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[PATCH] Fix PTRACE_GETREGSET failure for compat inferiors on arm64
- From: Kees Cook <keescook at chromium dot org>
- To: gdb-patches at sourceware dot org
- Cc: brian dot murray at canonical dot com, matthias dot klose at canonical dot com
- Date: Fri, 2 Dec 2016 13:46:13 -0800
- Subject: [PATCH] Fix PTRACE_GETREGSET failure for compat inferiors on arm64
- Authentication-results: sourceware.org; auth=none
When running a 32-bit ARM inferior on a 64-bit ARM host, only the hardware
floating-point registers (NT_ARM_VFP) are available. If the inferior
uses hard-float, do not request soft-float registers (NT_PRFPREG) and
run the risk of failing 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:
2016-12-02 Kees Cook <keescook@google.com>
* gdb/arm-linux-nat.c: Skip soft-float registers when using hard-float.
---
gdb/arm-linux-nat.c | 14 +++++++++-----
1 file changed, 9 insertions(+), 5 deletions(-)
diff --git a/gdb/arm-linux-nat.c b/gdb/arm-linux-nat.c
index d11bdc6..2126cd7 100644
--- a/gdb/arm-linux-nat.c
+++ b/gdb/arm-linux-nat.c
@@ -384,17 +384,19 @@ 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);
+ else
+ fetch_fpregs (regcache);
}
- else
+ else
{
if (regno < ARM_F0_REGNUM || regno == ARM_PS_REGNUM)
fetch_regs (regcache);
- else if (regno >= ARM_F0_REGNUM && regno <= ARM_FPS_REGNUM)
+ else if (tdep->vfp_register_count == 0
+ && regno >= ARM_F0_REGNUM && regno <= ARM_FPS_REGNUM)
fetch_fpregs (regcache);
else if (tdep->have_wmmx_registers
&& regno >= ARM_WR0_REGNUM && regno <= ARM_WCGR7_REGNUM)
@@ -420,17 +422,19 @@ 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);
+ else
+ store_fpregs (regcache);
}
else
{
if (regno < ARM_F0_REGNUM || regno == ARM_PS_REGNUM)
store_regs (regcache);
- else if ((regno >= ARM_F0_REGNUM) && (regno <= ARM_FPS_REGNUM))
+ else if (tdep->vfp_register_count == 0
+ && (regno >= ARM_F0_REGNUM) && (regno <= ARM_FPS_REGNUM))
store_fpregs (regcache);
else if (tdep->have_wmmx_registers
&& regno >= ARM_WR0_REGNUM && regno <= ARM_WCGR7_REGNUM)
--
2.7.4
--
Kees Cook
Nexus Security