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-rw-r--r--arch/s390/include/asm/processor.h10
-rw-r--r--arch/s390/include/asm/switch_to.h4
-rw-r--r--arch/s390/include/uapi/asm/ptrace.h1
-rw-r--r--arch/s390/kernel/crash_dump.c51
-rw-r--r--arch/s390/kernel/ptrace.c50
-rw-r--r--arch/s390/net/bpf_jit_comp.c113
6 files changed, 186 insertions, 43 deletions
diff --git a/arch/s390/include/asm/processor.h b/arch/s390/include/asm/processor.h
index 6b499870662f..b0e6435b2f02 100644
--- a/arch/s390/include/asm/processor.h
+++ b/arch/s390/include/asm/processor.h
@@ -91,7 +91,15 @@ struct thread_struct {
#endif
};
-#define PER_FLAG_NO_TE 1UL /* Flag to disable transactions. */
+/* Flag to disable transactions. */
+#define PER_FLAG_NO_TE 1UL
+/* Flag to enable random transaction aborts. */
+#define PER_FLAG_TE_ABORT_RAND 2UL
+/* Flag to specify random transaction abort mode:
+ * - abort each transaction at a random instruction before TEND if set.
+ * - abort random transactions at a random instruction if cleared.
+ */
+#define PER_FLAG_TE_ABORT_RAND_TEND 4UL
typedef struct thread_struct thread_struct;
diff --git a/arch/s390/include/asm/switch_to.h b/arch/s390/include/asm/switch_to.h
index f3a9e0f92704..80b6f11263c4 100644
--- a/arch/s390/include/asm/switch_to.h
+++ b/arch/s390/include/asm/switch_to.h
@@ -10,7 +10,7 @@
#include <linux/thread_info.h>
extern struct task_struct *__switch_to(void *, void *);
-extern void update_per_regs(struct task_struct *task);
+extern void update_cr_regs(struct task_struct *task);
static inline void save_fp_regs(s390_fp_regs *fpregs)
{
@@ -86,7 +86,7 @@ static inline void restore_access_regs(unsigned int *acrs)
restore_fp_regs(&next->thread.fp_regs); \
restore_access_regs(&next->thread.acrs[0]); \
restore_ri_cb(next->thread.ri_cb, prev->thread.ri_cb); \
- update_per_regs(next); \
+ update_cr_regs(next); \
} \
prev = __switch_to(prev,next); \
} while (0)
diff --git a/arch/s390/include/uapi/asm/ptrace.h b/arch/s390/include/uapi/asm/ptrace.h
index 3aa9f1ec5b29..7a84619e315e 100644
--- a/arch/s390/include/uapi/asm/ptrace.h
+++ b/arch/s390/include/uapi/asm/ptrace.h
@@ -400,6 +400,7 @@ typedef struct
#define PTRACE_POKE_SYSTEM_CALL 0x5008
#define PTRACE_ENABLE_TE 0x5009
#define PTRACE_DISABLE_TE 0x5010
+#define PTRACE_TE_ABORT_RAND 0x5011
/*
* PT_PROT definition is loosely based on hppa bsd definition in
diff --git a/arch/s390/kernel/crash_dump.c b/arch/s390/kernel/crash_dump.c
index f703d91bf720..d8f355657171 100644
--- a/arch/s390/kernel/crash_dump.c
+++ b/arch/s390/kernel/crash_dump.c
@@ -21,6 +21,48 @@
#define PTR_SUB(x, y) (((char *) (x)) - ((unsigned long) (y)))
#define PTR_DIFF(x, y) ((unsigned long)(((char *) (x)) - ((unsigned long) (y))))
+
+/*
+ * Return physical address for virtual address
+ */
+static inline void *load_real_addr(void *addr)
+{
+ unsigned long real_addr;
+
+ asm volatile(
+ " lra %0,0(%1)\n"
+ " jz 0f\n"
+ " la %0,0\n"
+ "0:"
+ : "=a" (real_addr) : "a" (addr) : "cc");
+ return (void *)real_addr;
+}
+
+/*
+ * Copy up to one page to vmalloc or real memory
+ */
+static ssize_t copy_page_real(void *buf, void *src, size_t csize)
+{
+ size_t size;
+
+ if (is_vmalloc_addr(buf)) {
+ BUG_ON(csize >= PAGE_SIZE);
+ /* If buf is not page aligned, copy first part */
+ size = min(roundup(__pa(buf), PAGE_SIZE) - __pa(buf), csize);
+ if (size) {
+ if (memcpy_real(load_real_addr(buf), src, size))
+ return -EFAULT;
+ buf += size;
+ src += size;
+ }
+ /* Copy second part */
+ size = csize - size;
+ return (size) ? memcpy_real(load_real_addr(buf), src, size) : 0;
+ } else {
+ return memcpy_real(buf, src, csize);
+ }
+}
+
/*
* Copy one page from "oldmem"
*
@@ -32,6 +74,7 @@ ssize_t copy_oldmem_page(unsigned long pfn, char *buf,
size_t csize, unsigned long offset, int userbuf)
{
unsigned long src;
+ int rc;
if (!csize)
return 0;
@@ -43,11 +86,11 @@ ssize_t copy_oldmem_page(unsigned long pfn, char *buf,
src < OLDMEM_BASE + OLDMEM_SIZE)
src -= OLDMEM_BASE;
if (userbuf)
- copy_to_user_real((void __force __user *) buf, (void *) src,
- csize);
+ rc = copy_to_user_real((void __force __user *) buf,
+ (void *) src, csize);
else
- memcpy_real(buf, (void *) src, csize);
- return csize;
+ rc = copy_page_real(buf, (void *) src, csize);
+ return (rc == 0) ? csize : rc;
}
/*
diff --git a/arch/s390/kernel/ptrace.c b/arch/s390/kernel/ptrace.c
index a314c57f4e94..e9fadb04e3c6 100644
--- a/arch/s390/kernel/ptrace.c
+++ b/arch/s390/kernel/ptrace.c
@@ -47,7 +47,7 @@ enum s390_regset {
REGSET_GENERAL_EXTENDED,
};
-void update_per_regs(struct task_struct *task)
+void update_cr_regs(struct task_struct *task)
{
struct pt_regs *regs = task_pt_regs(task);
struct thread_struct *thread = &task->thread;
@@ -56,17 +56,25 @@ void update_per_regs(struct task_struct *task)
#ifdef CONFIG_64BIT
/* Take care of the enable/disable of transactional execution. */
if (MACHINE_HAS_TE) {
- unsigned long cr0, cr0_new;
+ unsigned long cr[3], cr_new[3];
- __ctl_store(cr0, 0, 0);
- /* set or clear transaction execution bits 8 and 9. */
+ __ctl_store(cr, 0, 2);
+ cr_new[1] = cr[1];
+ /* Set or clear transaction execution TXC/PIFO bits 8 and 9. */
if (task->thread.per_flags & PER_FLAG_NO_TE)
- cr0_new = cr0 & ~(3UL << 54);
+ cr_new[0] = cr[0] & ~(3UL << 54);
else
- cr0_new = cr0 | (3UL << 54);
- /* Only load control register 0 if necessary. */
- if (cr0 != cr0_new)
- __ctl_load(cr0_new, 0, 0);
+ cr_new[0] = cr[0] | (3UL << 54);
+ /* Set or clear transaction execution TDC bits 62 and 63. */
+ cr_new[2] = cr[2] & ~3UL;
+ if (task->thread.per_flags & PER_FLAG_TE_ABORT_RAND) {
+ if (task->thread.per_flags & PER_FLAG_TE_ABORT_RAND_TEND)
+ cr_new[2] |= 1UL;
+ else
+ cr_new[2] |= 2UL;
+ }
+ if (memcmp(&cr_new, &cr, sizeof(cr)))
+ __ctl_load(cr_new, 0, 2);
}
#endif
/* Copy user specified PER registers */
@@ -100,14 +108,14 @@ void user_enable_single_step(struct task_struct *task)
{
set_tsk_thread_flag(task, TIF_SINGLE_STEP);
if (task == current)
- update_per_regs(task);
+ update_cr_regs(task);
}
void user_disable_single_step(struct task_struct *task)
{
clear_tsk_thread_flag(task, TIF_SINGLE_STEP);
if (task == current)
- update_per_regs(task);
+ update_cr_regs(task);
}
/*
@@ -447,6 +455,26 @@ long arch_ptrace(struct task_struct *child, long request,
if (!MACHINE_HAS_TE)
return -EIO;
child->thread.per_flags |= PER_FLAG_NO_TE;
+ child->thread.per_flags &= ~PER_FLAG_TE_ABORT_RAND;
+ return 0;
+ case PTRACE_TE_ABORT_RAND:
+ if (!MACHINE_HAS_TE || (child->thread.per_flags & PER_FLAG_NO_TE))
+ return -EIO;
+ switch (data) {
+ case 0UL:
+ child->thread.per_flags &= ~PER_FLAG_TE_ABORT_RAND;
+ break;
+ case 1UL:
+ child->thread.per_flags |= PER_FLAG_TE_ABORT_RAND;
+ child->thread.per_flags |= PER_FLAG_TE_ABORT_RAND_TEND;
+ break;
+ case 2UL:
+ child->thread.per_flags |= PER_FLAG_TE_ABORT_RAND;
+ child->thread.per_flags &= ~PER_FLAG_TE_ABORT_RAND_TEND;
+ break;
+ default:
+ return -EINVAL;
+ }
return 0;
default:
/* Removing high order bit from addr (only for 31 bit). */
diff --git a/arch/s390/net/bpf_jit_comp.c b/arch/s390/net/bpf_jit_comp.c
index 82f165f8078c..d5f10a43a58f 100644
--- a/arch/s390/net/bpf_jit_comp.c
+++ b/arch/s390/net/bpf_jit_comp.c
@@ -9,6 +9,8 @@
#include <linux/netdevice.h>
#include <linux/if_vlan.h>
#include <linux/filter.h>
+#include <linux/random.h>
+#include <linux/init.h>
#include <asm/cacheflush.h>
#include <asm/processor.h>
#include <asm/facility.h>
@@ -221,6 +223,37 @@ static void bpf_jit_epilogue(struct bpf_jit *jit)
EMIT2(0x07fe);
}
+/* Helper to find the offset of pkt_type in sk_buff
+ * Make sure its still a 3bit field starting at the MSBs within a byte.
+ */
+#define PKT_TYPE_MAX 0xe0
+static int pkt_type_offset;
+
+static int __init bpf_pkt_type_offset_init(void)
+{
+ struct sk_buff skb_probe = {
+ .pkt_type = ~0,
+ };
+ char *ct = (char *)&skb_probe;
+ int off;
+
+ pkt_type_offset = -1;
+ for (off = 0; off < sizeof(struct sk_buff); off++) {
+ if (!ct[off])
+ continue;
+ if (ct[off] == PKT_TYPE_MAX)
+ pkt_type_offset = off;
+ else {
+ /* Found non matching bit pattern, fix needed. */
+ WARN_ON_ONCE(1);
+ pkt_type_offset = -1;
+ return -1;
+ }
+ }
+ return 0;
+}
+device_initcall(bpf_pkt_type_offset_init);
+
/*
* make sure we dont leak kernel information to user
*/
@@ -720,6 +753,16 @@ call_fn: /* lg %r1,<d(function)>(%r13) */
EMIT4_DISP(0x88500000, 12);
}
break;
+ case BPF_S_ANC_PKTTYPE:
+ if (pkt_type_offset < 0)
+ goto out;
+ /* lhi %r5,0 */
+ EMIT4(0xa7580000);
+ /* ic %r5,<d(pkt_type_offset)>(%r2) */
+ EMIT4_DISP(0x43502000, pkt_type_offset);
+ /* srl %r5,5 */
+ EMIT4_DISP(0x88500000, 5);
+ break;
case BPF_S_ANC_CPU: /* A = smp_processor_id() */
#ifdef CONFIG_SMP
/* l %r5,<d(cpu_nr)> */
@@ -738,8 +781,41 @@ out:
return -1;
}
+/*
+ * Note: for security reasons, bpf code will follow a randomly
+ * sized amount of illegal instructions.
+ */
+struct bpf_binary_header {
+ unsigned int pages;
+ u8 image[];
+};
+
+static struct bpf_binary_header *bpf_alloc_binary(unsigned int bpfsize,
+ u8 **image_ptr)
+{
+ struct bpf_binary_header *header;
+ unsigned int sz, hole;
+
+ /* Most BPF filters are really small, but if some of them fill a page,
+ * allow at least 128 extra bytes for illegal instructions.
+ */
+ sz = round_up(bpfsize + sizeof(*header) + 128, PAGE_SIZE);
+ header = module_alloc(sz);
+ if (!header)
+ return NULL;
+ memset(header, 0, sz);
+ header->pages = sz / PAGE_SIZE;
+ hole = sz - bpfsize + sizeof(*header);
+ /* Insert random number of illegal instructions before BPF code
+ * and make sure the first instruction starts at an even address.
+ */
+ *image_ptr = &header->image[(prandom_u32() % hole) & -2];
+ return header;
+}
+
void bpf_jit_compile(struct sk_filter *fp)
{
+ struct bpf_binary_header *header = NULL;
unsigned long size, prg_len, lit_len;
struct bpf_jit jit, cjit;
unsigned int *addrs;
@@ -772,12 +848,11 @@ void bpf_jit_compile(struct sk_filter *fp)
} else if (jit.prg == cjit.prg && jit.lit == cjit.lit) {
prg_len = jit.prg - jit.start;
lit_len = jit.lit - jit.mid;
- size = max_t(unsigned long, prg_len + lit_len,
- sizeof(struct work_struct));
+ size = prg_len + lit_len;
if (size >= BPF_SIZE_MAX)
goto out;
- jit.start = module_alloc(size);
- if (!jit.start)
+ header = bpf_alloc_binary(size, &jit.start);
+ if (!header)
goto out;
jit.prg = jit.mid = jit.start + prg_len;
jit.lit = jit.end = jit.start + prg_len + lit_len;
@@ -788,37 +863,25 @@ void bpf_jit_compile(struct sk_filter *fp)
cjit = jit;
}
if (bpf_jit_enable > 1) {
- pr_err("flen=%d proglen=%lu pass=%d image=%p\n",
- fp->len, jit.end - jit.start, pass, jit.start);
- if (jit.start) {
- printk(KERN_ERR "JIT code:\n");
+ bpf_jit_dump(fp->len, jit.end - jit.start, pass, jit.start);
+ if (jit.start)
print_fn_code(jit.start, jit.mid - jit.start);
- print_hex_dump(KERN_ERR, "JIT literals:\n",
- DUMP_PREFIX_ADDRESS, 16, 1,
- jit.mid, jit.end - jit.mid, false);
- }
}
- if (jit.start)
+ if (jit.start) {
+ set_memory_ro((unsigned long)header, header->pages);
fp->bpf_func = (void *) jit.start;
+ }
out:
kfree(addrs);
}
-static void jit_free_defer(struct work_struct *arg)
-{
- module_free(NULL, arg);
-}
-
-/* run from softirq, we must use a work_struct to call
- * module_free() from process context
- */
void bpf_jit_free(struct sk_filter *fp)
{
- struct work_struct *work;
+ unsigned long addr = (unsigned long)fp->bpf_func & PAGE_MASK;
+ struct bpf_binary_header *header = (void *)addr;
if (fp->bpf_func == sk_run_filter)
return;
- work = (struct work_struct *)fp->bpf_func;
- INIT_WORK(work, jit_free_defer);
- schedule_work(work);
+ set_memory_rw(addr, header->pages);
+ module_free(NULL, header);
}
generated by cgit v1.2.3 (git 2.0.4) at 2024-11-15 09:33:53 +0000