From cd81a9170e69e018bbaba547c1fd85a585f5697a Mon Sep 17 00:00:00 2001 From: Mateusz Guzik Date: Tue, 23 Aug 2016 16:20:38 +0200 Subject: mm: introduce get_task_exe_file For more convenient access if one has a pointer to the task. As a minor nit take advantage of the fact that only task lock + rcu are needed to safely grab ->exe_file. This saves mm refcount dance. Use the helper in proc_exe_link. Signed-off-by: Mateusz Guzik Acked-by: Konstantin Khlebnikov Acked-by: Richard Guy Briggs Cc: # 4.3.x Signed-off-by: Paul Moore --- fs/proc/base.c | 7 +------ 1 file changed, 1 insertion(+), 6 deletions(-) (limited to 'fs/proc') diff --git a/fs/proc/base.c b/fs/proc/base.c index 0d163a8..da8b194 100644 --- a/fs/proc/base.c +++ b/fs/proc/base.c @@ -1552,18 +1552,13 @@ static const struct file_operations proc_pid_set_comm_operations = { static int proc_exe_link(struct dentry *dentry, struct path *exe_path) { struct task_struct *task; - struct mm_struct *mm; struct file *exe_file; task = get_proc_task(d_inode(dentry)); if (!task) return -ENOENT; - mm = get_task_mm(task); + exe_file = get_task_exe_file(task); put_task_struct(task); - if (!mm) - return -ENOENT; - exe_file = get_mm_exe_file(mm); - mmput(mm); if (exe_file) { *exe_path = exe_file->f_path; path_get(&exe_file->f_path); -- cgit v1.1 From ca120cf688874f4423e579e7cc5ddf7244aeca45 Mon Sep 17 00:00:00 2001 From: Dan Williams Date: Sat, 3 Sep 2016 10:38:03 -0700 Subject: mm: fix show_smap() for zone_device-pmd ranges Attempting to dump /proc//smaps for a process with pmd dax mappings currently results in the following VM_BUG_ONs: kernel BUG at mm/huge_memory.c:1105! task: ffff88045f16b140 task.stack: ffff88045be14000 RIP: 0010:[] [] follow_trans_huge_pmd+0x2cb/0x340 [..] Call Trace: [] smaps_pte_range+0xa0/0x4b0 [] ? vsnprintf+0x255/0x4c0 [] __walk_page_range+0x1fe/0x4d0 [] walk_page_vma+0x62/0x80 [] show_smap+0xa6/0x2b0 kernel BUG at fs/proc/task_mmu.c:585! RIP: 0010:[] [] smaps_pte_range+0x499/0x4b0 Call Trace: [] ? vsnprintf+0x255/0x4c0 [] __walk_page_range+0x1fe/0x4d0 [] walk_page_vma+0x62/0x80 [] show_smap+0xa6/0x2b0 These locations are sanity checking page flags that must be set for an anonymous transparent huge page, but are not set for the zone_device pages associated with dax mappings. Cc: Ross Zwisler Cc: Kirill A. Shutemov Acked-by: Andrew Morton Signed-off-by: Dan Williams --- fs/proc/task_mmu.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'fs/proc') diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c index 187d84e..f6fa99e 100644 --- a/fs/proc/task_mmu.c +++ b/fs/proc/task_mmu.c @@ -581,6 +581,8 @@ static void smaps_pmd_entry(pmd_t *pmd, unsigned long addr, mss->anonymous_thp += HPAGE_PMD_SIZE; else if (PageSwapBacked(page)) mss->shmem_thp += HPAGE_PMD_SIZE; + else if (is_zone_device_page(page)) + /* pass */; else VM_BUG_ON_PAGE(1, page); smaps_account(mss, page, true, pmd_young(*pmd), pmd_dirty(*pmd)); -- cgit v1.1