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Diffstat (limited to 'arch/arm64/mm/fault.c')
-rw-r--r--arch/arm64/mm/fault.c98
1 files changed, 43 insertions, 55 deletions
diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c
index afadae6682e..bcc965e2cce 100644
--- a/arch/arm64/mm/fault.c
+++ b/arch/arm64/mm/fault.c
@@ -32,6 +32,7 @@
#include <asm/exception.h>
#include <asm/debug-monitors.h>
+#include <asm/esr.h>
#include <asm/system_misc.h>
#include <asm/pgtable.h>
#include <asm/tlbflush.h>
@@ -57,16 +58,16 @@ void show_pte(struct mm_struct *mm, unsigned long addr)
pmd_t *pmd;
pte_t *pte;
- if (pgd_none_or_clear_bad(pgd))
+ if (pgd_none(*pgd) || pgd_bad(*pgd))
break;
pud = pud_offset(pgd, addr);
- if (pud_none_or_clear_bad(pud))
+ if (pud_none(*pud) || pud_bad(*pud))
break;
pmd = pmd_offset(pud, addr);
printk(", *pmd=%016llx", pmd_val(*pmd));
- if (pmd_none_or_clear_bad(pmd))
+ if (pmd_none(*pmd) || pmd_bad(*pmd))
break;
pte = pte_offset_map(pmd, addr);
@@ -113,7 +114,8 @@ static void __do_user_fault(struct task_struct *tsk, unsigned long addr,
{
struct siginfo si;
- if (show_unhandled_signals) {
+ if (show_unhandled_signals && unhandled_signal(tsk, sig) &&
+ printk_ratelimit()) {
pr_info("%s[%d]: unhandled %s (%d) at 0x%08lx, esr 0x%03x\n",
tsk->comm, task_pid_nr(tsk), fault_name(esr), sig,
addr, esr);
@@ -122,6 +124,7 @@ static void __do_user_fault(struct task_struct *tsk, unsigned long addr,
}
tsk->thread.fault_address = addr;
+ tsk->thread.fault_code = esr;
si.si_signo = sig;
si.si_errno = 0;
si.si_code = code;
@@ -129,7 +132,7 @@ static void __do_user_fault(struct task_struct *tsk, unsigned long addr,
force_sig_info(sig, &si, tsk);
}
-void do_bad_area(unsigned long addr, unsigned int esr, struct pt_regs *regs)
+static void do_bad_area(unsigned long addr, unsigned int esr, struct pt_regs *regs)
{
struct task_struct *tsk = current;
struct mm_struct *mm = tsk->active_mm;
@@ -147,28 +150,10 @@ void do_bad_area(unsigned long addr, unsigned int esr, struct pt_regs *regs)
#define VM_FAULT_BADMAP 0x010000
#define VM_FAULT_BADACCESS 0x020000
-#define ESR_WRITE (1 << 6)
#define ESR_LNX_EXEC (1 << 24)
-/*
- * Check that the permissions on the VMA allow for the fault which occurred.
- * If we encountered a write fault, we must have write permission, otherwise
- * we allow any permission.
- */
-static inline bool access_error(unsigned int esr, struct vm_area_struct *vma)
-{
- unsigned int mask = VM_READ | VM_WRITE | VM_EXEC;
-
- if (esr & ESR_WRITE)
- mask = VM_WRITE;
- if (esr & ESR_LNX_EXEC)
- mask = VM_EXEC;
-
- return vma->vm_flags & mask ? false : true;
-}
-
static int __do_page_fault(struct mm_struct *mm, unsigned long addr,
- unsigned int esr, unsigned int flags,
+ unsigned int mm_flags, unsigned long vm_flags,
struct task_struct *tsk)
{
struct vm_area_struct *vma;
@@ -186,12 +171,17 @@ static int __do_page_fault(struct mm_struct *mm, unsigned long addr,
* it.
*/
good_area:
- if (access_error(esr, vma)) {
+ /*
+ * Check that the permissions on the VMA allow for the fault which
+ * occurred. If we encountered a write or exec fault, we must have
+ * appropriate permissions, otherwise we allow any permission.
+ */
+ if (!(vma->vm_flags & vm_flags)) {
fault = VM_FAULT_BADACCESS;
goto out;
}
- return handle_mm_fault(mm, vma, addr & PAGE_MASK, flags);
+ return handle_mm_fault(mm, vma, addr & PAGE_MASK, mm_flags);
check_stack:
if (vma->vm_flags & VM_GROWSDOWN && !expand_stack(vma, addr))
@@ -206,9 +196,8 @@ static int __kprobes do_page_fault(unsigned long addr, unsigned int esr,
struct task_struct *tsk;
struct mm_struct *mm;
int fault, sig, code;
- int write = esr & ESR_WRITE;
- unsigned int flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE |
- (write ? FAULT_FLAG_WRITE : 0);
+ unsigned long vm_flags = VM_READ | VM_WRITE | VM_EXEC;
+ unsigned int mm_flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE;
tsk = current;
mm = tsk->mm;
@@ -224,6 +213,16 @@ static int __kprobes do_page_fault(unsigned long addr, unsigned int esr,
if (in_atomic() || !mm)
goto no_context;
+ if (user_mode(regs))
+ mm_flags |= FAULT_FLAG_USER;
+
+ if (esr & ESR_LNX_EXEC) {
+ vm_flags = VM_EXEC;
+ } else if ((esr & ESR_EL1_WRITE) && !(esr & ESR_EL1_CM)) {
+ vm_flags = VM_WRITE;
+ mm_flags |= FAULT_FLAG_WRITE;
+ }
+
/*
* As per x86, we may deadlock here. However, since the kernel only
* validly references user space from well defined areas of the code,
@@ -246,7 +245,7 @@ retry:
#endif
}
- fault = __do_page_fault(mm, addr, esr, flags, tsk);
+ fault = __do_page_fault(mm, addr, mm_flags, vm_flags, tsk);
/*
* If we need to retry but a fatal signal is pending, handle the
@@ -263,7 +262,7 @@ retry:
*/
perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, addr);
- if (flags & FAULT_FLAG_ALLOW_RETRY) {
+ if (mm_flags & FAULT_FLAG_ALLOW_RETRY) {
if (fault & VM_FAULT_MAJOR) {
tsk->maj_flt++;
perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MAJ, 1, regs,
@@ -278,7 +277,7 @@ retry:
* Clear FAULT_FLAG_ALLOW_RETRY to avoid any risk of
* starvation.
*/
- flags &= ~FAULT_FLAG_ALLOW_RETRY;
+ mm_flags &= ~FAULT_FLAG_ALLOW_RETRY;
goto retry;
}
}
@@ -292,6 +291,13 @@ retry:
VM_FAULT_BADACCESS))))
return 0;
+ /*
+ * If we are in kernel mode at this point, we have no context to
+ * handle this fault with.
+ */
+ if (!user_mode(regs))
+ goto no_context;
+
if (fault & VM_FAULT_OOM) {
/*
* We ran out of memory, call the OOM killer, and return to
@@ -302,13 +308,6 @@ retry:
return 0;
}
- /*
- * If we are in kernel mode at this point, we have no context to
- * handle this fault with.
- */
- if (!user_mode(regs))
- goto no_context;
-
if (fault & VM_FAULT_SIGBUS) {
/*
* We had some memory, but were unable to successfully fix up
@@ -363,17 +362,6 @@ static int __kprobes do_translation_fault(unsigned long addr,
}
/*
- * Some section permission faults need to be handled gracefully. They can
- * happen due to a __{get,put}_user during an oops.
- */
-static int do_sect_fault(unsigned long addr, unsigned int esr,
- struct pt_regs *regs)
-{
- do_bad_area(addr, esr, regs);
- return 0;
-}
-
-/*
* This abort handler always returns "fault".
*/
static int do_bad(unsigned long addr, unsigned int esr, struct pt_regs *regs)
@@ -396,12 +384,12 @@ static struct fault_info {
{ do_translation_fault, SIGSEGV, SEGV_MAPERR, "level 2 translation fault" },
{ do_page_fault, SIGSEGV, SEGV_MAPERR, "level 3 translation fault" },
{ do_bad, SIGBUS, 0, "reserved access flag fault" },
- { do_bad, SIGSEGV, SEGV_ACCERR, "level 1 access flag fault" },
- { do_bad, SIGSEGV, SEGV_ACCERR, "level 2 access flag fault" },
+ { do_page_fault, SIGSEGV, SEGV_ACCERR, "level 1 access flag fault" },
+ { do_page_fault, SIGSEGV, SEGV_ACCERR, "level 2 access flag fault" },
{ do_page_fault, SIGSEGV, SEGV_ACCERR, "level 3 access flag fault" },
{ do_bad, SIGBUS, 0, "reserved permission fault" },
- { do_bad, SIGSEGV, SEGV_ACCERR, "level 1 permission fault" },
- { do_sect_fault, SIGSEGV, SEGV_ACCERR, "level 2 permission fault" },
+ { do_page_fault, SIGSEGV, SEGV_ACCERR, "level 1 permission fault" },
+ { do_page_fault, SIGSEGV, SEGV_ACCERR, "level 2 permission fault" },
{ do_page_fault, SIGSEGV, SEGV_ACCERR, "level 3 permission fault" },
{ do_bad, SIGBUS, 0, "synchronous external abort" },
{ do_bad, SIGBUS, 0, "asynchronous external abort" },
@@ -537,7 +525,7 @@ asmlinkage int __exception do_debug_exception(unsigned long addr,
info.si_errno = 0;
info.si_code = inf->code;
info.si_addr = (void __user *)addr;
- arm64_notify_die("", regs, &info, esr);
+ arm64_notify_die("", regs, &info, 0);
return 0;
}
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2025-11-09 12:18:05 +0000