[PATCH 7/8] misc: eeprom: at25: move eeprom boundary checks to mem_read/mem_write

From: Vladimir Zapolskiy
Date: Sun Jul 26 2015 - 17:29:17 EST


The sanity checks for overflow over eeprom size are not needed, if
eeprom is accessed from userspace over sysfs interface, because this
is handled by fs/sysfs/file.c, however in case of reading or writing
within the kernel it might be still reasonable to pass the check.

The change moves these checks from shared at25_ee_read() and
at25_ee_write() directly to at25_mem_read() and at25_mem_write(), no
functional change.

Signed-off-by: Vladimir Zapolskiy <vz@xxxxxxxxx>
---
drivers/misc/eeprom/at25.c | 28 ++++++++++++++--------------
1 file changed, 14 insertions(+), 14 deletions(-)

diff --git a/drivers/misc/eeprom/at25.c b/drivers/misc/eeprom/at25.c
index 0a1af93..c4f5c4a 100644
--- a/drivers/misc/eeprom/at25.c
+++ b/drivers/misc/eeprom/at25.c
@@ -77,13 +77,6 @@ at25_ee_read(
struct spi_message m;
u8 instr;

- if (unlikely(offset >= at25->bin.size))
- return 0;
- if ((offset + count) > at25->bin.size)
- count = at25->bin.size - offset;
- if (unlikely(!count))
- return count;
-
cp = command;

instr = AT25_READ;
@@ -155,13 +148,6 @@ at25_ee_write(struct at25_data *at25, const char *buf, loff_t off,
unsigned buf_size;
u8 *bounce;

- if (unlikely(off >= at25->bin.size))
- return -EFBIG;
- if ((off + count) > at25->bin.size)
- count = at25->bin.size - off;
- if (unlikely(!count))
- return count;
-
/* Temp buffer starts with command and address */
buf_size = at25->chip.page_size;
if (buf_size > io_limit)
@@ -288,6 +274,13 @@ static ssize_t at25_mem_read(struct memory_accessor *mem, char *buf,
{
struct at25_data *at25 = container_of(mem, struct at25_data, mem);

+ if (unlikely(offset >= at25->bin.size))
+ return 0;
+ if ((offset + count) > at25->bin.size)
+ count = at25->bin.size - offset;
+ if (unlikely(!count))
+ return count;
+
return at25_ee_read(at25, buf, offset, count);
}

@@ -296,7 +289,13 @@ static ssize_t at25_mem_write(struct memory_accessor *mem, const char *buf,
{
struct at25_data *at25 = container_of(mem, struct at25_data, mem);

+ if (unlikely(offset >= at25->bin.size))
+ return -EFBIG;
+ if ((offset + count) > at25->bin.size)
+ count = at25->bin.size - offset;
+ if (unlikely(!count))
+ return count;
+
return at25_ee_write(at25, buf, offset, count);
}

--
2.1.4

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