proc: replace __get_free_page() with kmalloc()

A few functions in fs/proc/base.c use __get_free_page() to allocate a
temporary buffer.

kmalloc() is a better API for such use and it also provides better
scalability and more debugging possibilities.

Replace use of __get_free_page() with kmalloc().

Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Link: https://patch.msgid.link/20260523-b4-fs-v1-2-275e36a83f0e@kernel.org
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>

diff --git a/fs/proc/base.c b/fs/proc/base.c
index d9acfa89c894bd1608580331e1d5b3018c59123b..e129dc509b79483f43ce9d4ac9573bc3dad36ab9 100644 (file)
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -261,7 +261,7 @@ static ssize_t get_mm_proctitle(struct mm_struct *mm, char __user *buf,
        if (pos >= PAGE_SIZE)
                return 0;
 
-       page = (char *)__get_free_page(GFP_KERNEL);
+       page = kmalloc(PAGE_SIZE, GFP_KERNEL);
        if (!page)
                return -ENOMEM;
 
@@ -284,7 +284,7 @@ static ssize_t get_mm_proctitle(struct mm_struct *mm, char __user *buf,
                        ret = len;
                }
        }
-       free_page((unsigned long)page);
+       kfree(page);
        return ret;
 }
 
@@ -347,7 +347,7 @@ static ssize_t get_mm_cmdline(struct mm_struct *mm, char __user *buf,
        if (count > arg_end - pos)
                count = arg_end - pos;
 
-       page = (char *)__get_free_page(GFP_KERNEL);
+       page = kmalloc(PAGE_SIZE, GFP_KERNEL);
        if (!page)
                return -ENOMEM;
 
@@ -371,7 +371,7 @@ static ssize_t get_mm_cmdline(struct mm_struct *mm, char __user *buf,
                count -= got;
        }
 
-       free_page((unsigned long)page);
+       kfree(page);
        return len;
 }
 
@@ -908,7 +908,7 @@ static ssize_t mem_rw(struct file *file, char __user *buf,
        if (!mm)
                return 0;
 
-       page = (char *)__get_free_page(GFP_KERNEL);
+       page = kmalloc(PAGE_SIZE, GFP_KERNEL);
        if (!page)
                return -ENOMEM;
 
@@ -949,7 +949,7 @@ static ssize_t mem_rw(struct file *file, char __user *buf,
 
        mmput(mm);
 free:
-       free_page((unsigned long) page);
+       kfree(page);
        return copied;
 }
 
@@ -1016,7 +1016,7 @@ static ssize_t environ_read(struct file *file, char __user *buf,
        if (!mm || !mm->env_end)
                return 0;
 
-       page = (char *)__get_free_page(GFP_KERNEL);
+       page = kmalloc(PAGE_SIZE, GFP_KERNEL);
        if (!page)
                return -ENOMEM;
 
@@ -1062,7 +1062,7 @@ static ssize_t environ_read(struct file *file, char __user *buf,
        mmput(mm);
 
 free:
-       free_page((unsigned long) page);
+       kfree(page);
        return ret;
 }