s390/perf: add perf_regs support and user stack dump

Add s390 support to dump user stack to user space for DWARF
stack unwinding.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Reviewed-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Reviewed-and-tested-by: Thomas Richter <tmricht@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig
index 8476704..829c679 100644 (file)
--- a/arch/s390/Kconfig
+++ b/arch/s390/Kconfig
@@ -159,6 +159,8 @@ config S390
        select HAVE_KRETPROBES
        select HAVE_KVM
        select HAVE_LIVEPATCH
+       select HAVE_PERF_REGS
+       select HAVE_PERF_USER_STACK_DUMP
        select HAVE_MEMBLOCK
        select HAVE_MEMBLOCK_NODE_MAP
        select HAVE_MEMBLOCK_PHYS_MAP

diff --git a/arch/s390/include/uapi/asm/perf_regs.h b/arch/s390/include/uapi/asm/perf_regs.h
new file mode 100644 (file)
index 0000000..f84ea6a
--- /dev/null
+++ b/arch/s390/include/uapi/asm/perf_regs.h
@@ -0,0 +1,27 @@
+#ifndef _ASM_S390_PERF_REGS_H
+#define _ASM_S390_PERF_REGS_H
+
+enum perf_event_s390_regs {
+       PERF_REG_S390_R0,
+       PERF_REG_S390_R1,
+       PERF_REG_S390_R2,
+       PERF_REG_S390_R3,
+       PERF_REG_S390_R4,
+       PERF_REG_S390_R5,
+       PERF_REG_S390_R6,
+       PERF_REG_S390_R7,
+       PERF_REG_S390_R8,
+       PERF_REG_S390_R9,
+       PERF_REG_S390_R10,
+       PERF_REG_S390_R11,
+       PERF_REG_S390_R12,
+       PERF_REG_S390_R13,
+       PERF_REG_S390_R14,
+       PERF_REG_S390_R15,
+       PERF_REG_S390_MASK,
+       PERF_REG_S390_PC,
+
+       PERF_REG_S390_MAX
+};
+
+#endif /* _ASM_S390_PERF_REGS_H */

diff --git a/arch/s390/kernel/Makefile b/arch/s390/kernel/Makefile
index 0319f4e..909bce6 100644 (file)
--- a/arch/s390/kernel/Makefile
+++ b/arch/s390/kernel/Makefile
@@ -79,7 +79,7 @@ obj-$(CONFIG_CRASH_DUMP)      += crash_dump.o
 obj-$(CONFIG_UPROBES)          += uprobes.o
 
 obj-$(CONFIG_PERF_EVENTS)      += perf_event.o perf_cpum_cf.o perf_cpum_sf.o
-obj-$(CONFIG_PERF_EVENTS)      += perf_cpum_cf_events.o
+obj-$(CONFIG_PERF_EVENTS)      += perf_cpum_cf_events.o perf_regs.o
 
 obj-$(CONFIG_TRACEPOINTS)      += trace.o
 

diff --git a/arch/s390/kernel/perf_regs.c b/arch/s390/kernel/perf_regs.c
new file mode 100644 (file)
index 0000000..e883e6a
--- /dev/null
+++ b/arch/s390/kernel/perf_regs.c
@@ -0,0 +1,49 @@
+#include <linux/perf_event.h>
+#include <linux/perf_regs.h>
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/bug.h>
+#include <asm/ptrace.h>
+
+u64 perf_reg_value(struct pt_regs *regs, int idx)
+{
+       if (WARN_ON_ONCE((u32)idx >= PERF_REG_S390_MAX))
+               return 0;
+
+       if (idx == PERF_REG_S390_MASK)
+               return regs->psw.mask;
+       if (idx == PERF_REG_S390_PC)
+               return regs->psw.addr;
+
+       return regs->gprs[idx];
+}
+
+#define REG_RESERVED (~((1UL << PERF_REG_S390_MAX) - 1))
+
+int perf_reg_validate(u64 mask)
+{
+       if (!mask || mask & REG_RESERVED)
+               return -EINVAL;
+
+       return 0;
+}
+
+u64 perf_reg_abi(struct task_struct *task)
+{
+       if (test_tsk_thread_flag(task, TIF_31BIT))
+               return PERF_SAMPLE_REGS_ABI_32;
+
+       return PERF_SAMPLE_REGS_ABI_64;
+}
+
+void perf_get_regs_user(struct perf_regs *regs_user,
+                       struct pt_regs *regs,
+                       struct pt_regs *regs_user_copy)
+{
+       /*
+        * Use the regs from the first interruption and let
+        * perf_sample_regs_intr() handle interrupts (regs == get_irq_regs()).
+        */
+       regs_user->regs = task_pt_regs(current);
+       regs_user->abi = perf_reg_abi(current);
+}