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path: root/arch/arc/kernel/ptrace.c
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2013-10-12ARC: Ignore ptrace SETREGSET request for synthetic register "stop_pc"Vineet Gupta
ARCompact TRAP_S insn used for breakpoints, commits before exception is taken (updating architectural PC). So ptregs->ret contains next-PC and not the breakpoint PC itself. This is different from other restartable exceptions such as TLB Miss where ptregs->ret has exact faulting PC. gdb needs to know exact-PC hence ARC ptrace GETREGSET provides for @stop_pc which returns ptregs->ret vs. EFA depending on the situation. However, writing stop_pc (SETREGSET request), which updates ptregs->ret doesn't makes sense stop_pc doesn't always correspond to that reg as described above. This was not an issue so far since user_regs->ret / user_regs->stop_pc had same value and both writing to ptregs->ret was OK, needless, but NOT broken, hence not observed. With gdb "jump", they diverge, and user_regs->ret updating ptregs is overwritten immediately with stop_pc, which this patch fixes. Reported-by: Anton Kolesov <akolesov@synopsys.com> Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-06-22ARC: pt_regs update #3: Remove unused gutter at start of callee_regsVineet Gupta
This is trickier than prev two: * context switching code saves kernel mode callee regs in the format of struct callee_regs thus needs adjustment. This also reduces the height of topmost kernel stack frame by 1 word. * Since kernel stack unwinder is sensitive to height of topmost kernel stack frame, that needs a word of adjustment too. ptrace needs a bit of updating since pt_regs now diverges from user_regs_struct. Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-06-22ARC: pt_regs update #2: Remove unused gutter at start of pt_regsVineet Gupta
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-02-15ARC: ptrace supportVineet Gupta
Signed-off-by: Vineet Gupta <vgupta@synopsys.com> Acked-by: Arnd Bergmann <arnd@arndb.de>
2013-02-15ARC: Last bits (stubs) to get to a running kernel with UARTVineet Gupta
This was part of port buildup strategy from Arnd to have a minimal kernel at first and then add optional features (stacktracing, ptrace, smp, kprobes, oprofile....) Signed-off-by: Vineet Gupta <vgupta@synopsys.com>