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arm64: kprobe: protect/rename few definitions to be reused by uprobe

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decode-insn code has to be reused by arm64 uprobe implementation as well.
Therefore, this patch protects some portion of kprobe code and renames few
other, so that decode-insn functionality can be reused by uprobe even when
CONFIG_KPROBES is not defined.

kprobe_opcode_t and struct arch_specific_insn are also defined by
linux/kprobes.h, when CONFIG_KPROBES is not defined. So, protect these
definitions in asm/probes.h.

linux/kprobes.h already includes asm/kprobes.h. Therefore, remove inclusion
of asm/kprobes.h from decode-insn.c.

There are some definitions like kprobe_insn and kprobes_handler_t etc can
be re-used by uprobe. So, it would be better to remove 'k' from their
names.

struct arch_specific_insn is specific to kprobe. Therefore, introduce a new
struct arch_probe_insn which will be common for both kprobe and uprobe, so
that decode-insn code can be shared. Modify kprobe code accordingly.

Function arm_probe_decode_insn() will be needed by uprobe as well. So make
it global.

Signed-off-by: Pratyush Anand <panand@redhat.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
This commit is contained in:
Pratyush Anand 2016-11-02 14:40:41 +05:30 committed by Catalin Marinas
parent 1404d6f13e
commit c2249707ee
4 changed files with 52 additions and 43 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

19
arch/arm64/include/asm/probes.h
View File

@ -17,19 +17,22 @@
#include <asm/opcodes.h>
struct kprobe;
struct arch_specific_insn;
typedef u32 kprobe_opcode_t;
typedef void (kprobes_handler_t) (u32 opcode, long addr, struct pt_regs *);
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_specific_insn {
kprobe_opcode_t *insn;
struct arch_probe_insn {
probe_opcode_t *insn;
pstate_check_t *pstate_cc;
kprobes_handler_t *handler;
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;
};
#endif
#endif

32
arch/arm64/kernel/probes/decode-insn.c
View File

@ -78,8 +78,8 @@ static bool __kprobes aarch64_insn_is_steppable(u32 insn)
* INSN_GOOD If instruction is supported and uses instruction slot,
* INSN_GOOD_NO_SLOT If instruction is supported but doesn't use its slot.
*/
static enum kprobe_insn __kprobes
arm_probe_decode_insn(kprobe_opcode_t insn, struct arch_specific_insn *asi)
enum probe_insn __kprobes
arm_probe_decode_insn(probe_opcode_t insn, struct arch_probe_insn *api)
{
/*
* Instructions reading or modifying the PC won't work from the XOL
@ -89,26 +89,26 @@ arm_probe_decode_insn(kprobe_opcode_t insn, struct arch_specific_insn *asi)
return INSN_GOOD;
if (aarch64_insn_is_bcond(insn)) {
asi->handler = simulate_b_cond;
api->handler = simulate_b_cond;
} else if (aarch64_insn_is_cbz(insn) ||
aarch64_insn_is_cbnz(insn)) {
asi->handler = simulate_cbz_cbnz;
api->handler = simulate_cbz_cbnz;
} else if (aarch64_insn_is_tbz(insn) ||
aarch64_insn_is_tbnz(insn)) {
asi->handler = simulate_tbz_tbnz;
api->handler = simulate_tbz_tbnz;
} else if (aarch64_insn_is_adr_adrp(insn)) {
asi->handler = simulate_adr_adrp;
api->handler = simulate_adr_adrp;
} else if (aarch64_insn_is_b(insn) ||
aarch64_insn_is_bl(insn)) {
asi->handler = simulate_b_bl;
api->handler = simulate_b_bl;
} else if (aarch64_insn_is_br(insn) ||
aarch64_insn_is_blr(insn) ||
aarch64_insn_is_ret(insn)) {
asi->handler = simulate_br_blr_ret;
api->handler = simulate_br_blr_ret;
} else if (aarch64_insn_is_ldr_lit(insn)) {
asi->handler = simulate_ldr_literal;
api->handler = simulate_ldr_literal;
} else if (aarch64_insn_is_ldrsw_lit(insn)) {
asi->handler = simulate_ldrsw_literal;
api->handler = simulate_ldrsw_literal;
} else {
/*
* Instruction cannot be stepped out-of-line and we don't
@ -120,6 +120,7 @@ arm_probe_decode_insn(kprobe_opcode_t insn, struct arch_specific_insn *asi)
return INSN_GOOD_NO_SLOT;
}
#ifdef CONFIG_KPROBES
static bool __kprobes
is_probed_address_atomic(kprobe_opcode_t *scan_start, kprobe_opcode_t *scan_end)
{
@ -138,12 +139,12 @@ is_probed_address_atomic(kprobe_opcode_t *scan_start, kprobe_opcode_t *scan_end)
return false;
}
enum kprobe_insn __kprobes
enum probe_insn __kprobes
arm_kprobe_decode_insn(kprobe_opcode_t *addr, struct arch_specific_insn *asi)
{
enum kprobe_insn decoded;
kprobe_opcode_t insn = le32_to_cpu(*addr);
kprobe_opcode_t *scan_end = NULL;
enum probe_insn decoded;
probe_opcode_t insn = le32_to_cpu(*addr);
probe_opcode_t *scan_end = NULL;
unsigned long size = 0, offset = 0;
/*
@ -162,7 +163,7 @@ arm_kprobe_decode_insn(kprobe_opcode_t *addr, struct arch_specific_insn *asi)
else
scan_end = addr - MAX_ATOMIC_CONTEXT_SIZE;
}
decoded = arm_probe_decode_insn(insn, asi);
decoded = arm_probe_decode_insn(insn, &asi->api);
if (decoded != INSN_REJECTED && scan_end)
if (is_probed_address_atomic(addr - 1, scan_end))
@ -170,3 +171,4 @@ arm_kprobe_decode_insn(kprobe_opcode_t *addr, struct arch_specific_insn *asi)
return decoded;
}
#endif

8
arch/arm64/kernel/probes/decode-insn.h
View File

@ -23,13 +23,17 @@
*/
#define MAX_ATOMIC_CONTEXT_SIZE (128 / sizeof(kprobe_opcode_t))
enum kprobe_insn {
enum probe_insn {
INSN_REJECTED,
INSN_GOOD_NO_SLOT,
INSN_GOOD,
};
enum kprobe_insn __kprobes
#ifdef CONFIG_KPROBES
enum probe_insn __kprobes
arm_kprobe_decode_insn(kprobe_opcode_t *addr, struct arch_specific_insn *asi);
#endif
enum probe_insn __kprobes
arm_probe_decode_insn(probe_opcode_t insn, struct arch_probe_insn *asi);
#endif /* _ARM_KERNEL_KPROBES_ARM64_H */

36
arch/arm64/kernel/probes/kprobes.c
View File

@ -44,31 +44,31 @@ post_kprobe_handler(struct kprobe_ctlblk *, struct pt_regs *);
static void __kprobes arch_prepare_ss_slot(struct kprobe *p)
{
/* prepare insn slot */
p->ainsn.insn[0] = cpu_to_le32(p->opcode);
p->ainsn.api.insn[0] = cpu_to_le32(p->opcode);
flush_icache_range((uintptr_t) (p->ainsn.insn),
(uintptr_t) (p->ainsn.insn) +
flush_icache_range((uintptr_t) (p->ainsn.api.insn),
(uintptr_t) (p->ainsn.api.insn) +
MAX_INSN_SIZE * sizeof(kprobe_opcode_t));
/*
* Needs restoring of return address after stepping xol.
*/
p->ainsn.restore = (unsigned long) p->addr +
p->ainsn.api.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.restore = 0;
p->ainsn.api.restore = 0;
}
static void __kprobes arch_simulate_insn(struct kprobe *p, struct pt_regs *regs)
{
struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
if (p->ainsn.handler)
p->ainsn.handler((u32)p->opcode, (long)p->addr, regs);
if (p->ainsn.api.handler)
p->ainsn.api.handler((u32)p->opcode, (long)p->addr, regs);
/* single step simulated, now go for post processing */
post_kprobe_handler(kcb, regs);
@ -98,18 +98,18 @@ int __kprobes arch_prepare_kprobe(struct kprobe *p)
return -EINVAL;
case INSN_GOOD_NO_SLOT: /* insn need simulation */
p->ainsn.insn = NULL;
p->ainsn.api.insn = NULL;
break;
case INSN_GOOD: /* instruction uses slot */
p->ainsn.insn = get_insn_slot();
if (!p->ainsn.insn)
p->ainsn.api.insn = get_insn_slot();
if (!p->ainsn.api.insn)
return -ENOMEM;
break;
};
/* prepare the instruction */
if (p->ainsn.insn)
if (p->ainsn.api.insn)
arch_prepare_ss_slot(p);
else
arch_prepare_simulate(p);
@ -142,9 +142,9 @@ void __kprobes arch_disarm_kprobe(struct kprobe *p)
void __kprobes arch_remove_kprobe(struct kprobe *p)
{
if (p->ainsn.insn) {
free_insn_slot(p->ainsn.insn, 0);
p->ainsn.insn = NULL;
if (p->ainsn.api.insn) {
free_insn_slot(p->ainsn.api.insn, 0);
p->ainsn.api.insn = NULL;
}
}
@ -244,9 +244,9 @@ static void __kprobes setup_singlestep(struct kprobe *p,
}
if (p->ainsn.insn) {
if (p->ainsn.api.insn) {
/* prepare for single stepping */
slot = (unsigned long)p->ainsn.insn;
slot = (unsigned long)p->ainsn.api.insn;
set_ss_context(kcb, slot); /* mark pending ss */
@ -295,8 +295,8 @@ post_kprobe_handler(struct kprobe_ctlblk *kcb, struct pt_regs *regs)
return;
/* return addr restore if non-branching insn */
if (cur->ainsn.restore != 0)
instruction_pointer_set(regs, cur->ainsn.restore);
if (cur->ainsn.api.restore != 0)
instruction_pointer_set(regs, cur->ainsn.api.restore);
/* restore back original saved kprobe variables and continue */
if (kcb->kprobe_status == KPROBE_REENTER) {