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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:
Peter Zijlstra
2019-05-08 14:30:48 +02:00
cometido por Ingo Molnar
ascendente 5e1246ff2d
cometimento a9b3c6998d
3 ficheiros modificados com 49 adições e 31 eliminações

Ver ficheiro

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

Ver ficheiro

@@ -246,22 +246,6 @@
.Lend_\@:
.endm
/*
* This is a sneaky trick to help the unwinder find pt_regs on the stack. The
* frame pointer is replaced with an encoded pointer to pt_regs. The encoding
* is just clearing the MSB, which makes it an invalid stack address and is also
* a signal to the unwinder that it's a pt_regs pointer in disguise.
*
* NOTE: This macro must be used *after* SAVE_ALL because it corrupts the
* original rbp.
*/
.macro ENCODE_FRAME_POINTER
#ifdef CONFIG_FRAME_POINTER
mov %esp, %ebp
andl $0x7fffffff, %ebp
#endif
.endm
.macro RESTORE_INT_REGS
popl %ebx
popl %ecx