Le 26/11/2021 à 04:22, Nicholas Piggin a écrit :
Code patching tests patch the stack and (non-module) vmalloc space now,
which falls afoul of the new address check.
The stack patching can easily be fixed, but the vmalloc patching is more
difficult. For now, add an ugly workaround to skip the check while the
test code is running.
This really looks hacky.
To skip the test, you can call do_patch_instruction() instead of calling
patch_instruction().
Fixes: 8b8a8f0ab3f55 ("powerpc/code-patching: Improve verification of
patchability")
Signed-off-by: Nicholas Piggin <npig...@gmail.com>
---
arch/powerpc/lib/code-patching.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/arch/powerpc/lib/code-patching.c b/arch/powerpc/lib/code-patching.c
index 5e2fe133639e..57e160963ab7 100644
--- a/arch/powerpc/lib/code-patching.c
+++ b/arch/powerpc/lib/code-patching.c
@@ -187,10 +187,12 @@ static int do_patch_instruction(u32 *addr, struct
ppc_inst instr)
#endif /* CONFIG_STRICT_KERNEL_RWX */
+static bool skip_addr_verif = false;
+
int patch_instruction(u32 *addr, struct ppc_inst instr)
{
/* Make sure we aren't patching a freed init section */
- if (!kernel_text_address((unsigned long)addr))
+ if (!skip_addr_verif && !kernel_text_address((unsigned long)addr))
return 0;
return do_patch_instruction(addr, instr);
@@ -738,11 +740,13 @@ static int __init test_code_patching(void)
{
printk(KERN_DEBUG "Running code patching self-tests ...\n");
+ skip_addr_verif = true;
test_branch_iform();
test_branch_bform();
test_create_function_call();
test_translate_branch();
test_prefixed_patching();
+ skip_addr_verif = false;
return 0;
}
