From 6778948f9de86c3cfaf36725a7c87dcff9ba247f Mon Sep 17 00:00:00 2001
From: hc <hc@nodka.com>
Date: Mon, 11 Dec 2023 08:20:59 +0000
Subject: [PATCH] kernel_5.10 no rt
---
kernel/arch/parisc/mm/fault.c | 122 ++++++++++++++++++++++++++++++++++------
1 files changed, 104 insertions(+), 18 deletions(-)
diff --git a/kernel/arch/parisc/mm/fault.c b/kernel/arch/parisc/mm/fault.c
index c8e8b7c..5faa3cf 100644
--- a/kernel/arch/parisc/mm/fault.c
+++ b/kernel/arch/parisc/mm/fault.c
@@ -18,6 +18,7 @@
#include <linux/extable.h>
#include <linux/uaccess.h>
#include <linux/hugetlb.h>
+#include <linux/perf_event.h>
#include <asm/traps.h>
@@ -66,6 +67,7 @@
case 0x30000000: /* coproc2 */
if (bit22set(inst))
return VM_WRITE;
+ fallthrough;
case 0x0: /* indexed/memory management */
if (bit22set(inst)) {
@@ -273,15 +275,16 @@
if (!mm)
goto no_context;
- flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE;
+ flags = FAULT_FLAG_DEFAULT;
if (user_mode(regs))
flags |= FAULT_FLAG_USER;
acc_type = parisc_acctyp(code, regs->iir);
if (acc_type & VM_WRITE)
flags |= FAULT_FLAG_WRITE;
+ perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, address);
retry:
- down_read(&mm->mmap_sem);
+ mmap_read_lock(mm);
vma = find_vma_prev(mm, address, &prev_vma);
if (!vma || address < vma->vm_start)
goto check_expansion;
@@ -301,9 +304,9 @@
* fault.
*/
- fault = handle_mm_fault(vma, address, flags);
+ fault = handle_mm_fault(vma, address, flags, regs);
- if ((fault & VM_FAULT_RETRY) && fatal_signal_pending(current))
+ if (fault_signal_pending(fault, regs))
return;
if (unlikely(fault & VM_FAULT_ERROR)) {
@@ -322,23 +325,17 @@
BUG();
}
if (flags & FAULT_FLAG_ALLOW_RETRY) {
- if (fault & VM_FAULT_MAJOR)
- current->maj_flt++;
- else
- current->min_flt++;
if (fault & VM_FAULT_RETRY) {
- flags &= ~FAULT_FLAG_ALLOW_RETRY;
-
/*
- * No need to up_read(&mm->mmap_sem) as we would
+ * No need to mmap_read_unlock(mm) as we would
* have already released it in __lock_page_or_retry
* in mm/filemap.c.
*/
-
+ flags |= FAULT_FLAG_TRIED;
goto retry;
}
}
- up_read(&mm->mmap_sem);
+ mmap_read_unlock(mm);
return;
check_expansion:
@@ -350,7 +347,7 @@
* Something tried to access memory that isn't in our memory map..
*/
bad_area:
- up_read(&mm->mmap_sem);
+ mmap_read_unlock(mm);
if (user_mode(regs)) {
int signo, si_code;
@@ -373,7 +370,7 @@
}
/* probably address is outside of mapped file */
- /* fall through */
+ fallthrough;
case 17: /* NA data TLB miss / page fault */
case 18: /* Unaligned access - PCXS only */
signo = SIGBUS;
@@ -403,13 +400,13 @@
lsb = PAGE_SHIFT;
force_sig_mceerr(BUS_MCEERR_AR, (void __user *) address,
- lsb, current);
+ lsb);
return;
}
#endif
show_signal_msg(regs, code, address, tsk, vma);
- force_sig_fault(signo, si_code, (void __user *) address, current);
+ force_sig_fault(signo, si_code, (void __user *) address);
return;
}
@@ -422,8 +419,97 @@
parisc_terminate("Bad Address (null pointer deref?)", regs, code, address);
out_of_memory:
- up_read(&mm->mmap_sem);
+ mmap_read_unlock(mm);
if (!user_mode(regs))
goto no_context;
pagefault_out_of_memory();
}
+
+/* Handle non-access data TLB miss faults.
+ *
+ * For probe instructions, accesses to userspace are considered allowed
+ * if they lie in a valid VMA and the access type matches. We are not
+ * allowed to handle MM faults here so there may be situations where an
+ * actual access would fail even though a probe was successful.
+ */
+int
+handle_nadtlb_fault(struct pt_regs *regs)
+{
+ unsigned long insn = regs->iir;
+ int breg, treg, xreg, val = 0;
+ struct vm_area_struct *vma, *prev_vma;
+ struct task_struct *tsk;
+ struct mm_struct *mm;
+ unsigned long address;
+ unsigned long acc_type;
+
+ switch (insn & 0x380) {
+ case 0x280:
+ /* FDC instruction */
+ fallthrough;
+ case 0x380:
+ /* PDC and FIC instructions */
+ if (printk_ratelimit()) {
+ pr_warn("BUG: nullifying cache flush/purge instruction\n");
+ show_regs(regs);
+ }
+ if (insn & 0x20) {
+ /* Base modification */
+ breg = (insn >> 21) & 0x1f;
+ xreg = (insn >> 16) & 0x1f;
+ if (breg && xreg)
+ regs->gr[breg] += regs->gr[xreg];
+ }
+ regs->gr[0] |= PSW_N;
+ return 1;
+
+ case 0x180:
+ /* PROBE instruction */
+ treg = insn & 0x1f;
+ if (regs->isr) {
+ tsk = current;
+ mm = tsk->mm;
+ if (mm) {
+ /* Search for VMA */
+ address = regs->ior;
+ mmap_read_lock(mm);
+ vma = find_vma_prev(mm, address, &prev_vma);
+ mmap_read_unlock(mm);
+
+ /*
+ * Check if access to the VMA is okay.
+ * We don't allow for stack expansion.
+ */
+ acc_type = (insn & 0x40) ? VM_WRITE : VM_READ;
+ if (vma
+ && address >= vma->vm_start
+ && (vma->vm_flags & acc_type) == acc_type)
+ val = 1;
+ }
+ }
+ if (treg)
+ regs->gr[treg] = val;
+ regs->gr[0] |= PSW_N;
+ return 1;
+
+ case 0x300:
+ /* LPA instruction */
+ if (insn & 0x20) {
+ /* Base modification */
+ breg = (insn >> 21) & 0x1f;
+ xreg = (insn >> 16) & 0x1f;
+ if (breg && xreg)
+ regs->gr[breg] += regs->gr[xreg];
+ }
+ treg = insn & 0x1f;
+ if (treg)
+ regs->gr[treg] = 0;
+ regs->gr[0] |= PSW_N;
+ return 1;
+
+ default:
+ break;
+ }
+
+ return 0;
+}
--
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