Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf

Daniel Borkmann says:

====================
pull-request: bpf 2017-12-06

The following pull-request contains BPF updates for your *net* tree.

The main changes are:

1) Fixing broken uapi for BPF tracing programs for s390 and arm64
   architectures due to pt_regs being in-kernel only, and not part
   of uapi right now. A wrapper is added that exports pt_regs in
   an asm-generic way. For arm64 this maps to existing user_pt_regs
   structure and for s390 a user_pt_regs structure exporting the
   beginning of pt_regs is added and uapi-exported, thus fixing the
   BPF issues seen in perf (and BPF selftests), all from Hendrik.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

3 files changed, 31 insertions, 3 deletions

diff --git a/tools/perf/arch/s390/Makefile b/tools/perf/arch/s390/Makefile
index 21322e0385b8..09ba923debe8 100644
--- a/tools/perf/arch/s390/Makefile
+++ b/tools/perf/arch/s390/Makefile
@@ -2,3 +2,4 @@ ifndef NO_DWARF
 PERF_HAVE_DWARF_REGS := 1
 endif
 HAVE_KVM_STAT_SUPPORT := 1
+PERF_HAVE_ARCH_REGS_QUERY_REGISTER_OFFSET := 1
diff --git a/tools/perf/arch/s390/util/dwarf-regs.c b/tools/perf/arch/s390/util/dwarf-regs.c
index f47576ce13ea..a8ace5cc6301 100644
--- a/tools/perf/arch/s390/util/dwarf-regs.c
+++ b/tools/perf/arch/s390/util/dwarf-regs.c
@@ -2,17 +2,43 @@
 /*
  * Mapping of DWARF debug register numbers into register names.
  *
- *    Copyright IBM Corp. 2010
- *    Author(s): Heiko Carstens <heiko.carstens@de.ibm.com>,
+ * Copyright IBM Corp. 2010, 2017
+ * Author(s): Heiko Carstens <heiko.carstens@de.ibm.com>,
+ *	      Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
  *
  */
 
+#include <errno.h>
 #include <stddef.h>
-#include <dwarf-regs.h>
+#include <stdlib.h>
 #include <linux/kernel.h>
+#include <asm/ptrace.h>
+#include <string.h>
+#include <dwarf-regs.h>
 #include "dwarf-regs-table.h"
 
 const char *get_arch_regstr(unsigned int n)
 {
 	return (n >= ARRAY_SIZE(s390_dwarf_regs)) ? NULL : s390_dwarf_regs[n];
 }
+
+/*
+ * Convert the register name into an offset to struct pt_regs (kernel).
+ * This is required by the BPF prologue generator.  The BPF
+ * program is called in the BPF overflow handler in the perf
+ * core.
+ */
+int regs_query_register_offset(const char *name)
+{
+	unsigned long gpr;
+
+	if (!name || strncmp(name, "%r", 2))
+		return -EINVAL;
+
+	errno = 0;
+	gpr = strtoul(name + 2, NULL, 10);
+	if (errno || gpr >= 16)
+		return -EINVAL;
+
+	return offsetof(user_pt_regs, gprs) + 8 * gpr;
+}
diff --git a/tools/perf/check-headers.sh b/tools/perf/check-headers.sh
index 77406d25e521..6db9d809fe97 100755
--- a/tools/perf/check-headers.sh
+++ b/tools/perf/check-headers.sh
@@ -30,6 +30,7 @@ arch/x86/include/uapi/asm/vmx.h
 arch/powerpc/include/uapi/asm/kvm.h
 arch/s390/include/uapi/asm/kvm.h
 arch/s390/include/uapi/asm/kvm_perf.h
+arch/s390/include/uapi/asm/ptrace.h
 arch/s390/include/uapi/asm/sie.h
 arch/arm/include/uapi/asm/kvm.h
 arch/arm64/include/uapi/asm/kvm.h