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'). And when '*ppos >= size', need return -ESPIPE (Illegal seek) The original related patch: "f9ce299 [PATCH] powerpc: fix large nvram access" Signed-off-by: Chen Gang <gang.c...@asianux.com> --- arch/powerpc/kernel/nvram_64.c | 9 +++++++-- 1 files changed, 7 insertions(+), 2 deletions(-) diff --git a/arch/powerpc/kernel/nvram_64.c b/arch/powerpc/kernel/nvram_64.c index 48fbc2b..db2a636 100644 --- a/arch/powerpc/kernel/nvram_64.c +++ b/arch/powerpc/kernel/nvram_64.c @@ -88,10 +88,15 @@ static ssize_t dev_nvram_read(struct file *file, char __user *buf, if (!ppc_md.nvram_size) 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 = -ESPIPE; + goto out; + } count = min_t(size_t, count, size - *ppos); count = min(count, PAGE_SIZE); -- 1.7.7.6 _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev