Re: [PATCH v7 20/28] powerpc: Make test_translate_branch() independent of instruction length
From: Alistair Popple <hidden>
Date: 2020-05-05 02:41:48
I guess this could change if there were prefixed branch instructions, but there aren't so: Reviewed-by: Alistair Popple <redacted> On Friday, 1 May 2020 1:42:12 PM AEST Jordan Niethe wrote:
quoted hunk ↗ jump to hunk
test_translate_branch() uses two pointers to instructions within a buffer, p and q, to test patch_branch(). The pointer arithmetic done on them assumes a size of 4. This will not work if the instruction length changes. Instead do the arithmetic relative to the void * to the buffer. Signed-off-by: Jordan Niethe <redacted> --- v4: New to series --- arch/powerpc/lib/code-patching.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-)diff --git a/arch/powerpc/lib/code-patching.cb/arch/powerpc/lib/code-patching.c index 110f710500c8..5b2f66d06b1e 100644--- a/arch/powerpc/lib/code-patching.c +++ b/arch/powerpc/lib/code-patching.c@@ -569,7 +569,7 @@ static void __init test_branch_bform(void) static void __init test_translate_branch(void) { unsigned long addr; - struct ppc_inst *p, *q; + void *p, *q; struct ppc_inst instr; void *buf;@@ -583,7 +583,7 @@ static void __init test_translate_branch(void) addr = (unsigned long)p; patch_branch(p, addr, 0); check(instr_is_branch_to_addr(p, addr)); - q = p + 1; + q = p + 4; translate_branch(&instr, q, p); patch_instruction(q, instr); check(instr_is_branch_to_addr(q, addr));@@ -639,7 +639,7 @@ static void __init test_translate_branch(void) create_cond_branch(&instr, p, addr, 0); patch_instruction(p, instr); check(instr_is_branch_to_addr(p, addr)); - q = p + 1; + q = buf + 4; translate_branch(&instr, q, p); patch_instruction(q, instr); check(instr_is_branch_to_addr(q, addr));