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| author |  Peter Zijlstra <peterz@infradead.org>
| 2020-08-18 15:57:51 +0200 |
|---|---|---|
| committer |  Ingo Molnar <mingo@kernel.org>
| 2020-09-01 09:58:06 +0200 |
| commit | a945c8345ec0decb2f1a7f19a8c5e60bcb1dd1eb (patch) | |
| tree | 11d4ff482c11945ef30fe5c88493a2b49202ad27 /arch/x86/kernel/static_call.c | |
| parent | static_call: Add some validation (diff) | |
| download | linux-a945c8345ec0decb2f1a7f19a8c5e60bcb1dd1eb.tar.gz linux-a945c8345ec0decb2f1a7f19a8c5e60bcb1dd1eb.tar.bz2 linux-a945c8345ec0decb2f1a7f19a8c5e60bcb1dd1eb.zip | |
static_call: Allow early init
In order to use static_call() to wire up x86_pmu, we need to
initialize earlier, specifically before memory allocation works; copy
some of the tricks from jump_label to enable this.
Primarily we overload key->next to store a sites pointer when there
are no modules, this avoids having to use kmalloc() to initialize the
sites and allows us to run much earlier.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Link: https://lore.kernel.org/r/20200818135805.220737930@infradead.org
Diffstat (limited to 'arch/x86/kernel/static_call.c')
| -rw-r--r-- | arch/x86/kernel/static_call.c | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/arch/x86/kernel/static_call.c b/arch/x86/kernel/static_call.c index 55140d8db106..ca9a380d9c0b 100644 --- a/arch/x86/kernel/static_call.c +++ b/arch/x86/kernel/static_call.c @@ -11,7 +11,7 @@ enum insn_type { RET = 3, /* tramp / site cond-tail-call */ }; -static void __static_call_transform(void *insn, enum insn_type type, void *func) +static void __ref __static_call_transform(void *insn, enum insn_type type, void *func) { int size = CALL_INSN_SIZE; const void *code; @@ -38,6 +38,9 @@ static void __static_call_transform(void *insn, enum insn_type type, void *func) if (memcmp(insn, code, size) == 0) return; + if (unlikely(system_state == SYSTEM_BOOTING)) + return text_poke_early(insn, code, size); + text_poke_bp(insn, code, size, NULL); } |