moto mmap fault driver:Optimize the code flow
Remove the kprobe & lookup symbol make sure the android oem data is the one previous saved Change-Id: I7f63dd8fe5033fc9e1bcbf6182122da9fe7e7e85 Signed-off-by: William Liu <a17671@motorola.com> Reviewed-on: https://gerrit.mot.com/2658819 SME-Granted: SME Approvals Granted SLTApproved: Slta Waiver Tested-by: Jira Key Reviewed-by: Xiangpo Zhao <zhaoxp3@motorola.com> Submit-Approved: Jira Key Reviewed-on: https://gerrit.mot.com/2676238 Reviewed-by: Huosheng Liao <liaohs@motorola.com>
This commit is contained in:
William Liu authored and Xiaojun Ji committed
1 parent
d06ffd55fe
commit
26c4796240
1 file changed
+58
-89
@@ -12,123 +12,92 @@
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*/
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#include <linux/module.h>
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#include <linux/kernel.h>
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#include <linux/slab.h>
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#include <linux/mm.h> // struct mm_struct, apply_to_page_range()
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#include <linux/kallsyms.h> // kallsyms_lookup_name()
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#include <linux/vmalloc.h> // vm_unmap_aliases()
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#include <trace/hooks/mm.h>
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#include <linux/kprobes.h>
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#include <linux/version.h>
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#include <linux/pagemap.h>
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typedef struct page *(*page_cache_get_page_funct_t)(struct address_space *mapping, pgoff_t offset, int fgp_flags, gfp_t gfp_mask);
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static page_cache_get_page_funct_t page_cache_get_page_func;
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typedef unsigned long (*kallsyms_lookup_name_func_t)(const char *name);
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static kallsyms_lookup_name_func_t kallsyms_lookup_name_func;
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static int max_ra_pages = 8;
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module_param(max_ra_pages, int, S_IRUGO | S_IWUSR);
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MODULE_PARM_DESC(max_ra_pages, "Max read ahead pages");
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static void __nocfi filemap_fault_get_page(void *p, struct vm_fault *vmf, struct page **page_out, bool *retry)
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{
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struct file *file = vmf->vma->vm_file;
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pgoff_t offset = vmf->pgoff;
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struct page *page = NULL;
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struct file_ra_state *ra = NULL;
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struct address_space *mapping = NULL;
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unsigned int mmap_miss;
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unsigned int old_ra_pages = 0;
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struct file *file = vmf->vma->vm_file;
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pgoff_t offset = vmf->pgoff;
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struct page *page = NULL;
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struct file_ra_state *ra = NULL;
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struct address_space *mapping = NULL;
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unsigned int mmap_miss;
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unsigned int old_ra_pages = 0;
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if (!file)
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return;
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if (!file)
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return;
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ra = &file->f_ra;
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if(!ra)
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return;
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ra = &file->f_ra;
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if(!ra)
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return;
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mapping = file->f_mapping;
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if (page_cache_get_page_func)
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page = page_cache_get_page_func(mapping, offset, 0, 0);
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mapping = file->f_mapping;
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page = find_get_page(mapping, offset);
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if (likely(page) && !(vmf->flags & FAULT_FLAG_TRIED)) {
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put_page(page);
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if (likely(page) && !(vmf->flags & FAULT_FLAG_TRIED)) {
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put_page(page);
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} else if (!page) {
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mmap_miss = READ_ONCE(ra->mmap_miss);
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if ((vmf->vma->vm_flags & VM_RAND_READ) ||
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(!ra->ra_pages) ||
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(vmf->vma->vm_flags & VM_SEQ_READ) ||
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mmap_miss > 100) {
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return;
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} else {
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old_ra_pages = ra->ra_pages;
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if (ra->ra_pages > max_ra_pages) {
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ra->ra_pages = max_ra_pages; // reduce the read ahead limit to 8 pages
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vmf->android_oem_data1[0] = old_ra_pages;
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vmf->android_oem_data1[1] = max_ra_pages;
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}
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return;
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}
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} else {
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put_page(page);
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}
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mmap_miss = READ_ONCE(ra->mmap_miss);
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if ((vmf->vma->vm_flags & VM_RAND_READ) ||
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(!ra->ra_pages) ||
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(vmf->vma->vm_flags & VM_SEQ_READ) ||
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mmap_miss > 100) {
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return;
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} else {
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old_ra_pages = ra->ra_pages;
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if (ra->ra_pages > max_ra_pages) {
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ra->ra_pages = max_ra_pages; // reduce the read ahead limit to 8 pages
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vmf->android_oem_data1[0] = old_ra_pages;
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vmf->android_oem_data1[1] = max_ra_pages;
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}
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return;
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}
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} else {
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put_page(page);
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}
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return;
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return;
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}
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static void __nocfi filemap_fault_cache_page(void *p, struct vm_fault *vmf, struct page *page)
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{
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struct file *file = vmf->vma->vm_file;
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struct file_ra_state *ra = NULL;
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struct file *file = vmf->vma->vm_file;
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struct file_ra_state *ra = NULL;
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if (!file)
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return;
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if (!file)
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return;
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ra = &file->f_ra;
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if(!ra)
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return;
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ra = &file->f_ra;
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if(!ra)
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return;
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if ((ra->ra_pages == max_ra_pages) && (vmf->android_oem_data1[0] != 0) && (vmf->android_oem_data1[1] != 0)) {
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ra->ra_pages = (unsigned long)vmf->android_oem_data1[0]; //restore the old ra_pages
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vmf->android_oem_data1[0] = 0;
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vmf->android_oem_data1[1] = 0;
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}
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if ((ra->ra_pages == max_ra_pages) && (vmf->android_oem_data1[0] != 0)
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&& (vmf->android_oem_data1[1] == max_ra_pages)) {
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ra->ra_pages = (unsigned long)vmf->android_oem_data1[0]; //restore the old ra_pages
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vmf->android_oem_data1[0] = 0;
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vmf->android_oem_data1[1] = 0;
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}
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}
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static int __nocfi __init moto_mmap_fault_init(void)
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{
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int ret = 0;
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struct kprobe kp = {
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.symbol_name = "kallsyms_lookup_name",
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};
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int ret = 0;
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ret = register_trace_android_vh_filemap_fault_get_page(filemap_fault_get_page, NULL) ?:
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register_trace_android_vh_filemap_fault_cache_page(filemap_fault_cache_page, NULL);
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ret = register_kprobe(&kp);
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if (ret < 0) {
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pr_err("Failed to register kprobe, %d\n", ret);
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return ret;
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}
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unregister_kprobe(&kp);
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kallsyms_lookup_name_func = (kallsyms_lookup_name_func_t)kp.addr;
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if (!kallsyms_lookup_name_func) {
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pr_err("Failed to get kallsyms_lookup_name address\n");
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return -ENXIO;
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}
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page_cache_get_page_func = (void *)kallsyms_lookup_name_func("pagecache_get_page");
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if (!page_cache_get_page_func) {
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pr_err("Failed to get required function\n");
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return -ENXIO;
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}
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ret = register_trace_android_vh_filemap_fault_get_page(filemap_fault_get_page, NULL) ?:
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register_trace_android_vh_filemap_fault_cache_page(filemap_fault_cache_page, NULL);
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if (ret != 0)
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return -ENXIO;
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else
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return 0;
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if (ret != 0)
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return -ENXIO;
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else
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return 0;
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}
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static void __nocfi __exit moto_mmap_fault_exit(void)
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{
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unregister_trace_android_vh_filemap_fault_get_page(filemap_fault_get_page, NULL);
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unregister_trace_android_vh_filemap_fault_cache_page(filemap_fault_cache_page, NULL);
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unregister_trace_android_vh_filemap_fault_get_page(filemap_fault_get_page, NULL);
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unregister_trace_android_vh_filemap_fault_cache_page(filemap_fault_cache_page, NULL);
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}
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module_init(moto_mmap_fault_init);
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