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Diffstat (limited to 'arch/arm64/mm/fault.c')
-rw-r--r--arch/arm64/mm/fault.c77
1 files changed, 58 insertions, 19 deletions
diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c
index 1f22a41565a3..89993c4be1be 100644
--- a/arch/arm64/mm/fault.c
+++ b/arch/arm64/mm/fault.c
@@ -34,6 +34,7 @@
#include <linux/hugetlb.h>
#include <asm/bug.h>
+#include <asm/cmpxchg.h>
#include <asm/cpufeature.h>
#include <asm/exception.h>
#include <asm/debug-monitors.h>
@@ -82,6 +83,49 @@ static inline int notify_page_fault(struct pt_regs *regs, unsigned int esr)
}
#endif
+static void data_abort_decode(unsigned int esr)
+{
+ pr_alert("Data abort info:\n");
+
+ if (esr & ESR_ELx_ISV) {
+ pr_alert(" Access size = %u byte(s)\n",
+ 1U << ((esr & ESR_ELx_SAS) >> ESR_ELx_SAS_SHIFT));
+ pr_alert(" SSE = %lu, SRT = %lu\n",
+ (esr & ESR_ELx_SSE) >> ESR_ELx_SSE_SHIFT,
+ (esr & ESR_ELx_SRT_MASK) >> ESR_ELx_SRT_SHIFT);
+ pr_alert(" SF = %lu, AR = %lu\n",
+ (esr & ESR_ELx_SF) >> ESR_ELx_SF_SHIFT,
+ (esr & ESR_ELx_AR) >> ESR_ELx_AR_SHIFT);
+ } else {
+ pr_alert(" ISV = 0, ISS = 0x%08lu\n", esr & ESR_ELx_ISS_MASK);
+ }
+
+ pr_alert(" CM = %lu, WnR = %lu\n",
+ (esr & ESR_ELx_CM) >> ESR_ELx_CM_SHIFT,
+ (esr & ESR_ELx_WNR) >> ESR_ELx_WNR_SHIFT);
+}
+
+/*
+ * Decode mem abort information
+ */
+static void mem_abort_decode(unsigned int esr)
+{
+ pr_alert("Mem abort info:\n");
+
+ pr_alert(" Exception class = %s, IL = %u bits\n",
+ esr_get_class_string(esr),
+ (esr & ESR_ELx_IL) ? 32 : 16);
+ pr_alert(" SET = %lu, FnV = %lu\n",
+ (esr & ESR_ELx_SET_MASK) >> ESR_ELx_SET_SHIFT,
+ (esr & ESR_ELx_FnV) >> ESR_ELx_FnV_SHIFT);
+ pr_alert(" EA = %lu, S1PTW = %lu\n",
+ (esr & ESR_ELx_EA) >> ESR_ELx_EA_SHIFT,
+ (esr & ESR_ELx_S1PTW) >> ESR_ELx_S1PTW_SHIFT);
+
+ if (esr_is_data_abort(esr))
+ data_abort_decode(esr);
+}
+
/*
* Dump out the page tables associated with 'addr' in the currently active mm.
*/
@@ -139,7 +183,6 @@ void show_pte(unsigned long addr)
pr_cont("\n");
}
-#ifdef CONFIG_ARM64_HW_AFDBM
/*
* This function sets the access flags (dirty, accessed), as well as write
* permission, and only to a more permissive setting.
@@ -154,18 +197,13 @@ int ptep_set_access_flags(struct vm_area_struct *vma,
unsigned long address, pte_t *ptep,
pte_t entry, int dirty)
{
- pteval_t old_pteval;
- unsigned int tmp;
+ pteval_t old_pteval, pteval;
if (pte_same(*ptep, entry))
return 0;
/* only preserve the access flags and write permission */
- pte_val(entry) &= PTE_AF | PTE_WRITE | PTE_DIRTY;
-
- /* set PTE_RDONLY if actual read-only or clean PTE */
- if (!pte_write(entry) || !pte_sw_dirty(entry))
- pte_val(entry) |= PTE_RDONLY;
+ pte_val(entry) &= PTE_RDONLY | PTE_AF | PTE_WRITE | PTE_DIRTY;
/*
* Setting the flags must be done atomically to avoid racing with the
@@ -174,21 +212,18 @@ int ptep_set_access_flags(struct vm_area_struct *vma,
* (calculated as: a & b == ~(~a | ~b)).
*/
pte_val(entry) ^= PTE_RDONLY;
- asm volatile("// ptep_set_access_flags\n"
- " prfm pstl1strm, %2\n"
- "1: ldxr %0, %2\n"
- " eor %0, %0, %3 // negate PTE_RDONLY in *ptep\n"
- " orr %0, %0, %4 // set flags\n"
- " eor %0, %0, %3 // negate final PTE_RDONLY\n"
- " stxr %w1, %0, %2\n"
- " cbnz %w1, 1b\n"
- : "=&r" (old_pteval), "=&r" (tmp), "+Q" (pte_val(*ptep))
- : "L" (PTE_RDONLY), "r" (pte_val(entry)));
+ pteval = READ_ONCE(pte_val(*ptep));
+ do {
+ old_pteval = pteval;
+ pteval ^= PTE_RDONLY;
+ pteval |= pte_val(entry);
+ pteval ^= PTE_RDONLY;
+ pteval = cmpxchg_relaxed(&pte_val(*ptep), old_pteval, pteval);
+ } while (pteval != old_pteval);
flush_tlb_fix_spurious_fault(vma, address);
return 1;
}
-#endif
static bool is_el1_instruction_abort(unsigned int esr)
{
@@ -248,6 +283,8 @@ static void __do_kernel_fault(unsigned long addr, unsigned int esr,
pr_alert("Unable to handle kernel %s at virtual address %08lx\n", msg,
addr);
+ mem_abort_decode(esr);
+
show_pte(addr);
die("Oops", regs, esr);
bust_spinlocks(0);
@@ -705,6 +742,8 @@ asmlinkage void __exception do_mem_abort(unsigned long addr, unsigned int esr,
pr_alert("Unhandled fault: %s (0x%08x) at 0x%016lx\n",
inf->name, esr, addr);
+ mem_abort_decode(esr);
+
info.si_signo = inf->sig;
info.si_errno = 0;
info.si_code = inf->code;