Merge branch 'fixes' of git://git.armlinux.org.uk/~rmk/linux-arm

Pull ARM fixes from Russell King:
 "A number of ARM fixes:

   - prevent oopses caused by dma_get_sgtable() and declared DMA
     coherent memory

   - fix boot failure on nommu caused by ID_PFR1 access

   - a number of kprobes fixes from Jon Medhurst and Masami Hiramatsu"

* 'fixes' of git://git.armlinux.org.uk/~rmk/linux-arm:
  ARM: 8665/1: nommu: access ID_PFR1 only if CPUID scheme
  ARM: dma-mapping: disallow dma_get_sgtable() for non-kernel managed memory
  arm: kprobes: Align stack to 8-bytes in test code
  arm: kprobes: Fix the return address of multiple kretprobes
  arm: kprobes: Skip single-stepping in recursing path if possible
  arm: kprobes: Allow to handle reentered kprobe on single-stepping
This commit is contained in:
Linus Torvalds 2017-04-09 09:05:25 -07:00
commit 462e9a355e
4 changed files with 75 additions and 22 deletions

View File

@ -935,13 +935,31 @@ static void arm_coherent_dma_free(struct device *dev, size_t size, void *cpu_add
__arm_dma_free(dev, size, cpu_addr, handle, attrs, true);
}
/*
* The whole dma_get_sgtable() idea is fundamentally unsafe - it seems
* that the intention is to allow exporting memory allocated via the
* coherent DMA APIs through the dma_buf API, which only accepts a
* scattertable. This presents a couple of problems:
* 1. Not all memory allocated via the coherent DMA APIs is backed by
* a struct page
* 2. Passing coherent DMA memory into the streaming APIs is not allowed
* as we will try to flush the memory through a different alias to that
* actually being used (and the flushes are redundant.)
*/
int arm_dma_get_sgtable(struct device *dev, struct sg_table *sgt,
void *cpu_addr, dma_addr_t handle, size_t size,
unsigned long attrs)
{
struct page *page = pfn_to_page(dma_to_pfn(dev, handle));
unsigned long pfn = dma_to_pfn(dev, handle);
struct page *page;
int ret;
/* If the PFN is not valid, we do not have a struct page */
if (!pfn_valid(pfn))
return -ENXIO;
page = pfn_to_page(pfn);
ret = sg_alloc_table(sgt, 1, GFP_KERNEL);
if (unlikely(ret))
return ret;

View File

@ -303,7 +303,10 @@ static inline void set_vbar(unsigned long val)
*/
static inline bool security_extensions_enabled(void)
{
return !!cpuid_feature_extract(CPUID_EXT_PFR1, 4);
/* Check CPUID Identification Scheme before ID_PFR1 read */
if ((read_cpuid_id() & 0x000f0000) == 0x000f0000)
return !!cpuid_feature_extract(CPUID_EXT_PFR1, 4);
return 0;
}
static unsigned long __init setup_vectors_base(void)

View File

@ -266,11 +266,20 @@ void __kprobes kprobe_handler(struct pt_regs *regs)
#endif
if (p) {
if (cur) {
if (!p->ainsn.insn_check_cc(regs->ARM_cpsr)) {
/*
* Probe hit but conditional execution check failed,
* so just skip the instruction and continue as if
* nothing had happened.
* In this case, we can skip recursing check too.
*/
singlestep_skip(p, regs);
} else if (cur) {
/* Kprobe is pending, so we're recursing. */
switch (kcb->kprobe_status) {
case KPROBE_HIT_ACTIVE:
case KPROBE_HIT_SSDONE:
case KPROBE_HIT_SS:
/* A pre- or post-handler probe got us here. */
kprobes_inc_nmissed_count(p);
save_previous_kprobe(kcb);
@ -279,11 +288,16 @@ void __kprobes kprobe_handler(struct pt_regs *regs)
singlestep(p, regs, kcb);
restore_previous_kprobe(kcb);
break;
case KPROBE_REENTER:
/* A nested probe was hit in FIQ, it is a BUG */
pr_warn("Unrecoverable kprobe detected at %p.\n",
p->addr);
/* fall through */
default:
/* impossible cases */
BUG();
}
} else if (p->ainsn.insn_check_cc(regs->ARM_cpsr)) {
} else {
/* Probe hit and conditional execution check ok. */
set_current_kprobe(p);
kcb->kprobe_status = KPROBE_HIT_ACTIVE;
@ -304,13 +318,6 @@ void __kprobes kprobe_handler(struct pt_regs *regs)
}
reset_current_kprobe();
}
} else {
/*
* Probe hit but conditional execution check failed,
* so just skip the instruction and continue as if
* nothing had happened.
*/
singlestep_skip(p, regs);
}
} else if (cur) {
/* We probably hit a jprobe. Call its break handler. */
@ -434,6 +441,7 @@ static __used __kprobes void *trampoline_handler(struct pt_regs *regs)
struct hlist_node *tmp;
unsigned long flags, orig_ret_address = 0;
unsigned long trampoline_address = (unsigned long)&kretprobe_trampoline;
kprobe_opcode_t *correct_ret_addr = NULL;
INIT_HLIST_HEAD(&empty_rp);
kretprobe_hash_lock(current, &head, &flags);
@ -456,15 +464,7 @@ static __used __kprobes void *trampoline_handler(struct pt_regs *regs)
/* another task is sharing our hash bucket */
continue;
if (ri->rp && ri->rp->handler) {
__this_cpu_write(current_kprobe, &ri->rp->kp);
get_kprobe_ctlblk()->kprobe_status = KPROBE_HIT_ACTIVE;
ri->rp->handler(ri, regs);
__this_cpu_write(current_kprobe, NULL);
}
orig_ret_address = (unsigned long)ri->ret_addr;
recycle_rp_inst(ri, &empty_rp);
if (orig_ret_address != trampoline_address)
/*
@ -476,6 +476,33 @@ static __used __kprobes void *trampoline_handler(struct pt_regs *regs)
}
kretprobe_assert(ri, orig_ret_address, trampoline_address);
correct_ret_addr = ri->ret_addr;
hlist_for_each_entry_safe(ri, tmp, head, hlist) {
if (ri->task != current)
/* another task is sharing our hash bucket */
continue;
orig_ret_address = (unsigned long)ri->ret_addr;
if (ri->rp && ri->rp->handler) {
__this_cpu_write(current_kprobe, &ri->rp->kp);
get_kprobe_ctlblk()->kprobe_status = KPROBE_HIT_ACTIVE;
ri->ret_addr = correct_ret_addr;
ri->rp->handler(ri, regs);
__this_cpu_write(current_kprobe, NULL);
}
recycle_rp_inst(ri, &empty_rp);
if (orig_ret_address != trampoline_address)
/*
* This is the real return address. Any other
* instances associated with this task are for
* other calls deeper on the call stack
*/
break;
}
kretprobe_hash_unlock(current, &flags);
hlist_for_each_entry_safe(ri, tmp, &empty_rp, hlist) {

View File

@ -977,7 +977,10 @@ static void coverage_end(void)
void __naked __kprobes_test_case_start(void)
{
__asm__ __volatile__ (
"stmdb sp!, {r4-r11} \n\t"
"mov r2, sp \n\t"
"bic r3, r2, #7 \n\t"
"mov sp, r3 \n\t"
"stmdb sp!, {r2-r11} \n\t"
"sub sp, sp, #"__stringify(TEST_MEMORY_SIZE)"\n\t"
"bic r0, lr, #1 @ r0 = inline data \n\t"
"mov r1, sp \n\t"
@ -997,7 +1000,8 @@ void __naked __kprobes_test_case_end_32(void)
"movne pc, r0 \n\t"
"mov r0, r4 \n\t"
"add sp, sp, #"__stringify(TEST_MEMORY_SIZE)"\n\t"
"ldmia sp!, {r4-r11} \n\t"
"ldmia sp!, {r2-r11} \n\t"
"mov sp, r2 \n\t"
"mov pc, r0 \n\t"
);
}
@ -1013,7 +1017,8 @@ void __naked __kprobes_test_case_end_16(void)
"bxne r0 \n\t"
"mov r0, r4 \n\t"
"add sp, sp, #"__stringify(TEST_MEMORY_SIZE)"\n\t"
"ldmia sp!, {r4-r11} \n\t"
"ldmia sp!, {r2-r11} \n\t"
"mov sp, r2 \n\t"
"bx r0 \n\t"
);
}