ANDROID: 16K: Fix show maps CFI failure
If the kernel is built CONFIG_CFI_CLANG=y, reading smaps
may cause a panic. This is due to a failed CFI check; which
is triggered becuase the signature of the function pointer for
printing smaps padding VMAs does not match exactly with that
for show_smap().
Fix this by casting the function pointer to the expected type
based on whether printing maps or smaps padding.
Bug: 330117029
Bug: 327600007
Bug: 330767927
Bug: 328266487
Bug: 329803029
Change-Id: I65564a547dacbc4131f8557344c8c96e51f90cd5
Signed-off-by: Kalesh Singh <kaleshsingh@google.com>
diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
index 0b7f736..e429aad 100644
--- a/fs/proc/task_mmu.c
+++ b/fs/proc/task_mmu.c
@@ -351,7 +351,7 @@
if (vma_pages(vma))
show_map_vma(m, vma);
- show_map_pad_vma(vma, pad_vma, m, show_map_vma);
+ show_map_pad_vma(vma, pad_vma, m, show_map_vma, false);
return 0;
}
@@ -874,7 +874,7 @@
show_smap_vma_flags(m, vma);
show_pad:
- show_map_pad_vma(vma, pad_vma, m, (show_pad_vma_fn)show_smap);
+ show_map_pad_vma(vma, pad_vma, m, show_smap, true);
return 0;
}
diff --git a/include/linux/pgsize_migration.h b/include/linux/pgsize_migration.h
index 5c47ec2..fbfb1b9 100644
--- a/include/linux/pgsize_migration.h
+++ b/include/linux/pgsize_migration.h
@@ -43,8 +43,6 @@
#define VM_PAD_MASK (VM_TOTAL_PAD_PAGES << VM_PAD_SHIFT)
#define VMA_PAD_START(vma) (vma->vm_end - (vma_pad_pages(vma) << PAGE_SHIFT))
-typedef void (*show_pad_vma_fn)(struct seq_file *m, struct vm_area_struct *vma);
-
#if PAGE_SIZE == SZ_4K && defined(CONFIG_64BIT)
extern void vma_set_pad_pages(struct vm_area_struct *vma,
unsigned long nr_pages);
@@ -60,7 +58,7 @@
extern void show_map_pad_vma(struct vm_area_struct *vma,
struct vm_area_struct *pad,
- struct seq_file *m, show_pad_vma_fn func);
+ struct seq_file *m, void *func, bool smaps);
extern void split_pad_vma(struct vm_area_struct *vma, struct vm_area_struct *new,
unsigned long addr, int new_below);
@@ -92,7 +90,7 @@
static inline void show_map_pad_vma(struct vm_area_struct *vma,
struct vm_area_struct *pad,
- struct seq_file *m, show_pad_vma_fn func)
+ struct seq_file *m, void *func, bool smaps)
{
}
diff --git a/mm/pgsize_migration.c b/mm/pgsize_migration.c
index a156e0b..cfc9886e 100644
--- a/mm/pgsize_migration.c
+++ b/mm/pgsize_migration.c
@@ -20,6 +20,9 @@
#include <linux/slab.h>
#include <linux/sysfs.h>
+typedef void (*show_pad_maps_fn) (struct seq_file *m, struct vm_area_struct *vma);
+typedef int (*show_pad_smaps_fn) (struct seq_file *m, void *v);
+
#ifdef CONFIG_64BIT
#if PAGE_SIZE == SZ_4K
DEFINE_STATIC_KEY_TRUE(pgsize_migration_enabled);
@@ -303,7 +306,7 @@
* and @pad.
*/
void show_map_pad_vma(struct vm_area_struct *vma, struct vm_area_struct *pad,
- struct seq_file *m, show_pad_vma_fn func)
+ struct seq_file *m, void *func, bool smaps)
{
if (!pad)
return;
@@ -320,7 +323,10 @@
*/
BUG_ON(!vma);
- func(m, pad);
+ if (smaps)
+ ((show_pad_smaps_fn)func)(m, pad);
+ else
+ ((show_pad_maps_fn)func)(m, pad);
kfree(pad);
kfree(vma);
