x86, traps, i386: factor out lazy io-bitmap copy
x86_64 does not do the lazy io-bitmap dance. Putting it in its own function makes i386's do_general_protection look much more like x86_64's. Signed-off-by: Alexander van Heukelum <heukelum@fastmail.fm> Signed-off-by: Ingo Molnar <mingo@elte.hu>
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a28680b4b8
Коммит
ae82157b3d
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@ -95,6 +95,47 @@ die_if_kernel(const char *str, struct pt_regs *regs, long err)
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die(str, regs, err);
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die(str, regs, err);
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}
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}
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/*
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* Perform the lazy TSS's I/O bitmap copy. If the TSS has an
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* invalid offset set (the LAZY one) and the faulting thread has
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* a valid I/O bitmap pointer, we copy the I/O bitmap in the TSS,
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* we set the offset field correctly and return 1.
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*/
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static int lazy_iobitmap_copy(void)
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{
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struct thread_struct *thread;
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struct tss_struct *tss;
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int cpu;
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cpu = get_cpu();
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tss = &per_cpu(init_tss, cpu);
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thread = ¤t->thread;
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if (tss->x86_tss.io_bitmap_base == INVALID_IO_BITMAP_OFFSET_LAZY &&
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thread->io_bitmap_ptr) {
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memcpy(tss->io_bitmap, thread->io_bitmap_ptr,
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thread->io_bitmap_max);
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/*
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* If the previously set map was extending to higher ports
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* than the current one, pad extra space with 0xff (no access).
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*/
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if (thread->io_bitmap_max < tss->io_bitmap_max) {
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memset((char *) tss->io_bitmap +
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thread->io_bitmap_max, 0xff,
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tss->io_bitmap_max - thread->io_bitmap_max);
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}
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tss->io_bitmap_max = thread->io_bitmap_max;
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tss->x86_tss.io_bitmap_base = IO_BITMAP_OFFSET;
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tss->io_bitmap_owner = thread;
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put_cpu();
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return 1;
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}
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put_cpu();
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return 0;
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}
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static void __kprobes
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static void __kprobes
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do_trap(int trapnr, int signr, char *str, struct pt_regs *regs,
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do_trap(int trapnr, int signr, char *str, struct pt_regs *regs,
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long error_code, siginfo_t *info)
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long error_code, siginfo_t *info)
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@ -187,44 +228,13 @@ void __kprobes
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do_general_protection(struct pt_regs *regs, long error_code)
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do_general_protection(struct pt_regs *regs, long error_code)
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{
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{
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struct task_struct *tsk;
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struct task_struct *tsk;
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struct thread_struct *thread;
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struct tss_struct *tss;
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int cpu;
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conditional_sti(regs);
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conditional_sti(regs);
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cpu = get_cpu();
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if (lazy_iobitmap_copy()) {
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tss = &per_cpu(init_tss, cpu);
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/* restart the faulting instruction */
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thread = ¤t->thread;
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/*
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* Perform the lazy TSS's I/O bitmap copy. If the TSS has an
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* invalid offset set (the LAZY one) and the faulting thread has
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* a valid I/O bitmap pointer, we copy the I/O bitmap in the TSS
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* and we set the offset field correctly. Then we let the CPU to
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* restart the faulting instruction.
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*/
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if (tss->x86_tss.io_bitmap_base == INVALID_IO_BITMAP_OFFSET_LAZY &&
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thread->io_bitmap_ptr) {
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memcpy(tss->io_bitmap, thread->io_bitmap_ptr,
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thread->io_bitmap_max);
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/*
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* If the previously set map was extending to higher ports
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* than the current one, pad extra space with 0xff (no access).
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*/
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if (thread->io_bitmap_max < tss->io_bitmap_max) {
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memset((char *) tss->io_bitmap +
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thread->io_bitmap_max, 0xff,
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tss->io_bitmap_max - thread->io_bitmap_max);
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}
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tss->io_bitmap_max = thread->io_bitmap_max;
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tss->x86_tss.io_bitmap_base = IO_BITMAP_OFFSET;
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tss->io_bitmap_owner = thread;
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put_cpu();
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return;
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return;
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}
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}
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put_cpu();
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if (regs->flags & X86_VM_MASK)
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if (regs->flags & X86_VM_MASK)
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goto gp_in_vm86;
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goto gp_in_vm86;
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