We share struct arch_probe_insn between krpboes and uprobes, but most of its fields aren't necessary for uprobes:
* The 'insn' field is only used by kprobes as a pointer to the XOL slot.
* The 'restore' field is only used by probes as the PC to restore after stepping an instruction in the XOL slot.
* The 'pstate_cc' field isn't used by kprobes or uprobes, and seems to only exist as a result of copy-pasting the 32-bit arm implementation of kprobes.
As these fields live in struct arch_probe_insn they cannot use definitions that only exist when CONFIG_KPROBES=y, such as the kprobe_opcode_t typedef, which we'd like to use in subsequent patches.
Clean this up by removing the 'pstate_cc' field, and moving the kprobes-specific fields into the kprobes-specific struct arch_specific_insn. To make it clear that the fields are related to stepping instructions in the XOL slot, 'insn' is renamed to 'xol_insn' and 'restore' is renamed to 'xol_restore'
At the same time, remove the misleading and useless comment above struct arch_probe_insn.
The should be no functional change as a result of this patch.
Signed-off-by: Mark Rutland mark.rutland@arm.com Cc: Catalin Marinas catalin.marinas@arm.com Cc: Will Deacon will@kernel.org --- arch/arm64/include/asm/probes.h | 8 +++----- arch/arm64/kernel/probes/kprobes.c | 30 +++++++++++++++--------------- 2 files changed, 18 insertions(+), 20 deletions(-)
diff --git a/arch/arm64/include/asm/probes.h b/arch/arm64/include/asm/probes.h index 006946745352e..4aa54322794da 100644 --- a/arch/arm64/include/asm/probes.h +++ b/arch/arm64/include/asm/probes.h @@ -12,18 +12,16 @@ typedef u32 probe_opcode_t; typedef void (probes_handler_t) (u32 opcode, long addr, struct pt_regs *);
-/* architecture specific copy of original instruction */ struct arch_probe_insn { - probe_opcode_t *insn; - pstate_check_t *pstate_cc; probes_handler_t *handler; - /* restore address after step xol */ - unsigned long restore; }; #ifdef CONFIG_KPROBES typedef u32 kprobe_opcode_t; struct arch_specific_insn { struct arch_probe_insn api; + probe_opcode_t *xol_insn; + /* restore address after step xol */ + unsigned long xol_restore; }; #endif
diff --git a/arch/arm64/kernel/probes/kprobes.c b/arch/arm64/kernel/probes/kprobes.c index 4268678d0e86c..222419a41a400 100644 --- a/arch/arm64/kernel/probes/kprobes.c +++ b/arch/arm64/kernel/probes/kprobes.c @@ -43,7 +43,7 @@ post_kprobe_handler(struct kprobe *, struct kprobe_ctlblk *, struct pt_regs *);
static void __kprobes arch_prepare_ss_slot(struct kprobe *p) { - kprobe_opcode_t *addr = p->ainsn.api.insn; + kprobe_opcode_t *addr = p->ainsn.xol_insn;
/* * Prepare insn slot, Mark Rutland points out it depends on a coupe of @@ -70,14 +70,14 @@ static void __kprobes arch_prepare_ss_slot(struct kprobe *p) /* * Needs restoring of return address after stepping xol. */ - p->ainsn.api.restore = (unsigned long) p->addr + + p->ainsn.xol_restore = (unsigned long) p->addr + sizeof(kprobe_opcode_t); }
static void __kprobes arch_prepare_simulate(struct kprobe *p) { /* This instructions is not executed xol. No need to adjust the PC */ - p->ainsn.api.restore = 0; + p->ainsn.xol_restore = 0; }
static void __kprobes arch_simulate_insn(struct kprobe *p, struct pt_regs *regs) @@ -110,18 +110,18 @@ int __kprobes arch_prepare_kprobe(struct kprobe *p) return -EINVAL;
case INSN_GOOD_NO_SLOT: /* insn need simulation */ - p->ainsn.api.insn = NULL; + p->ainsn.xol_insn = NULL; break;
case INSN_GOOD: /* instruction uses slot */ - p->ainsn.api.insn = get_insn_slot(); - if (!p->ainsn.api.insn) + p->ainsn.xol_insn = get_insn_slot(); + if (!p->ainsn.xol_insn) return -ENOMEM; break; }
/* prepare the instruction */ - if (p->ainsn.api.insn) + if (p->ainsn.xol_insn) arch_prepare_ss_slot(p); else arch_prepare_simulate(p); @@ -148,9 +148,9 @@ void __kprobes arch_disarm_kprobe(struct kprobe *p)
void __kprobes arch_remove_kprobe(struct kprobe *p) { - if (p->ainsn.api.insn) { - free_insn_slot(p->ainsn.api.insn, 0); - p->ainsn.api.insn = NULL; + if (p->ainsn.xol_insn) { + free_insn_slot(p->ainsn.xol_insn, 0); + p->ainsn.xol_insn = NULL; } }
@@ -205,9 +205,9 @@ static void __kprobes setup_singlestep(struct kprobe *p, }
- if (p->ainsn.api.insn) { + if (p->ainsn.xol_insn) { /* prepare for single stepping */ - slot = (unsigned long)p->ainsn.api.insn; + slot = (unsigned long)p->ainsn.xol_insn;
kprobes_save_local_irqflag(kcb, regs); instruction_pointer_set(regs, slot); @@ -245,8 +245,8 @@ static void __kprobes post_kprobe_handler(struct kprobe *cur, struct kprobe_ctlblk *kcb, struct pt_regs *regs) { /* return addr restore if non-branching insn */ - if (cur->ainsn.api.restore != 0) - instruction_pointer_set(regs, cur->ainsn.api.restore); + if (cur->ainsn.xol_restore != 0) + instruction_pointer_set(regs, cur->ainsn.xol_restore);
/* restore back original saved kprobe variables and continue */ if (kcb->kprobe_status == KPROBE_REENTER) { @@ -348,7 +348,7 @@ kprobe_breakpoint_ss_handler(struct pt_regs *regs, unsigned long esr) struct kprobe *cur = kprobe_running();
if (cur && (kcb->kprobe_status & (KPROBE_HIT_SS | KPROBE_REENTER)) && - ((unsigned long)&cur->ainsn.api.insn[1] == addr)) { + ((unsigned long)&cur->ainsn.xol_insn[1] == addr)) { kprobes_restore_local_irqflag(kcb, regs); post_kprobe_handler(cur, kcb, regs);