From 37f49e37ab4cb5d0bc4c60eb5c6d4dd57db767bb Mon Sep 17 00:00:00 2001
From: hc <hc@nodka.com>
Date: Fri, 10 May 2024 07:44:59 +0000
Subject: [PATCH] gmac get mac form eeprom

---
 kernel/arch/m68k/kernel/sys_m68k.c |   26 ++++++++++++++++++--------
 1 files changed, 18 insertions(+), 8 deletions(-)

diff --git a/kernel/arch/m68k/kernel/sys_m68k.c b/kernel/arch/m68k/kernel/sys_m68k.c
index 6363ec8..f55bdcb 100644
--- a/kernel/arch/m68k/kernel/sys_m68k.c
+++ b/kernel/arch/m68k/kernel/sys_m68k.c
@@ -388,6 +388,8 @@
 		ret = -EPERM;
 		if (!capable(CAP_SYS_ADMIN))
 			goto out;
+
+		mmap_read_lock(current->mm);
 	} else {
 		struct vm_area_struct *vma;
 
@@ -399,7 +401,7 @@
 		 * Verify that the specified address region actually belongs
 		 * to this process.
 		 */
-		down_read(&current->mm->mmap_sem);
+		mmap_read_lock(current->mm);
 		vma = find_vma(current->mm, addr);
 		if (!vma || addr < vma->vm_start || addr + len > vma->vm_end)
 			goto out_unlock;
@@ -450,7 +452,7 @@
 	    }
 	}
 out_unlock:
-	up_read(&current->mm->mmap_sem);
+	mmap_read_unlock(current->mm);
 out:
 	return ret;
 }
@@ -465,16 +467,24 @@
 	for (;;) {
 		struct mm_struct *mm = current->mm;
 		pgd_t *pgd;
+		p4d_t *p4d;
+		pud_t *pud;
 		pmd_t *pmd;
 		pte_t *pte;
 		spinlock_t *ptl;
 		unsigned long mem_value;
 
-		down_read(&mm->mmap_sem);
+		mmap_read_lock(mm);
 		pgd = pgd_offset(mm, (unsigned long)mem);
 		if (!pgd_present(*pgd))
 			goto bad_access;
-		pmd = pmd_offset(pgd, (unsigned long)mem);
+		p4d = p4d_offset(pgd, (unsigned long)mem);
+		if (!p4d_present(*p4d))
+			goto bad_access;
+		pud = pud_offset(p4d, (unsigned long)mem);
+		if (!pud_present(*pud))
+			goto bad_access;
+		pmd = pmd_offset(pud, (unsigned long)mem);
 		if (!pmd_present(*pmd))
 			goto bad_access;
 		pte = pte_offset_map_lock(mm, pmd, (unsigned long)mem, &ptl);
@@ -493,11 +503,11 @@
 			__put_user(newval, mem);
 
 		pte_unmap_unlock(pte, ptl);
-		up_read(&mm->mmap_sem);
+		mmap_read_unlock(mm);
 		return mem_value;
 
 	      bad_access:
-		up_read(&mm->mmap_sem);
+		mmap_read_unlock(mm);
 		/* This is not necessarily a bad access, we can get here if
 		   a memory we're trying to write to should be copied-on-write.
 		   Make the kernel do the necessary page stuff, then re-iterate.
@@ -537,13 +547,13 @@
 	struct mm_struct *mm = current->mm;
 	unsigned long mem_value;
 
-	down_read(&mm->mmap_sem);
+	mmap_read_lock(mm);
 
 	mem_value = *mem;
 	if (mem_value == oldval)
 		*mem = newval;
 
-	up_read(&mm->mmap_sem);
+	mmap_read_unlock(mm);
 	return mem_value;
 }
 

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