diff options
| author | Peter Zijlstra <peterz@infradead.org> | 2020-08-18 15:57:49 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2020-09-01 09:58:06 +0200 |
| commit | 5b06fd3bb9cdce4f3e731c48eb5b74c4acc47997 (patch) | |
| tree | 533fcad5bdd98fd31ccd3956dec2e3478f15ca91 /tools/include/linux | |
| parent | 452cddbff74b6a15b9354505671011700fe03710 (diff) | |
static_call: Handle tail-calls
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
Diffstat (limited to 'tools/include/linux')
| -rw-r--r-- | tools/include/linux/static_call_types.h | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/tools/include/linux/static_call_types.h b/tools/include/linux/static_call_types.h index 408d345d83e1..89135bb35bf7 100644 --- a/tools/include/linux/static_call_types.h +++ b/tools/include/linux/static_call_types.h @@ -17,6 +17,13 @@ #define STATIC_CALL_TRAMP_STR(name) __stringify(STATIC_CALL_TRAMP(name)) /* + * Flags in the low bits of static_call_site::key. + */ +#define STATIC_CALL_SITE_TAIL 1UL /* tail call */ +#define STATIC_CALL_SITE_INIT 2UL /* init section */ +#define STATIC_CALL_SITE_FLAGS 3UL + +/* * The static call site table needs to be created by external tooling (objtool * or a compiler plugin). */ |