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-rw-r--r--arch/x86/include/asm/insn.h10
-rw-r--r--arch/x86/kernel/cpu/perf_event_intel_ds.c17
-rw-r--r--arch/x86/kernel/cpu/perf_event_intel_lbr.c25
-rw-r--r--arch/x86/kernel/kprobes/core.c8
-rw-r--r--arch/x86/kernel/kprobes/opt.c4
-rw-r--r--arch/x86/kernel/uprobes.c2
-rw-r--r--arch/x86/lib/insn.c5
-rw-r--r--arch/x86/tools/insn_sanity.c2
-rw-r--r--arch/x86/tools/test_get_len.c2
9 files changed, 53 insertions, 22 deletions
diff --git a/arch/x86/include/asm/insn.h b/arch/x86/include/asm/insn.h
index 48eb30a..47f29b1 100644
--- a/arch/x86/include/asm/insn.h
+++ b/arch/x86/include/asm/insn.h
@@ -65,6 +65,7 @@ struct insn {
unsigned char x86_64;
const insn_byte_t *kaddr; /* kernel address of insn to analyze */
+ const insn_byte_t *end_kaddr; /* kernel address of last insn in buffer */
const insn_byte_t *next_byte;
};
@@ -96,7 +97,7 @@ struct insn {
#define X86_VEX_P(vex) ((vex) & 0x03) /* VEX3 Byte2, VEX2 Byte1 */
#define X86_VEX_M_MAX 0x1f /* VEX3.M Maximum value */
-extern void insn_init(struct insn *insn, const void *kaddr, int x86_64);
+extern void insn_init(struct insn *insn, const void *kaddr, int buf_len, int x86_64);
extern void insn_get_prefixes(struct insn *insn);
extern void insn_get_opcode(struct insn *insn);
extern void insn_get_modrm(struct insn *insn);
@@ -115,12 +116,13 @@ static inline void insn_get_attribute(struct insn *insn)
extern int insn_rip_relative(struct insn *insn);
/* Init insn for kernel text */
-static inline void kernel_insn_init(struct insn *insn, const void *kaddr)
+static inline void kernel_insn_init(struct insn *insn,
+ const void *kaddr, int buf_len)
{
#ifdef CONFIG_X86_64
- insn_init(insn, kaddr, 1);
+ insn_init(insn, kaddr, buf_len, 1);
#else /* CONFIG_X86_32 */
- insn_init(insn, kaddr, 0);
+ insn_init(insn, kaddr, buf_len, 0);
#endif
}
diff --git a/arch/x86/kernel/cpu/perf_event_intel_ds.c b/arch/x86/kernel/cpu/perf_event_intel_ds.c
index 46211bc..6a94277 100644
--- a/arch/x86/kernel/cpu/perf_event_intel_ds.c
+++ b/arch/x86/kernel/cpu/perf_event_intel_ds.c
@@ -724,6 +724,7 @@ static int intel_pmu_pebs_fixup_ip(struct pt_regs *regs)
unsigned long ip = regs->ip;
int is_64bit = 0;
void *kaddr;
+ int size;
/*
* We don't need to fixup if the PEBS assist is fault like
@@ -758,11 +759,12 @@ static int intel_pmu_pebs_fixup_ip(struct pt_regs *regs)
return 1;
}
+ size = ip - to;
if (!kernel_ip(ip)) {
- int size, bytes;
+ int bytes;
u8 *buf = this_cpu_read(insn_buffer);
- size = ip - to; /* Must fit our buffer, see above */
+ /* 'size' must fit our buffer, see above */
bytes = copy_from_user_nmi(buf, (void __user *)to, size);
if (bytes != 0)
return 0;
@@ -780,11 +782,20 @@ static int intel_pmu_pebs_fixup_ip(struct pt_regs *regs)
#ifdef CONFIG_X86_64
is_64bit = kernel_ip(to) || !test_thread_flag(TIF_IA32);
#endif
- insn_init(&insn, kaddr, is_64bit);
+ insn_init(&insn, kaddr, size, is_64bit);
insn_get_length(&insn);
+ /*
+ * Make sure there was not a problem decoding the
+ * instruction and getting the length. This is
+ * doubly important because we have an infinite
+ * loop if insn.length=0.
+ */
+ if (!insn.length)
+ break;
to += insn.length;
kaddr += insn.length;
+ size -= insn.length;
} while (to < ip);
if (to == ip) {
diff --git a/arch/x86/kernel/cpu/perf_event_intel_lbr.c b/arch/x86/kernel/cpu/perf_event_intel_lbr.c
index 45fa730..58f1a94 100644
--- a/arch/x86/kernel/cpu/perf_event_intel_lbr.c
+++ b/arch/x86/kernel/cpu/perf_event_intel_lbr.c
@@ -465,7 +465,7 @@ static int branch_type(unsigned long from, unsigned long to, int abort)
{
struct insn insn;
void *addr;
- int bytes, size = MAX_INSN_SIZE;
+ int bytes_read, bytes_left;
int ret = X86_BR_NONE;
int ext, to_plm, from_plm;
u8 buf[MAX_INSN_SIZE];
@@ -493,8 +493,10 @@ static int branch_type(unsigned long from, unsigned long to, int abort)
return X86_BR_NONE;
/* may fail if text not present */
- bytes = copy_from_user_nmi(buf, (void __user *)from, size);
- if (bytes != 0)
+ bytes_left = copy_from_user_nmi(buf, (void __user *)from,
+ MAX_INSN_SIZE);
+ bytes_read = MAX_INSN_SIZE - bytes_left;
+ if (!bytes_read)
return X86_BR_NONE;
addr = buf;
@@ -505,10 +507,19 @@ static int branch_type(unsigned long from, unsigned long to, int abort)
* Ensure we don't blindy read any address by validating it is
* a known text address.
*/
- if (kernel_text_address(from))
+ if (kernel_text_address(from)) {
addr = (void *)from;
- else
+ /*
+ * Assume we can get the maximum possible size
+ * when grabbing kernel data. This is not
+ * _strictly_ true since we could possibly be
+ * executing up next to a memory hole, but
+ * it is very unlikely to be a problem.
+ */
+ bytes_read = MAX_INSN_SIZE;
+ } else {
return X86_BR_NONE;
+ }
}
/*
@@ -518,8 +529,10 @@ static int branch_type(unsigned long from, unsigned long to, int abort)
#ifdef CONFIG_X86_64
is64 = kernel_ip((unsigned long)addr) || !test_thread_flag(TIF_IA32);
#endif
- insn_init(&insn, addr, is64);
+ insn_init(&insn, addr, bytes_read, is64);
insn_get_opcode(&insn);
+ if (!insn.opcode.got)
+ return X86_BR_ABORT;
switch (insn.opcode.bytes[0]) {
case 0xf:
diff --git a/arch/x86/kernel/kprobes/core.c b/arch/x86/kernel/kprobes/core.c
index 67e6d19e..f7e3cd5 100644
--- a/arch/x86/kernel/kprobes/core.c
+++ b/arch/x86/kernel/kprobes/core.c
@@ -285,7 +285,7 @@ static int can_probe(unsigned long paddr)
* normally used, we just go through if there is no kprobe.
*/
__addr = recover_probed_instruction(buf, addr);
- kernel_insn_init(&insn, (void *)__addr);
+ kernel_insn_init(&insn, (void *)__addr, MAX_INSN_SIZE);
insn_get_length(&insn);
/*
@@ -330,8 +330,10 @@ int __copy_instruction(u8 *dest, u8 *src)
{
struct insn insn;
kprobe_opcode_t buf[MAX_INSN_SIZE];
+ unsigned long recovered_insn =
+ recover_probed_instruction(buf, (unsigned long)src);
- kernel_insn_init(&insn, (void *)recover_probed_instruction(buf, (unsigned long)src));
+ kernel_insn_init(&insn, (void *)recovered_insn, MAX_INSN_SIZE);
insn_get_length(&insn);
/* Another subsystem puts a breakpoint, failed to recover */
if (insn.opcode.bytes[0] == BREAKPOINT_INSTRUCTION)
@@ -342,7 +344,7 @@ int __copy_instruction(u8 *dest, u8 *src)
if (insn_rip_relative(&insn)) {
s64 newdisp;
u8 *disp;
- kernel_insn_init(&insn, dest);
+ kernel_insn_init(&insn, dest, insn.length);
insn_get_displacement(&insn);
/*
* The copied instruction uses the %rip-relative addressing
diff --git a/arch/x86/kernel/kprobes/opt.c b/arch/x86/kernel/kprobes/opt.c
index f1314d0..7c523bb 100644
--- a/arch/x86/kernel/kprobes/opt.c
+++ b/arch/x86/kernel/kprobes/opt.c
@@ -251,13 +251,15 @@ static int can_optimize(unsigned long paddr)
/* Decode instructions */
addr = paddr - offset;
while (addr < paddr - offset + size) { /* Decode until function end */
+ unsigned long recovered_insn;
if (search_exception_tables(addr))
/*
* Since some fixup code will jumps into this function,
* we can't optimize kprobe in this function.
*/
return 0;
- kernel_insn_init(&insn, (void *)recover_probed_instruction(buf, addr));
+ recovered_insn = recover_probed_instruction(buf, addr);
+ kernel_insn_init(&insn, (void *)recovered_insn, MAX_INSN_SIZE);
insn_get_length(&insn);
/* Another subsystem puts a breakpoint */
if (insn.opcode.bytes[0] == BREAKPOINT_INSTRUCTION)
diff --git a/arch/x86/kernel/uprobes.c b/arch/x86/kernel/uprobes.c
index 5d1cbfe..8b96a94 100644
--- a/arch/x86/kernel/uprobes.c
+++ b/arch/x86/kernel/uprobes.c
@@ -219,7 +219,7 @@ static int uprobe_init_insn(struct arch_uprobe *auprobe, struct insn *insn, bool
{
u32 volatile *good_insns;
- insn_init(insn, auprobe->insn, x86_64);
+ insn_init(insn, auprobe->insn, sizeof(auprobe->insn), x86_64);
/* has the side-effect of processing the entire instruction */
insn_get_length(insn);
if (WARN_ON_ONCE(!insn_complete(insn)))
diff --git a/arch/x86/lib/insn.c b/arch/x86/lib/insn.c
index 54fcffe..2480978b 100644
--- a/arch/x86/lib/insn.c
+++ b/arch/x86/lib/insn.c
@@ -28,7 +28,7 @@
/* Verify next sizeof(t) bytes can be on the same instruction */
#define validate_next(t, insn, n) \
- ((insn)->next_byte + sizeof(t) + n - (insn)->kaddr <= MAX_INSN_SIZE)
+ ((insn)->next_byte + sizeof(t) + n < (insn)->end_kaddr)
#define __get_next(t, insn) \
({ t r = *(t*)insn->next_byte; insn->next_byte += sizeof(t); r; })
@@ -50,10 +50,11 @@
* @kaddr: address (in kernel memory) of instruction (or copy thereof)
* @x86_64: !0 for 64-bit kernel or 64-bit app
*/
-void insn_init(struct insn *insn, const void *kaddr, int x86_64)
+void insn_init(struct insn *insn, const void *kaddr, int buf_len, int x86_64)
{
memset(insn, 0, sizeof(*insn));
insn->kaddr = kaddr;
+ insn->end_kaddr = kaddr + buf_len;
insn->next_byte = kaddr;
insn->x86_64 = x86_64 ? 1 : 0;
insn->opnd_bytes = 4;
diff --git a/arch/x86/tools/insn_sanity.c b/arch/x86/tools/insn_sanity.c
index 872eb60..ba70ff2 100644
--- a/arch/x86/tools/insn_sanity.c
+++ b/arch/x86/tools/insn_sanity.c
@@ -254,7 +254,7 @@ int main(int argc, char **argv)
continue;
/* Decode an instruction */
- insn_init(&insn, insn_buf, x86_64);
+ insn_init(&insn, insn_buf, sizeof(insn_buf), x86_64);
insn_get_length(&insn);
if (insn.next_byte <= insn.kaddr ||
diff --git a/arch/x86/tools/test_get_len.c b/arch/x86/tools/test_get_len.c
index 13403fc..56f04db 100644
--- a/arch/x86/tools/test_get_len.c
+++ b/arch/x86/tools/test_get_len.c
@@ -149,7 +149,7 @@ int main(int argc, char **argv)
break;
}
/* Decode an instruction */
- insn_init(&insn, insn_buf, x86_64);
+ insn_init(&insn, insn_buf, sizeof(insn_buf), x86_64);
insn_get_length(&insn);
if (insn.length != nb) {
warnings++;
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