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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-08-07 13:18:06 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-08-07 13:18:06 +0000
commit638a9e433ecd61e64761352dbec1fa4f5874c941 (patch)
treefdbff74a238d7a5a7d1cef071b7230bc064b9f25 /arch/riscv/kernel/patch.c
parentReleasing progress-linux version 6.9.12-1~progress7.99u1. (diff)
downloadlinux-638a9e433ecd61e64761352dbec1fa4f5874c941.tar.xz
linux-638a9e433ecd61e64761352dbec1fa4f5874c941.zip
Merging upstream version 6.10.3.
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'arch/riscv/kernel/patch.c')
-rw-r--r--arch/riscv/kernel/patch.c39
1 files changed, 28 insertions, 11 deletions
diff --git a/arch/riscv/kernel/patch.c b/arch/riscv/kernel/patch.c
index 30e12b310c..ab03732d06 100644
--- a/arch/riscv/kernel/patch.c
+++ b/arch/riscv/kernel/patch.c
@@ -89,6 +89,14 @@ static int __patch_insn_set(void *addr, u8 c, size_t len)
memset(waddr, c, len);
+ /*
+ * We could have just patched a function that is about to be
+ * called so make sure we don't execute partially patched
+ * instructions by flushing the icache as soon as possible.
+ */
+ local_flush_icache_range((unsigned long)waddr,
+ (unsigned long)waddr + len);
+
patch_unmap(FIX_TEXT_POKE0);
if (across_pages)
@@ -135,6 +143,14 @@ static int __patch_insn_write(void *addr, const void *insn, size_t len)
ret = copy_to_kernel_nofault(waddr, insn, len);
+ /*
+ * We could have just patched a function that is about to be
+ * called so make sure we don't execute partially patched
+ * instructions by flushing the icache as soon as possible.
+ */
+ local_flush_icache_range((unsigned long)waddr,
+ (unsigned long)waddr + len);
+
patch_unmap(FIX_TEXT_POKE0);
if (across_pages)
@@ -189,14 +205,11 @@ int patch_text_set_nosync(void *addr, u8 c, size_t len)
ret = patch_insn_set(tp, c, len);
- if (!ret)
- flush_icache_range((uintptr_t)tp, (uintptr_t)tp + len);
-
return ret;
}
NOKPROBE_SYMBOL(patch_text_set_nosync);
-static int patch_insn_write(void *addr, const void *insn, size_t len)
+int patch_insn_write(void *addr, const void *insn, size_t len)
{
size_t patched = 0;
size_t size;
@@ -224,9 +237,6 @@ int patch_text_nosync(void *addr, const void *insns, size_t len)
ret = patch_insn_write(tp, insns, len);
- if (!ret)
- flush_icache_range((uintptr_t) tp, (uintptr_t) tp + len);
-
return ret;
}
NOKPROBE_SYMBOL(patch_text_nosync);
@@ -240,14 +250,21 @@ static int patch_text_cb(void *data)
if (atomic_inc_return(&patch->cpu_count) == num_online_cpus()) {
for (i = 0; ret == 0 && i < patch->ninsns; i++) {
len = GET_INSN_LENGTH(patch->insns[i]);
- ret = patch_text_nosync(patch->addr + i * len,
- &patch->insns[i], len);
+ ret = patch_insn_write(patch->addr + i * len, &patch->insns[i], len);
}
- atomic_inc(&patch->cpu_count);
+ /*
+ * Make sure the patching store is effective *before* we
+ * increment the counter which releases all waiting CPUs
+ * by using the release variant of atomic increment. The
+ * release pairs with the call to local_flush_icache_all()
+ * on the waiting CPU.
+ */
+ atomic_inc_return_release(&patch->cpu_count);
} else {
while (atomic_read(&patch->cpu_count) <= num_online_cpus())
cpu_relax();
- smp_mb();
+
+ local_flush_icache_all();
}
return ret;