[PATCH v2] PowerPC: kernel: need return the related error code whenfailure occurs

From: Chen Gang
Date: Tue May 21 2013 - 05:21:46 EST



When error occurs, need return the related error code to let upper
caller know about it.

ppc_md.nvram_size() can return the error code (e.g. core99_nvram_size()
in 'arch/powerpc/platforms/powermac/nvram.c').

Also set ret value when only need it, so can save structions for normal
cases.

The original related patch: "f9ce299 [PATCH] powerpc: fix large nvram
access".


Signed-off-by: Chen Gang <gang.chen@xxxxxxxxxxx>
---
arch/powerpc/kernel/nvram_64.c | 20 ++++++++++++++------
1 files changed, 14 insertions(+), 6 deletions(-)

diff --git a/arch/powerpc/kernel/nvram_64.c b/arch/powerpc/kernel/nvram_64.c
index 48fbc2b..8213ee1 100644
--- a/arch/powerpc/kernel/nvram_64.c
+++ b/arch/powerpc/kernel/nvram_64.c
@@ -84,22 +84,30 @@ static ssize_t dev_nvram_read(struct file *file, char __user *buf,
char *tmp = NULL;
ssize_t size;

- ret = -ENODEV;
- if (!ppc_md.nvram_size)
+ if (!ppc_md.nvram_size) {
+ ret = -ENODEV;
goto out;
+ }

- ret = 0;
size = ppc_md.nvram_size();
- if (*ppos >= size || size < 0)
+ if (size < 0) {
+ ret = size;
+ goto out;
+ }
+
+ if (*ppos >= size) {
+ ret = 0;
goto out;
+ }

count = min_t(size_t, count, size - *ppos);
count = min(count, PAGE_SIZE);

- ret = -ENOMEM;
tmp = kmalloc(count, GFP_KERNEL);
- if (!tmp)
+ if (!tmp) {
+ ret = -ENOMEM;
goto out;
+ }

ret = ppc_md.nvram_read(tmp, count, ppos);
if (ret <= 0)
--
1.7.7.6
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