toracat / rpms / kernel

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diff -up linux-3.10.0-327.sdl7.x86_64/arch/x86/include/asm/ptrace.h.addmissing linux-3.10.0-327.sdl7.x86_64/arch/x86/include/asm/ptrace.h
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--- linux-3.10.0-327.sdl7.x86_64/arch/x86/include/asm/ptrace.h.addmissing	2015-10-29 16:56:51.000000000 -0400
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+++ linux-3.10.0-327.sdl7.x86_64/arch/x86/include/asm/ptrace.h	2015-11-21 23:33:16.430036291 -0500
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@@ -109,6 +109,23 @@ static inline int user_mode_vm(struct pt
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 #endif
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 }
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+/*
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+ * This is the fastest way to check whether regs come from user space.
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+ * It is unsafe if regs might come from vm86 mode, though -- in vm86
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+ * mode, all bits of CS and SS are completely under the user's control.
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+ * The CPU considers vm86 mode to be CPL 3 regardless of CS and SS.
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+ *
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+ * Do NOT use this function unless you have already ruled out the
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+ * possibility that regs came from vm86 mode.
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+ *
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+ * We check for RPL != 0 instead of RPL == 3 because we don't use rings
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+ * 1 or 2 and this is more efficient.
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+ */
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+static inline int user_mode_ignore_vm86(struct pt_regs *regs)
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+{
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+	return (regs->cs & SEGMENT_RPL_MASK) != 0;
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+}
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+
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 static inline int v8086_mode(struct pt_regs *regs)
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 {
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 #ifdef CONFIG_X86_32