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vmap: fix wrong mmu setting in check sp funciton [1/1]

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PD#TV-9668

Problem:
If sp address is in linear mapping range, check_sp_fault_again
function in vmap fault handler will still map a new page for it.
This will cause some data in R/W section polluted.

Solution:
Avoid map page if sp is in linear range.

Verify:
TL1 x301

Change-Id: I0e02a2048b586854c528cd3eeafb725751b9dc82
Signed-off-by: Tao Zeng <tao.zeng@amlogic.com>
This commit is contained in:
Tao Zeng
2019-09-17 15:00:12 +08:00
committed by Luke Go
parent 7b16736376
commit f3ff8e986f
2 changed files with 30 additions and 6 deletions
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30
drivers/amlogic/memory_ext/vmap_stack.c
View File

@@ -52,6 +52,8 @@
static unsigned long stack_shrink_jiffies;
static unsigned char vmap_shrink_enable;
static atomic_t vmap_stack_size;
static atomic_t vmap_fault_count;
static atomic_t vmap_pre_handle_count;
static struct aml_vmap *avmap;
#ifdef CONFIG_ARM64
@@ -454,6 +456,18 @@ static void check_sp_fault_again(struct pt_regs *regs)
#endif
addr = sp - sizeof(*regs);
/*
* When we handle vmap stack fault, we are in pre-allcated
* per-cpu vmap stack. But if sp is near bottom of a page and we
* return to normal handler, sp may down grow to another page
* to cause a vmap fault again. So we need map next page for
* stack before page-fault happen.
*
* But we need check sp is realy in vmap stack range.
*/
if (!is_vmap_addr(addr)) /* addr may in linear mapping */
return;
if (sp && ((addr & PAGE_MASK) != (sp & PAGE_MASK))) {
/*
* will fault when we copy back context, so handle
@@ -477,6 +491,7 @@ static void check_sp_fault_again(struct pt_regs *regs)
mod_delayed_work(system_highpri_wq, &avmap->mwork, 0);
D("map page:%5lx for addr:%lx\n", page_to_pfn(page), addr);
atomic_inc(&vmap_pre_handle_count);
#if DEBUG
show_fault_stack(addr, regs);
#endif
@@ -557,6 +572,7 @@ int handle_vmap_fault(unsigned long addr, unsigned int esr,
if (cache <= (VMAP_CACHE_PAGE / 2))
mod_delayed_work(system_highpri_wq, &avmap->mwork, 0);
atomic_inc(&vmap_fault_count);
D("map page:%5lx for addr:%lx\n", page_to_pfn(page), addr);
#if DEBUG
show_fault_stack(addr, regs);
@@ -586,6 +602,20 @@ static int shrink_vm_stack(unsigned long low, unsigned long high)
return pages;
}
void arch_report_meminfo(struct seq_file *m)
{
unsigned long kb = 1 << (PAGE_SHIFT - 10);
unsigned long tmp1, tmp2, tmp3;
tmp1 = kb * atomic_read(&vmap_stack_size);
tmp2 = kb * atomic_read(&vmap_fault_count);
tmp3 = kb * atomic_read(&vmap_pre_handle_count);
seq_printf(m, "VmapStack: %8ld kB\n", tmp1);
seq_printf(m, "VmapFault: %8ld kB\n", tmp2);
seq_printf(m, "VmapPfault: %8ld kB\n", tmp3);
}
static unsigned long get_task_stack_floor(unsigned long sp)
{
unsigned long end;

6
fs/proc/meminfo.c
View File

@@ -15,9 +15,6 @@
#ifdef CONFIG_CMA
#include <linux/cma.h>
#endif
#ifdef CONFIG_AMLOGIC_VMAP
#include <linux/amlogic/vmap_stack.h>
#endif
#include <asm/page.h>
#include <asm/pgtable.h>
#include "internal.h"
@@ -156,9 +153,6 @@ static int meminfo_proc_show(struct seq_file *m, void *v)
show_val_kb(m, "CmaFree: ",
global_page_state(NR_FREE_CMA_PAGES));
#endif
#ifdef CONFIG_AMLOGIC_VMAP
show_val_kb(m, "VmapStack: ", get_vmap_stack_size());
#endif
hugetlb_report_meminfo(m);