arm64: Better native ptrace support for compat tasks
authorCatalin Marinas <catalin.marinas@arm.com>
Tue, 14 Jul 2015 15:20:17 +0000 (16:20 +0100)
committerWill Deacon <will.deacon@arm.com>
Mon, 27 Jul 2015 10:08:39 +0000 (11:08 +0100)
commit5d220ff9420f8b1689805ba2d938bedf9e0860a4
treeea5dbe159882a9b54a8a2cbb957d8106d957e3a0
parent0723c05fb75e4428b79b5cd657af7496b2604422
arm64: Better native ptrace support for compat tasks

The compat ptrace interface allows access to the TLS register, hardware
breakpoints and watchpoints, syscall number. However, a native task
using the native ptrace interface to debug compat tasks (e.g. multi-arch
gdb) only has access to the general and VFP register sets. The compat
ptrace interface cannot be accessed from a native task.

This patch adds a new user_aarch32_ptrace_view which contains the TLS,
hardware breakpoint/watchpoint and syscall number regsets in addition to
the existing GPR and VFP regsets. This view is backwards compatible with
the previous kernels. Core dumping of 32-bit tasks and compat ptrace are
not affected since the original user_aarch32_view is preserved.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Reported-by: Yao Qi <yao.qi@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
arch/arm64/kernel/ptrace.c