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  1. 18 11月, 2011 1 次提交
  3. 16 11月, 2011 1 次提交
    • D
      sparc: Stash orig_i0 into %g6 instead of %g2 · e88d2468
      由 David S. Miller 提交于 
      As per the comments added by this commit, %g2 turns out to not be a
usable place to save away orig_i0 for syscall restart handling.

In fact all of %g2, %g3, %g4, and %g5 are assumed to be saved across
a system call by various bits of code in glibc.

%g1 can't be used because that holds the syscall number, which would
need to be saved and restored for syscall restart handling too, and
that would only compound our problems :-)

This leaves us with %g6 and %g7 which are for "system use".  %g7 is
used as the "thread register" by glibc, but %g6 is used as a compiler
and assembler temporary scratch register.  And in no instance is %g6
used to hold a value across a system call.

Therefore %g6 is safe for storing away orig_i0, at least for now.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      e88d2468
  5. 15 11月, 2011 1 次提交
    • D
      sparc: Fix handling of orig_i0 wrt. debugging when restarting syscalls. · 1d299bc7
      由 David S. Miller 提交于 
      Although we provide a proper way for a debugger to control whether
syscall restart occurs, we run into problems because orig_i0 is not
saved and restored properly.

Luckily we can solve this problem without having to make debuggers
aware of the issue.  Across system calls, several registers are
considered volatile and can be safely clobbered.

Therefore we use the pt_regs save area of one of those registers, %g2,
as a place to save and restore orig_i0.

Debuggers transparently will do the right thing because they save and
restore this register already.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      1d299bc7
  7. 14 11月, 2011 2 次提交
  9. 13 11月, 2011 2 次提交
  11. 12 11月, 2011 17 次提交
  13. 11 11月, 2011 16 次提交