x86/stackframe: Move ENCODE_FRAME_POINTER to asm/frame.h
In preparation for wider use, move the ENCODE_FRAME_POINTER macros to a common header and provide inline asm versions. These macros are used to encode a pt_regs frame for the unwinder; see unwind_frame.c:decode_frame_pointer(). Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org>
Este cometimento está contido em:

cometido por
Ingo Molnar

ascendente
5e1246ff2d
cometimento
a9b3c6998d
@@ -172,21 +172,6 @@ For 32-bit we have the following conventions - kernel is built with
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.endif
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.endm
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/*
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* This is a sneaky trick to help the unwinder find pt_regs on the stack. The
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* frame pointer is replaced with an encoded pointer to pt_regs. The encoding
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* is just setting the LSB, which makes it an invalid stack address and is also
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* a signal to the unwinder that it's a pt_regs pointer in disguise.
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*
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* NOTE: This macro must be used *after* PUSH_AND_CLEAR_REGS because it corrupts
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* the original rbp.
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*/
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.macro ENCODE_FRAME_POINTER ptregs_offset=0
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#ifdef CONFIG_FRAME_POINTER
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leaq 1+\ptregs_offset(%rsp), %rbp
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#endif
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.endm
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#ifdef CONFIG_PAGE_TABLE_ISOLATION
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/*
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@@ -246,22 +246,6 @@
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.Lend_\@:
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.endm
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/*
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* This is a sneaky trick to help the unwinder find pt_regs on the stack. The
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* frame pointer is replaced with an encoded pointer to pt_regs. The encoding
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* is just clearing the MSB, which makes it an invalid stack address and is also
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* a signal to the unwinder that it's a pt_regs pointer in disguise.
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*
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* NOTE: This macro must be used *after* SAVE_ALL because it corrupts the
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* original rbp.
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*/
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.macro ENCODE_FRAME_POINTER
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#ifdef CONFIG_FRAME_POINTER
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mov %esp, %ebp
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andl $0x7fffffff, %ebp
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#endif
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.endm
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.macro RESTORE_INT_REGS
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popl %ebx
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popl %ecx
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