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| author | David S. Miller <davem@davemloft.net> | 2011-11-15 12:57:00 -0800 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2011-11-15 12:57:00 -0800 |
| commit | e88d2468718b0789b4c33da2f7e1cef2a1eee279 (patch) | |
| tree | beb5a9eff292f1faa05eb9b96b7f1bd7815da131 /arch/sparc/kernel/signal32.c | |
| parent | 1d299bc7732c34d85bd43ac1a8745f5a2fed2078 (diff) | |
| download | linux-e88d2468718b0789b4c33da2f7e1cef2a1eee279.tar.bz2 | |
sparc: Stash orig_i0 into %g6 instead of %g2
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: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'arch/sparc/kernel/signal32.c')
| -rw-r--r-- | arch/sparc/kernel/signal32.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/sparc/kernel/signal32.c b/arch/sparc/kernel/signal32.c index 2e86fd1ddc7b..023b8860dc97 100644 --- a/arch/sparc/kernel/signal32.c +++ b/arch/sparc/kernel/signal32.c @@ -837,7 +837,7 @@ void do_signal32(sigset_t *oldset, struct pt_regs * regs) if (pt_regs_is_syscall(regs) && (regs->tstate & (TSTATE_XCARRY | TSTATE_ICARRY))) { restart_syscall = 1; - orig_i0 = regs->u_regs[UREG_G2]; + orig_i0 = regs->u_regs[UREG_G6]; } if (signr > 0) { |