA_FOR_DEVICE
+	select GENERIC_BUILTIN_DTB
 	select COMMON_CLK
 	select OF
 	select OF_EARLY_FLATTREE
@@ -26,6 +27,8 @@ config OPENRISC
 	select HAVE_PCI
 	select HAVE_UID16
 	select HAVE_PAGE_SIZE_8KB
+	select HAVE_REGS_AND_STACK_ACCESS_API
+	select HAVE_RSEQ
 	select GENERIC_ATOMIC64
 	select GENERIC_CLOCKEVENTS_BROADCAST
 	select GENERIC_SMP_IDLE_THREAD
@@ -92,7 +95,7 @@ config DCACHE_WRITETHROUGH
 
 	  If unsure say N here
 
-config OPENRISC_BUILTIN_DTB
+config BUILTIN_DTB_NAME
 	string "Builtin DTB"
 	default ""
 

arch/openrisc/boot/dts/Makefile

@@ -1,4 +1,4 @@
 # SPDX-License-Identifier: GPL-2.0
-obj-y += $(addsuffix .dtb.o, $(CONFIG_OPENRISC_BUILTIN_DTB))
+dtb-y += $(addsuffix .dtb, $(CONFIG_BUILTIN_DTB_NAME))
 
 #DTC_FLAGS ?= -p 1024

arch/openrisc/configs/or1klitex_defconfig

@@ -7,7 +7,7 @@ CONFIG_BLK_DEV_INITRD=y
 CONFIG_CC_OPTIMIZE_FOR_SIZE=y
 CONFIG_SGETMASK_SYSCALL=y
 CONFIG_EXPERT=y
-CONFIG_OPENRISC_BUILTIN_DTB="or1klitex"
+CONFIG_BUILTIN_DTB_NAME="or1klitex"
 CONFIG_HZ_100=y
 CONFIG_OPENRISC_HAVE_SHADOW_GPRS=y
 CONFIG_NET=y

arch/openrisc/configs/or1ksim_defconfig

@@ -14,7 +14,7 @@ CONFIG_SLUB=y
 CONFIG_SLUB_TINY=y
 CONFIG_MODULES=y
 # CONFIG_BLOCK is not set
-CONFIG_OPENRISC_BUILTIN_DTB="or1ksim"
+CONFIG_BUILTIN_DTB_NAME="or1ksim"
 CONFIG_HZ_100=y
 CONFIG_NET=y
 CONFIG_PACKET=y

arch/openrisc/configs/simple_smp_defconfig

@@ -20,7 +20,7 @@ CONFIG_SLUB=y
 CONFIG_SLUB_TINY=y
 CONFIG_MODULES=y
 # CONFIG_BLOCK is not set
-CONFIG_OPENRISC_BUILTIN_DTB="simple_smp"
+CONFIG_BUILTIN_DTB_NAME="simple_smp"
 CONFIG_SMP=y
 CONFIG_HZ_100=y
 CONFIG_OPENRISC_HAVE_SHADOW_GPRS=y

arch/openrisc/include/asm/ptrace.h

@@ -17,6 +17,7 @@
 
 #include <asm/spr_defs.h>
 #include <uapi/asm/ptrace.h>
+#include <linux/compiler.h>
 
 /*
  * Make kernel PTrace/register structures opaque to userspace... userspace can
@@ -42,6 +43,36 @@ struct pt_regs {
 			/* Named registers */
 			long  sr;	/* Stored in place of r0 */
 			long  sp;	/* r1 */
+			long  gpr2;
+			long  gpr3;
+			long  gpr4;
+			long  gpr5;
+			long  gpr6;
+			long  gpr7;
+			long  gpr8;
+			long  gpr9;
+			long  gpr10;
+			long  gpr11;
+			long  gpr12;
+			long  gpr13;
+			long  gpr14;
+			long  gpr15;
+			long  gpr16;
+			long  gpr17;
+			long  gpr18;
+			long  gpr19;
+			long  gpr20;
+			long  gpr21;
+			long  gpr22;
+			long  gpr23;
+			long  gpr24;
+			long  gpr25;
+			long  gpr26;
+			long  gpr27;
+			long  gpr28;
+			long  gpr29;
+			long  gpr30;
+			long  gpr31;
 		};
 		struct {
 			/* Old style */
@@ -66,16 +97,56 @@ struct pt_regs {
 /* TODO: Rename this to REDZONE because that's what it is */
 #define STACK_FRAME_OVERHEAD  128  /* size of minimum stack frame */
 
-#define instruction_pointer(regs)	((regs)->pc)
+#define MAX_REG_OFFSET offsetof(struct pt_regs, orig_gpr11)
+
+/* Helpers for working with the instruction pointer */
+static inline unsigned long instruction_pointer(struct pt_regs *regs)
+{
+	return (unsigned long)regs->pc;
+}
+static inline void instruction_pointer_set(struct pt_regs *regs,
+					   unsigned long val)
+{
+	regs->pc = val;
+}
+
 #define user_mode(regs)			(((regs)->sr & SPR_SR_SM) == 0)
 #define user_stack_pointer(regs)	((unsigned long)(regs)->sp)
 #define profile_pc(regs)		instruction_pointer(regs)
 
+/* Valid only for Kernel mode traps. */
+static inline unsigned long kernel_stack_pointer(struct pt_regs *regs)
+{
+	return (unsigned long)regs->sp;
+}
+
 static inline long regs_return_value(struct pt_regs *regs)
 {
 	return regs->gpr[11];
 }
 
+extern int regs_query_register_offset(const char *name);
+extern unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs,
+					       unsigned int n);
+
+/**
+ * regs_get_register() - get register value from its offset
+ * @regs:	pt_regs from which register value is gotten
+ * @offset:	offset of the register.
+ *
+ * regs_get_register returns the value of a register whose offset from @regs.
+ * The @offset is the offset of the register in struct pt_regs.
+ * If @offset is bigger than MAX_REG_OFFSET, this returns 0.
+ */
+static inline unsigned long regs_get_register(struct pt_regs *regs,
+					      unsigned int offset)
+{
+	if (unlikely(offset > MAX_REG_OFFSET))
+		return 0;
+
+	return *(unsigned long *)((unsigned long)regs + offset);
+}
+
 #endif /* __ASSEMBLY__ */
 
 /*

arch/openrisc/kernel/entry.S

@@ -714,6 +714,10 @@ _syscall_check_trace_leave:
  * interrupts that set NEED_RESCHED or SIGNALPENDING... really true? */
 
 _syscall_check_work:
+#ifdef CONFIG_DEBUG_RSEQ
+	l.jal	rseq_syscall
+	 l.ori	r3,r1,0
+#endif
 	/* Here we need to disable interrupts */
 	DISABLE_INTERRUPTS(r27,r29)
 	TRACE_IRQS_OFF

arch/openrisc/kernel/ptrace.c

@@ -160,6 +160,102 @@ const struct user_regset_view *task_user_regset_view(struct task_struct *task)
  * in exit.c or in signal.c.
  */
 
+struct pt_regs_offset {
+	const char *name;
+	int offset;
+};
+
+#define REG_OFFSET_NAME(r) {.name = #r, .offset = offsetof(struct pt_regs, r)}
+#define REG_OFFSET_END {.name = NULL, .offset = 0}
+
+static const struct pt_regs_offset regoffset_table[] = {
+	REG_OFFSET_NAME(sr),
+	REG_OFFSET_NAME(sp),
+	REG_OFFSET_NAME(gpr2),
+	REG_OFFSET_NAME(gpr3),
+	REG_OFFSET_NAME(gpr4),
+	REG_OFFSET_NAME(gpr5),
+	REG_OFFSET_NAME(gpr6),
+	REG_OFFSET_NAME(gpr7),
+	REG_OFFSET_NAME(gpr8),
+	REG_OFFSET_NAME(gpr9),
+	REG_OFFSET_NAME(gpr10),
+	REG_OFFSET_NAME(gpr11),
+	REG_OFFSET_NAME(gpr12),
+	REG_OFFSET_NAME(gpr13),
+	REG_OFFSET_NAME(gpr14),
+	REG_OFFSET_NAME(gpr15),
+	REG_OFFSET_NAME(gpr16),
+	REG_OFFSET_NAME(gpr17),
+	REG_OFFSET_NAME(gpr18),
+	REG_OFFSET_NAME(gpr19),
+	REG_OFFSET_NAME(gpr20),
+	REG_OFFSET_NAME(gpr21),
+	REG_OFFSET_NAME(gpr22),
+	REG_OFFSET_NAME(gpr23),
+	REG_OFFSET_NAME(gpr24),
+	REG_OFFSET_NAME(gpr25),
+	REG_OFFSET_NAME(gpr26),
+	REG_OFFSET_NAME(gpr27),
+	REG_OFFSET_NAME(gpr28),
+	REG_OFFSET_NAME(gpr29),
+	REG_OFFSET_NAME(gpr30),
+	REG_OFFSET_NAME(gpr31),
+	REG_OFFSET_NAME(pc),
+	REG_OFFSET_NAME(orig_gpr11),
+	REG_OFFSET_END,
+};
+
+/**
+ * regs_query_register_offset() - query register offset from its name
+ * @name:	the name of a register
+ *
+ * regs_query_register_offset() returns the offset of a register in struct
+ * pt_regs from its name. If the name is invalid, this returns -EINVAL;
+ */
+int regs_query_register_offset(const char *name)
+{
+	const struct pt_regs_offset *roff;
+
+	for (roff = regoffset_table; roff->name != NULL; roff++)
+		if (!strcmp(roff->name, name))
+			return roff->offset;
+	return -EINVAL;
+}
+
+/**
+ * regs_within_kernel_stack() - check the address in the stack
+ * @regs:      pt_regs which contains kernel stack pointer.
+ * @addr:      address which is checked.
+ *
+ * regs_within_kernel_stack() checks @addr is within the kernel stack page(s).
+ * If @addr is within the kernel stack, it returns true. If not, returns false.
+ */
+static bool regs_within_kernel_stack(struct pt_regs *regs, unsigned long addr)
+{
+	return (addr & ~(THREAD_SIZE - 1))  ==
+		(kernel_stack_pointer(regs) & ~(THREAD_SIZE - 1));
+}
+
+/**
+ * regs_get_kernel_stack_nth() - get Nth entry of the stack
+ * @regs:	pt_regs which contains kernel stack pointer.
+ * @n:		stack entry number.
+ *
+ * regs_get_kernel_stack_nth() returns @n th entry of the kernel stack which
+ * is specified by @regs. If the @n th entry is NOT in the kernel stack,
+ * this returns 0.
+ */
+unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs, unsigned int n)
+{
+	unsigned long *addr = (unsigned long *)kernel_stack_pointer(regs);
+
+	addr += n;
+	if (regs_within_kernel_stack(regs, (unsigned long)addr))
+		return *addr;
+	else
+		return 0;
+}
 
 /*
  * Called by kernel/ptrace.c when detaching..

arch/openrisc/kernel/signal.c

@@ -244,6 +244,8 @@ handle_signal(struct ksignal *ksig, struct pt_regs *regs)
 {
 	int ret;
 
+	rseq_signal_deliver(ksig, regs);
+
 	ret = setup_rt_frame(ksig, sigmask_to_save(), regs);
 
 	signal_setup_done(ret, ksig, test_thread_flag(TIF_SINGLESTEP));