diff options
| author | David S. Miller <davem@sunset.davemloft.net> | 2006-02-04 00:10:01 -0800 |
|---|---|---|
| committer | David S. Miller <davem@sunset.davemloft.net> | 2006-03-20 01:11:36 -0800 |
| commit | 314ef6859750b6539eac48d78059bb7986f29cb1 (patch) | |
| tree | 26c7da386349c1cf377225356e1012ae62da6f07 /arch/sparc64/kernel/process.c | |
| parent | ffe483d55229fadbaf4cc7316d47024a24ecd1a2 (diff) | |
[SPARC64]: Refine register window trap handling.
When saving and restoing trap state, do the window spill/fill
handling inline so that we never trap deeper than 2 trap levels.
This is important for chips like Niagara.
The window fixup code is massively simplified, and many more
improvements are now possible.
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'arch/sparc64/kernel/process.c')
| -rw-r--r-- | arch/sparc64/kernel/process.c | 20 |
1 files changed, 18 insertions, 2 deletions
diff --git a/arch/sparc64/kernel/process.c b/arch/sparc64/kernel/process.c index 26548fc604b6..803eea4dc4ff 100644 --- a/arch/sparc64/kernel/process.c +++ b/arch/sparc64/kernel/process.c @@ -541,6 +541,18 @@ void synchronize_user_stack(void) } } +static void stack_unaligned(unsigned long sp) +{ + siginfo_t info; + + info.si_signo = SIGBUS; + info.si_errno = 0; + info.si_code = BUS_ADRALN; + info.si_addr = (void __user *) sp; + info.si_trapno = 0; + force_sig_info(SIGBUS, &info, current); +} + void fault_in_user_windows(void) { struct thread_info *t = current_thread_info(); @@ -556,13 +568,17 @@ void fault_in_user_windows(void) flush_user_windows(); window = get_thread_wsaved(); - if (window != 0) { + if (likely(window != 0)) { window -= 1; do { unsigned long sp = (t->rwbuf_stkptrs[window] + bias); struct reg_window *rwin = &t->reg_window[window]; - if (copy_to_user((char __user *)sp, rwin, winsize)) + if (unlikely(sp & 0x7UL)) + stack_unaligned(sp); + + if (unlikely(copy_to_user((char __user *)sp, + rwin, winsize))) goto barf; } while (window--); } |