5b06fd3bb9
GCC can turn our static_call(name)(args...) into a tail call, in which case we get a JMP.d32 into the trampoline (which then does a further tail-call). Teach objtool to recognise and mark these in .static_call_sites and adjust the code patching to deal with this. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: https://lore.kernel.org/r/20200818135805.101186767@infradead.org
36 lines
1.1 KiB
C
36 lines
1.1 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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#ifndef _STATIC_CALL_TYPES_H
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#define _STATIC_CALL_TYPES_H
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#include <linux/types.h>
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#include <linux/stringify.h>
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#define STATIC_CALL_KEY_PREFIX __SCK__
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#define STATIC_CALL_KEY_PREFIX_STR __stringify(STATIC_CALL_KEY_PREFIX)
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#define STATIC_CALL_KEY_PREFIX_LEN (sizeof(STATIC_CALL_KEY_PREFIX_STR) - 1)
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#define STATIC_CALL_KEY(name) __PASTE(STATIC_CALL_KEY_PREFIX, name)
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#define STATIC_CALL_TRAMP_PREFIX __SCT__
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#define STATIC_CALL_TRAMP_PREFIX_STR __stringify(STATIC_CALL_TRAMP_PREFIX)
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#define STATIC_CALL_TRAMP_PREFIX_LEN (sizeof(STATIC_CALL_TRAMP_PREFIX_STR) - 1)
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#define STATIC_CALL_TRAMP(name) __PASTE(STATIC_CALL_TRAMP_PREFIX, name)
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#define STATIC_CALL_TRAMP_STR(name) __stringify(STATIC_CALL_TRAMP(name))
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/*
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* Flags in the low bits of static_call_site::key.
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*/
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#define STATIC_CALL_SITE_TAIL 1UL /* tail call */
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#define STATIC_CALL_SITE_INIT 2UL /* init section */
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#define STATIC_CALL_SITE_FLAGS 3UL
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/*
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* The static call site table needs to be created by external tooling (objtool
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* or a compiler plugin).
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*/
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struct static_call_site {
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s32 addr;
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s32 key;
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};
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#endif /* _STATIC_CALL_TYPES_H */
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