[PATCH v2 2/4] sparc64: kprobes: Fix up register and FP branches after single-step

[Stian Halseth <stian@itx.no>]

relbranch_fixup() moves the target of a PC-relative branch from the
single-step slot back to the probed instruction. It only knows call,
Bicc and BPcc. A taken BPr (brz, brnz, ...) or FBPfcc/FBfcc is left
alone. Execution resumes at the target relative to the slot:

  Unable to handle kernel paging request at virtual address 000000000fffff98
  TPC: <0xfffff98>

Treat them like the other PC-relative branches.

Link: https://github.com/sparclinux/issues/issues/110
Signed-off-by: Stian Halseth <stian@itx.no>
---
 arch/sparc/kernel/kprobes.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/arch/sparc/kernel/kprobes.c b/arch/sparc/kernel/kprobes.c
index 608efda8cb948..38e6d9b51a207 100644
--- a/arch/sparc/kernel/kprobes.c
+++ b/arch/sparc/kernel/kprobes.c
@@ -219,12 +219,15 @@ static unsigned long __kprobes relbranch_fixup(u32 insn, struct kprobe *p,
 	if (regs->tnpc == regs->tpc + 0x4UL)
 		return real_pc + 0x8UL;
 
-	/* The three cases are call, branch w/prediction,
-	 * and traditional branch.
+	/* The cases are call and the branches BPcc, Bicc, BPr, FBPfcc
+	 * and FBfcc.
 	 */
 	if ((insn & 0xc0000000) == 0x40000000 ||
 	    (insn & 0xc1c00000) == 0x00400000 ||
-	    (insn & 0xc1c00000) == 0x00800000) {
+	    (insn & 0xc1c00000) == 0x00800000 ||
+	    (insn & 0xc1c00000) == 0x00c00000 ||
+	    (insn & 0xc1c00000) == 0x01400000 ||
+	    (insn & 0xc1c00000) == 0x01800000) {
 		unsigned long ainsn_addr;
 
 		ainsn_addr = (unsigned long) &p->ainsn.insn[0];
-- 
2.43.0