From: Kees Cook <keescook@chromium.org>
Date: Fri, 27 Jan 2017 11:14:47 +0000 (+0000)
Subject: Fix PTRACE_GETREGSET failure for compat inferiors on arm64
X-Git-Tag: gdb-8.0-release~798
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=4bd2e1b2aee122b46e335d932f7833f9c86610d0;p=external%2Fbinutils.git

Fix PTRACE_GETREGSET failure for compat inferiors on arm64

When running a 32-bit ARM inferior with a 32-bit ARM GDB on a 64-bit
AArch64 host, only VFP registers (NT_ARM_VFP) are available. The FPA
registers (NT_PRFPREG) are not available so GDB must not request them, as
this will fail with -EINVAL.  This is most noticeably exposed when running
"generate-core-file":

(gdb) generate-core-file myprog.core
Unable to fetch the floating point registers.: Invalid argument.

ptrace(PTRACE_GETREGSET, 27642, NT_FPREGSET, 0xffcc67f0) = -1 EINVAL (Invalid argument)

gdb/ChangeLog:

2017-01-27  Kees Cook  <keescook@google.com>

	* gdb/arm-linux-nat.c (arm_linux_fetch_inferior_registers): Call
	fetch_fpregs if target has fpa registers.
	(arm_linux_store_inferior_registers): Call store_fpregs if target
	has fpa registers.
---

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index b7ce729..c146e0b 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,10 @@
+2017-01-27  Kees Cook  <keescook@google.com>
+
+	* gdb/arm-linux-nat.c (arm_linux_fetch_inferior_registers): Call
+	fetch_fpregs if target has fpa registers.
+	(arm_linux_store_inferior_registers): Call store_fpregs if target
+	has fpa registers.
+
 2017-01-26  Andreas Arnez  <arnez@linux.vnet.ibm.com>
 
 	* cris-tdep.c (cris_gdbarch_init): Remove check for
diff --git a/gdb/arm-linux-nat.c b/gdb/arm-linux-nat.c
index 3c48812..c8474a9 100644
--- a/gdb/arm-linux-nat.c
+++ b/gdb/arm-linux-nat.c
@@ -384,13 +384,14 @@ arm_linux_fetch_inferior_registers (struct target_ops *ops,
   if (-1 == regno)
     {
       fetch_regs (regcache);
-      fetch_fpregs (regcache);
       if (tdep->have_wmmx_registers)
 	fetch_wmmx_regs (regcache);
       if (tdep->vfp_register_count > 0)
 	fetch_vfp_regs (regcache);
+      if (tdep->have_fpa_registers)
+	fetch_fpregs (regcache);
     }
-  else 
+  else
     {
       if (regno < ARM_F0_REGNUM || regno == ARM_PS_REGNUM)
 	fetch_regs (regcache);
@@ -420,11 +421,12 @@ arm_linux_store_inferior_registers (struct target_ops *ops,
   if (-1 == regno)
     {
       store_regs (regcache);
-      store_fpregs (regcache);
       if (tdep->have_wmmx_registers)
 	store_wmmx_regs (regcache);
       if (tdep->vfp_register_count > 0)
 	store_vfp_regs (regcache);
+      if (tdep->have_fpa_registers)
+	store_fpregs (regcache);
     }
   else
     {