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From:   Christophe Leroy <christophe.leroy@csgroup.eu>
To:     Michael Ellerman <mpe@ellerman.id.au>,
        Nicholas Piggin <npiggin@gmail.com>, sv@linux.ibm.com,
        agust@denx.de, jpoimboe@kernel.org, peterz@infradead.org,
        jbaron@akamai.com, rostedt@goodmis.org, ardb@kernel.org,
        tglx@linutronix.de, mingo@redhat.com, bp@alien8.de,
        dave.hansen@linux.intel.com, hpa@zytor.com
Cc:     Christophe Leroy <christophe.leroy@csgroup.eu>,
        linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org,
        x86@kernel.org, chenzhongjin@huawei.com
Subject: [PATCH v2 6/7] static_call_inline: Provide trampoline address when updating sites
Date:   Fri,  8 Jul 2022 19:31:25 +0200
Message-Id: <5dbe60ab94ea25eb1c1fa08ac3a2d20e870c7969.1657301423.git.christophe.leroy@csgroup.eu>
In-Reply-To: <cover.1657301423.git.christophe.leroy@csgroup.eu>
References: <cover.1657301423.git.christophe.leroy@csgroup.eu>
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In preparation of support of inline static calls on powerpc, provide
trampoline address when updating sites, so that if the destination
function is too far for a direct function call, the call site will
be patched with a call to the trampoline.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/x86/kernel/static_call.c | 2 +-
 kernel/static_call_inline.c   | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/x86/kernel/static_call.c b/arch/x86/kernel/static_call.c
index aa72cefdd5be..4db30b0ea71c 100644
--- a/arch/x86/kernel/static_call.c
+++ b/arch/x86/kernel/static_call.c
@@ -102,7 +102,7 @@ void arch_static_call_transform(void *site, void *tramp, void *func, bool tail)
 {
 	mutex_lock(&text_mutex);
 
-	if (tramp) {
+	if (tramp && !site) {
 		__static_call_validate(tramp, true, true);
 		__static_call_transform(tramp, __sc_insn(!func, true), func);
 	}
diff --git a/kernel/static_call_inline.c b/kernel/static_call_inline.c
index dc5665b62814..b5de9d92fa4e 100644
--- a/kernel/static_call_inline.c
+++ b/kernel/static_call_inline.c
@@ -195,7 +195,7 @@ void __static_call_update(struct static_call_key *key, void *tramp, void *func)
 				continue;
 			}
 
-			arch_static_call_transform(site_addr, NULL, func,
+			arch_static_call_transform(site_addr, tramp, func,
 						   static_call_is_tail(site));
 		}
 	}
-- 
2.36.1