| 1 | |
| 2 | |
| 3 | * at the C-code level.
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| 4 | *
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| 5 | * Copyright (C) 1995 David S. Miller ([email protected])
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| 6 |
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| 7 |
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| 8 | #include <linux/kernel.h>
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| 9 | #include <linux/sched.h>
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| 10 | #include <linux/string.h>
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| 11 | #include <linux/mm.h>
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| 12 | #include <linux/smp.h>
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| 13 |
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| 14 | #include <asm/cacheflush.h>
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| 15 | #include <linux/uaccess.h>
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| 16 |
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| 17 | #include "kernel.h"
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| 18 |
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| 19 |
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| 20 | void flush_user_windows(void)
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| 21 | {
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| 22 | register int ctr asm("g5");
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| 23 |
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| 24 | ctr = 0;
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| 25 | __asm__ __volatile__(
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| 26 | "\n1:\n\t"
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| 27 | "ld [%%g6 + %2], %%g4\n\t"
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| 28 | "orcc %%g0, %%g4, %%g0\n\t"
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| 29 | "add %0, 1, %0\n\t"
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| 30 | "bne 1b\n\t"
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| 31 | " save %%sp, -64, %%sp\n"
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| 32 | "2:\n\t"
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| 33 | "subcc %0, 1, %0\n\t"
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| 34 | "bne 2b\n\t"
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| 35 | " restore %%g0, %%g0, %%g0\n"
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| 36 | : "=&r" (ctr)
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| 37 | : "0" (ctr),
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| 38 | "i" ((const unsigned long)TI_UWINMASK)
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| 39 | : "g4", "cc");
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| 40 | }
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| 41 |
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| 42 | static inline void shift_window_buffer(int first_win, int last_win, struct thread_info *tp)
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| 43 | {
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| 44 | int i;
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| 45 |
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| 46 | for(i = first_win; i < last_win; i++) {
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| 47 | tp->rwbuf_stkptrs[i] = tp->rwbuf_stkptrs[i+1];
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| 48 | memcpy(&tp->reg_window[i], &tp->reg_window[i+1], sizeof(struct reg_window32));
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| 49 | }
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| 50 | }
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| 51 |
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| 52 | |
| 53 | * on the stack that we can. Even if the %sp is unaligned
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| 54 | * we still copy the window there, the only case that we don't
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| 55 | * succeed is if the %sp points to a bum mapping altogether.
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| 56 | * setup_frame() and do_sigreturn() use this before shifting
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| 57 | * the user stack around. Future instruction and hardware
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| 58 | * bug workaround routines will need this functionality as
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| 59 | * well.
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| 60 |
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| 61 | void synchronize_user_stack(void)
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| 62 | {
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| 63 | struct thread_info *tp = current_thread_info();
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| 64 | int window;
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| 65 |
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| 66 | flush_user_windows();
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| 67 | if(!tp->w_saved)
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| 68 | return;
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| 69 |
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| 70 |
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| 71 | for(window = tp->w_saved - 1; window >= 0; window--) {
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| 72 | unsigned long sp = tp->rwbuf_stkptrs[window];
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| 73 |
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| 74 |
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| 75 | if (copy_to_user((char __user *) sp, &tp->reg_window[window],
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| 76 | sizeof(struct reg_window32)))
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| 77 | continue;
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| 78 |
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| 79 | shift_window_buffer(window, tp->w_saved - 1, tp);
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| 80 | tp->w_saved--;
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| 81 | }
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| 82 | }
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| 83 |
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| 84 | #if 0 |
| 85 | /* An optimization. */
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| 86 | static inline void copy_aligned_window(void *dest, const void *src)
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| 87 | {
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| 88 | __asm__ __volatile__("ldd [%1], %%g2\n\t"
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| 89 | "ldd [%1 + 0x8], %%g4\n\t"
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| 90 | "std %%g2, [%0]\n\t"
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| 91 | "std %%g4, [%0 + 0x8]\n\t"
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| 92 | "ldd [%1 + 0x10], %%g2\n\t"
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| 93 | "ldd [%1 + 0x18], %%g4\n\t"
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| 94 | "std %%g2, [%0 + 0x10]\n\t"
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| 95 | "std %%g4, [%0 + 0x18]\n\t"
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| 96 | "ldd [%1 + 0x20], %%g2\n\t"
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| 97 | "ldd [%1 + 0x28], %%g4\n\t"
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| 98 | "std %%g2, [%0 + 0x20]\n\t"
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| 99 | "std %%g4, [%0 + 0x28]\n\t"
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| 100 | "ldd [%1 + 0x30], %%g2\n\t"
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| 101 | "ldd [%1 + 0x38], %%g4\n\t"
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| 102 | "std %%g2, [%0 + 0x30]\n\t"
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| 103 | "std %%g4, [%0 + 0x38]\n\t" : :
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| 104 | "r" (dest), "r" (src) :
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| 105 | "g2", "g3", "g4", "g5");
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| 106 | }
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| 107 | #endif
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| 108 |
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| 109 | |
| 110 | * user stack. Unaligned %sp's are not allowed here.
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| 111 |
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| 112 |
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| 113 | void try_to_clear_window_buffer(struct pt_regs *regs, int who)
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| 114 | {
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| 115 | struct thread_info *tp = current_thread_info();
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| 116 | int window;
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| 117 |
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| 118 | flush_user_windows();
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| 119 | for(window = 0; window < tp->w_saved; window++) {
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| 120 | unsigned long sp = tp->rwbuf_stkptrs[window];
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| 121 |
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| 122 | if ((sp & 7) ||
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| 123 | copy_to_user((char __user *) sp, &tp->reg_window[window],
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| 124 | sizeof(struct reg_window32))) {
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| 125 | force_exit_sig(SIGILL);
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| 126 | return;
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| 127 | }
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| 128 | }
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| 129 | tp->w_saved = 0;
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| 130 | }
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