forked from Minki/linux
d4bf7078c4
With CONFIG_FRAME_POINTER enabled, a thunk can pass a bad return address
value to the called function. '9*8(%rsp)' actually gets the frame
pointer, not the return address.
The only users of the 'put_ret_addr_in_rdi' option are two functions
which trace the enabling and disabling of interrupts, so this bug can
result in bad debug or tracing information with CONFIG_IRQSOFF_TRACER or
CONFIG_PROVE_LOCKING.
Fix this by implementing the suggestion of Linus: explicitly push
the frame pointer all the time and constify the stack offsets that
way. This is both correct and easier to read.
Reported-by: Matt Fleming <matt@codeblueprint.co.uk>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
[ Extended the changelog a bit. ]
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Alex Thorlton <athorlton@sgi.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Fixes: 058fb73274 ("x86/asm/entry: Create stack frames in thunk functions")
Link: http://lkml.kernel.org/r/20160517180606.v5o7wcgdni7443ol@treble
Signed-off-by: Ingo Molnar <mingo@kernel.org>
71 lines
1.5 KiB
ArmAsm
71 lines
1.5 KiB
ArmAsm
/*
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* Save registers before calling assembly functions. This avoids
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* disturbance of register allocation in some inline assembly constructs.
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* Copyright 2001,2002 by Andi Kleen, SuSE Labs.
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* Added trace_hardirqs callers - Copyright 2007 Steven Rostedt, Red Hat, Inc.
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* Subject to the GNU public license, v.2. No warranty of any kind.
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*/
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#include <linux/linkage.h>
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#include "calling.h"
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#include <asm/asm.h>
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/* rdi: arg1 ... normal C conventions. rax is saved/restored. */
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.macro THUNK name, func, put_ret_addr_in_rdi=0
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.globl \name
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.type \name, @function
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\name:
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pushq %rbp
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movq %rsp, %rbp
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pushq %rdi
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pushq %rsi
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pushq %rdx
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pushq %rcx
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pushq %rax
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pushq %r8
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pushq %r9
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pushq %r10
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pushq %r11
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.if \put_ret_addr_in_rdi
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/* 8(%rbp) is return addr on stack */
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movq 8(%rbp), %rdi
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.endif
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call \func
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jmp restore
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_ASM_NOKPROBE(\name)
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.endm
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#ifdef CONFIG_TRACE_IRQFLAGS
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THUNK trace_hardirqs_on_thunk,trace_hardirqs_on_caller,1
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THUNK trace_hardirqs_off_thunk,trace_hardirqs_off_caller,1
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#endif
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#ifdef CONFIG_DEBUG_LOCK_ALLOC
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THUNK lockdep_sys_exit_thunk,lockdep_sys_exit
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#endif
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#ifdef CONFIG_PREEMPT
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THUNK ___preempt_schedule, preempt_schedule
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THUNK ___preempt_schedule_notrace, preempt_schedule_notrace
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#endif
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#if defined(CONFIG_TRACE_IRQFLAGS) \
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|| defined(CONFIG_DEBUG_LOCK_ALLOC) \
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|| defined(CONFIG_PREEMPT)
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restore:
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popq %r11
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popq %r10
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popq %r9
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popq %r8
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popq %rax
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popq %rcx
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popq %rdx
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popq %rsi
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popq %rdi
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popq %rbp
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ret
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_ASM_NOKPROBE(restore)
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#endif
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