pagetable fixes: zero cr3 page and lower 1MB kernel va range

commit bb24de2 did memset for page frame allocations but cr3 page memset zero was missed. This commit fixes that. Lower 1MB range for kernel VA was coming out to be 80000000-80000000 but it needs to 0xffffffff80000000-ffffffff80100000. Signed-off-by: Deepak Gupta <[email protected]>
KernelTestFramework · Nov 24, 2020 · d28ca10 · d28ca10
1 parent 6da3351
commit d28ca10
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Showing 2 changed files with 23 additions and 18 deletions.
diff --git a/arch/x86/pagetables.c b/arch/x86/pagetables.c
@@ -115,8 +115,13 @@ static void *init_map_mfn(mfn_t mfn) {
 }
 
 static mfn_t get_cr3_mfn(cr3_t *cr3_entry) {
-    if (mfn_invalid(cr3_entry->mfn))
+    void *cr3_mapped = NULL;
+
+    if (mfn_invalid(cr3_entry->mfn)) {
         cr3_entry->mfn = get_free_frame();
+        cr3_mapped = init_map_mfn(cr3_entry->mfn);
+        memset(cr3_mapped, 0, PAGE_SIZE);
+    }
 
     return cr3_entry->mfn;
 }

diff --git a/mm/pmm.c b/mm/pmm.c
@@ -63,23 +63,23 @@ static size_t frames_count[MAX_PAGE_ORDER + 1];
 
 addr_range_t addr_ranges[] = {
     /* clang-format off */
-    IDENT_RANGE( "Low memory",  L1_PROT_RO,      0x0,               MB(1)           ),
-    IDENT_RANGE( ".text.init",  L1_PROT_RO,      __start_text_init, __end_text_init ),
-    IDENT_RANGE( ".data.init",  L1_PROT,         __start_data_init, __end_data_init ),
-    IDENT_RANGE( ".bss.init",   L1_PROT,         __start_bss_init,  __end_bss_init  ),
-
-    IDENT_RANGE( ".rmode",      L1_PROT,         __start_rmode,     __end_rmode     ),
-
-    USER_RANGE( ".text.user",   L1_PROT_USER_RO, __start_text_user, __end_text_user ),
-    USER_RANGE( ".data.user",   L1_PROT_USER,    __start_data_user, __end_data_user ),
-    USER_RANGE( ".bss.user",    L1_PROT_USER,    __start_bss_user,  __end_bss_user  ),
-
-    KERNEL_RANGE( "Low memory", L1_PROT,         0x0,               MB(1)           ),
-    KERNEL_RANGE( ".text",      L1_PROT_RO,      __start_text,      __end_text      ),
-    KERNEL_RANGE( ".data",      L1_PROT,         __start_data,      __end_data      ),
-    KERNEL_RANGE( ".bss",       L1_PROT,         __start_bss,       __end_bss       ),
-    KERNEL_RANGE( ".rodata",    L1_PROT_RO,      __start_rodata,    __end_rodata    ),
-    KERNEL_RANGE( ".symbols",   L1_PROT_RO,      __start_symbols,   __end_symbols   ),
+    IDENT_RANGE( "Low memory",  L1_PROT_RO,      0x0,                   MB(1)           ),
+    IDENT_RANGE( ".text.init",  L1_PROT_RO,      __start_text_init,     __end_text_init ),
+    IDENT_RANGE( ".data.init",  L1_PROT,         __start_data_init,     __end_data_init ),
+    IDENT_RANGE( ".bss.init",   L1_PROT,         __start_bss_init,      __end_bss_init  ),
+
+    IDENT_RANGE( ".rmode",      L1_PROT,         __start_rmode,         __end_rmode     ),
+
+    USER_RANGE( ".text.user",   L1_PROT_USER_RO, __start_text_user,     __end_text_user ),
+    USER_RANGE( ".data.user",   L1_PROT_USER,    __start_data_user,     __end_data_user ),
+    USER_RANGE( ".bss.user",    L1_PROT_USER,    __start_bss_user,      __end_bss_user  ),
+
+    KERNEL_RANGE( "Low memory", L1_PROT,         0x0 + VIRT_KERNEL_BASE, MB(1) + VIRT_KERNEL_BASE),
+    KERNEL_RANGE( ".text",      L1_PROT_RO,      __start_text,           __end_text      ),
+    KERNEL_RANGE( ".data",      L1_PROT,         __start_data,           __end_data      ),
+    KERNEL_RANGE( ".bss",       L1_PROT,         __start_bss,            __end_bss       ),
+    KERNEL_RANGE( ".rodata",    L1_PROT_RO,      __start_rodata,         __end_rodata    ),
+    KERNEL_RANGE( ".symbols",   L1_PROT_RO,      __start_symbols,        __end_symbols   ),
     /* clang-format on */
 
     {0x0} /* NULL array terminator */