From 7253eaba7b179db2e07e67c5b78d5f10b332291d Mon Sep 17 00:00:00 2001 From: Matt Fleming Date: Tue, 16 Oct 2012 15:58:07 +0100 Subject: [PATCH] efivarfs: Return an error if we fail to read a variable Instead of always returning 0 in efivarfs_file_read(), even when we fail to successfully read the variable, convert the EFI status to something meaningful and return that to the caller. This way the user will have some hint as to why the read failed. Acked-by: Jeremy Kerr Signed-off-by: Matt Fleming --- drivers/firmware/efivars.c | 62 ++++++++++++++++++++++---------------- 1 file changed, 36 insertions(+), 26 deletions(-) diff --git a/drivers/firmware/efivars.c b/drivers/firmware/efivars.c index a93e401c20a7..277e42616f0d 100644 --- a/drivers/firmware/efivars.c +++ b/drivers/firmware/efivars.c @@ -653,6 +653,36 @@ static int efivarfs_file_open(struct inode *inode, struct file *file) return 0; } +static int efi_status_to_err(efi_status_t status) +{ + int err; + + switch (status) { + case EFI_INVALID_PARAMETER: + err = -EINVAL; + break; + case EFI_OUT_OF_RESOURCES: + err = -ENOSPC; + break; + case EFI_DEVICE_ERROR: + err = -EIO; + break; + case EFI_WRITE_PROTECTED: + err = -EROFS; + break; + case EFI_SECURITY_VIOLATION: + err = -EACCES; + break; + case EFI_NOT_FOUND: + err = -ENOENT; + break; + default: + err = -EINVAL; + } + + return err; +} + static ssize_t efivarfs_file_write(struct file *file, const char __user *userbuf, size_t count, loff_t *ppos) { @@ -711,29 +741,7 @@ static ssize_t efivarfs_file_write(struct file *file, spin_unlock(&efivars->lock); kfree(data); - switch (status) { - case EFI_INVALID_PARAMETER: - count = -EINVAL; - break; - case EFI_OUT_OF_RESOURCES: - count = -ENOSPC; - break; - case EFI_DEVICE_ERROR: - count = -EIO; - break; - case EFI_WRITE_PROTECTED: - count = -EROFS; - break; - case EFI_SECURITY_VIOLATION: - count = -EACCES; - break; - case EFI_NOT_FOUND: - count = -ENOENT; - break; - default: - count = -EINVAL; - } - return count; + return efi_status_to_err(status); } /* @@ -791,12 +799,12 @@ static ssize_t efivarfs_file_read(struct file *file, char __user *userbuf, spin_unlock(&efivars->lock); if (status != EFI_BUFFER_TOO_SMALL) - return 0; + return efi_status_to_err(status); data = kmalloc(datasize + 4, GFP_KERNEL); if (!data) - return 0; + return -ENOMEM; spin_lock(&efivars->lock); status = efivars->ops->get_variable(var->var.VariableName, @@ -805,8 +813,10 @@ static ssize_t efivarfs_file_read(struct file *file, char __user *userbuf, (data + 4)); spin_unlock(&efivars->lock); - if (status != EFI_SUCCESS) + if (status != EFI_SUCCESS) { + size = efi_status_to_err(status); goto out_free; + } memcpy(data, &attributes, 4); size = simple_read_from_buffer(userbuf, count, ppos, -- 2.39.2