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authorLinus Torvalds <torvalds@linux-foundation.org>2023-09-01 09:53:54 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2023-09-01 09:53:54 -0700
commit1c9f8dff62d85ce00b0e99f774a84bd783af7cac (patch)
treecd1fcbc26856dfd1981ef1f81396eb67dde993bd /fs/debugfs
parent28a4f91f5f251689c69155bc6a0b1afc9916c874 (diff)
parent704e2c6107f1a5353a1038bac137dda0df2a6dd0 (diff)
Merge tag 'char-misc-6.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc
Pull char/misc driver updates from Greg KH: "Here is the big set of char/misc and other small driver subsystem changes for 6.6-rc1. Stuff all over the place here, lots of driver updates and changes and new additions. Short summary is: - new IIO drivers and updates - Interconnect driver updates - fpga driver updates and additions - fsi driver updates - mei driver updates - coresight driver updates - nvmem driver updates - counter driver updates - lots of smaller misc and char driver updates and additions All of these have been in linux-next for a long time with no reported problems" * tag 'char-misc-6.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (267 commits) nvmem: core: Notify when a new layout is registered nvmem: core: Do not open-code existing functions nvmem: core: Return NULL when no nvmem layout is found nvmem: core: Create all cells before adding the nvmem device nvmem: u-boot-env:: Replace zero-length array with DECLARE_FLEX_ARRAY() helper nvmem: sec-qfprom: Add Qualcomm secure QFPROM support dt-bindings: nvmem: sec-qfprom: Add bindings for secure qfprom dt-bindings: nvmem: Add compatible for QCM2290 nvmem: Kconfig: Fix typo "drive" -> "driver" nvmem: Explicitly include correct DT includes nvmem: add new NXP QorIQ eFuse driver dt-bindings: nvmem: Add t1023-sfp efuse support dt-bindings: nvmem: qfprom: Add compatible for MSM8226 nvmem: uniphier: Use devm_platform_get_and_ioremap_resource() nvmem: qfprom: do some cleanup nvmem: stm32-romem: Use devm_platform_get_and_ioremap_resource() nvmem: rockchip-efuse: Use devm_platform_get_and_ioremap_resource() nvmem: meson-mx-efuse: Convert to devm_platform_ioremap_resource() nvmem: lpc18xx_otp: Convert to devm_platform_ioremap_resource() nvmem: brcm_nvram: Use devm_platform_get_and_ioremap_resource() ...
Diffstat (limited to 'fs/debugfs')
-rw-r--r--fs/debugfs/file.c48
1 files changed, 46 insertions, 2 deletions
diff --git a/fs/debugfs/file.c b/fs/debugfs/file.c
index b7711888dd17..87b3753aa4b1 100644
--- a/fs/debugfs/file.c
+++ b/fs/debugfs/file.c
@@ -904,8 +904,52 @@ EXPORT_SYMBOL_GPL(debugfs_create_str);
static ssize_t debugfs_write_file_str(struct file *file, const char __user *user_buf,
size_t count, loff_t *ppos)
{
- /* This is really only for read-only strings */
- return -EINVAL;
+ struct dentry *dentry = F_DENTRY(file);
+ char *old, *new = NULL;
+ int pos = *ppos;
+ int r;
+
+ r = debugfs_file_get(dentry);
+ if (unlikely(r))
+ return r;
+
+ old = *(char **)file->private_data;
+
+ /* only allow strict concatenation */
+ r = -EINVAL;
+ if (pos && pos != strlen(old))
+ goto error;
+
+ r = -E2BIG;
+ if (pos + count + 1 > PAGE_SIZE)
+ goto error;
+
+ r = -ENOMEM;
+ new = kmalloc(pos + count + 1, GFP_KERNEL);
+ if (!new)
+ goto error;
+
+ if (pos)
+ memcpy(new, old, pos);
+
+ r = -EFAULT;
+ if (copy_from_user(new + pos, user_buf, count))
+ goto error;
+
+ new[pos + count] = '\0';
+ strim(new);
+
+ rcu_assign_pointer(*(char **)file->private_data, new);
+ synchronize_rcu();
+ kfree(old);
+
+ debugfs_file_put(dentry);
+ return count;
+
+error:
+ kfree(new);
+ debugfs_file_put(dentry);
+ return r;
}
static const struct file_operations fops_str = {