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| author | H.J. Lu <hjl.tools@gmail.com> | 2012-03-05 15:32:11 -0800 |
|---|---|---|
| committer | H. Peter Anvin <hpa@zytor.com> | 2012-03-05 15:43:45 -0800 |
| commit | 55283e2537714f9370c4ab847d170acf223daf90 (patch) | |
| tree | e20a2212d4de9d91c4b986a2a8dba5197516213e /arch/x86/include/asm/thread_info.h | |
| parent | e7084fd52ed71249ab2ce7a7d89d601c9d1f904c (diff) | |
x32: Add ptrace for x32
X32 ptrace is a hybrid of 64bit ptrace and compat ptrace with 32bit
address and longs. It use 64bit ptrace to access the full 64bit
registers. PTRACE_PEEKUSR and PTRACE_POKEUSR are only allowed to access
segment and debug registers. PTRACE_PEEKUSR returns the lower 32bits
and PTRACE_POKEUSR zero-extends 32bit value to 64bit. It works since
the upper 32bits of segment and debug registers of x32 process are always
zero. GDB only uses PTRACE_PEEKUSR and PTRACE_POKEUSR to access
segment and debug registers.
[ hpa: changed TIF_X32 test to use !is_ia32_task() instead, and moved
the system call number to the now-unused 521 slot. ]
Signed-off-by: "H.J. Lu" <hjl.tools@gmail.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Cc: Roland McGrath <roland@hack.frob.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Link: http://lkml.kernel.org/r/1329696488-16970-1-git-send-email-hpa@zytor.com
Diffstat (limited to 'arch/x86/include/asm/thread_info.h')
0 files changed, 0 insertions, 0 deletions