mirror of https://github.com/Qortal/Brooklyn
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
130 lines
3.3 KiB
130 lines
3.3 KiB
// SPDX-License-Identifier: GPL-2.0 |
|
/* windows.c: Routines to deal with register window management |
|
* at the C-code level. |
|
* |
|
* Copyright (C) 1995 David S. Miller ([email protected]) |
|
*/ |
|
|
|
#include <linux/kernel.h> |
|
#include <linux/sched.h> |
|
#include <linux/string.h> |
|
#include <linux/mm.h> |
|
#include <linux/smp.h> |
|
|
|
#include <asm/cacheflush.h> |
|
#include <linux/uaccess.h> |
|
|
|
#include "kernel.h" |
|
|
|
/* Do save's until all user register windows are out of the cpu. */ |
|
void flush_user_windows(void) |
|
{ |
|
register int ctr asm("g5"); |
|
|
|
ctr = 0; |
|
__asm__ __volatile__( |
|
"\n1:\n\t" |
|
"ld [%%g6 + %2], %%g4\n\t" |
|
"orcc %%g0, %%g4, %%g0\n\t" |
|
"add %0, 1, %0\n\t" |
|
"bne 1b\n\t" |
|
" save %%sp, -64, %%sp\n" |
|
"2:\n\t" |
|
"subcc %0, 1, %0\n\t" |
|
"bne 2b\n\t" |
|
" restore %%g0, %%g0, %%g0\n" |
|
: "=&r" (ctr) |
|
: "0" (ctr), |
|
"i" ((const unsigned long)TI_UWINMASK) |
|
: "g4", "cc"); |
|
} |
|
|
|
static inline void shift_window_buffer(int first_win, int last_win, struct thread_info *tp) |
|
{ |
|
int i; |
|
|
|
for(i = first_win; i < last_win; i++) { |
|
tp->rwbuf_stkptrs[i] = tp->rwbuf_stkptrs[i+1]; |
|
memcpy(&tp->reg_window[i], &tp->reg_window[i+1], sizeof(struct reg_window32)); |
|
} |
|
} |
|
|
|
/* Place as many of the user's current register windows |
|
* on the stack that we can. Even if the %sp is unaligned |
|
* we still copy the window there, the only case that we don't |
|
* succeed is if the %sp points to a bum mapping altogether. |
|
* setup_frame() and do_sigreturn() use this before shifting |
|
* the user stack around. Future instruction and hardware |
|
* bug workaround routines will need this functionality as |
|
* well. |
|
*/ |
|
void synchronize_user_stack(void) |
|
{ |
|
struct thread_info *tp = current_thread_info(); |
|
int window; |
|
|
|
flush_user_windows(); |
|
if(!tp->w_saved) |
|
return; |
|
|
|
/* Ok, there is some dirty work to do. */ |
|
for(window = tp->w_saved - 1; window >= 0; window--) { |
|
unsigned long sp = tp->rwbuf_stkptrs[window]; |
|
|
|
/* Ok, let it rip. */ |
|
if (copy_to_user((char __user *) sp, &tp->reg_window[window], |
|
sizeof(struct reg_window32))) |
|
continue; |
|
|
|
shift_window_buffer(window, tp->w_saved - 1, tp); |
|
tp->w_saved--; |
|
} |
|
} |
|
|
|
#if 0 |
|
/* An optimization. */ |
|
static inline void copy_aligned_window(void *dest, const void *src) |
|
{ |
|
__asm__ __volatile__("ldd [%1], %%g2\n\t" |
|
"ldd [%1 + 0x8], %%g4\n\t" |
|
"std %%g2, [%0]\n\t" |
|
"std %%g4, [%0 + 0x8]\n\t" |
|
"ldd [%1 + 0x10], %%g2\n\t" |
|
"ldd [%1 + 0x18], %%g4\n\t" |
|
"std %%g2, [%0 + 0x10]\n\t" |
|
"std %%g4, [%0 + 0x18]\n\t" |
|
"ldd [%1 + 0x20], %%g2\n\t" |
|
"ldd [%1 + 0x28], %%g4\n\t" |
|
"std %%g2, [%0 + 0x20]\n\t" |
|
"std %%g4, [%0 + 0x28]\n\t" |
|
"ldd [%1 + 0x30], %%g2\n\t" |
|
"ldd [%1 + 0x38], %%g4\n\t" |
|
"std %%g2, [%0 + 0x30]\n\t" |
|
"std %%g4, [%0 + 0x38]\n\t" : : |
|
"r" (dest), "r" (src) : |
|
"g2", "g3", "g4", "g5"); |
|
} |
|
#endif |
|
|
|
/* Try to push the windows in a threads window buffer to the |
|
* user stack. Unaligned %sp's are not allowed here. |
|
*/ |
|
|
|
void try_to_clear_window_buffer(struct pt_regs *regs, int who) |
|
{ |
|
struct thread_info *tp = current_thread_info(); |
|
int window; |
|
|
|
flush_user_windows(); |
|
for(window = 0; window < tp->w_saved; window++) { |
|
unsigned long sp = tp->rwbuf_stkptrs[window]; |
|
|
|
if ((sp & 7) || |
|
copy_to_user((char __user *) sp, &tp->reg_window[window], |
|
sizeof(struct reg_window32))) { |
|
force_exit_sig(SIGILL); |
|
return; |
|
} |
|
} |
|
tp->w_saved = 0; |
|
}
|
|
|