Re: [PATCH] arch:powerpc simple_write_to_buffer return check
From: Christophe Leroy <hidden>
Date: 2021-02-05 07:22:14
Also in:
lkml
Please provide some description of the change. And please clarify the patch subject, because as far as I can see, the return is already checked allthough the check seams wrong. Le 04/02/2021 à 19:16, Mayank Suman a écrit :
quoted hunk ↗ jump to hunk
Signed-off-by: Mayank Suman <redacted> --- arch/powerpc/kernel/eeh.c | 8 ++++---- arch/powerpc/platforms/powernv/eeh-powernv.c | 4 ++-- 2 files changed, 6 insertions(+), 6 deletions(-)diff --git a/arch/powerpc/kernel/eeh.c b/arch/powerpc/kernel/eeh.c index 813713c9120c..2dbe1558a71f 100644 --- a/arch/powerpc/kernel/eeh.c +++ b/arch/powerpc/kernel/eeh.c@@ -1628,8 +1628,8 @@ static ssize_t eeh_force_recover_write(struct file *filp, char buf[20]; int ret; - ret = simple_write_to_buffer(buf, sizeof(buf), ppos, user_buf, count); - if (!ret) + ret = simple_write_to_buffer(buf, sizeof(buf)-1, ppos, user_buf, count); + if (ret <= 0) > return -EFAULT;
Why return -EFAULT when the function has returned -EINVAL ? And why is it -EFAULT when ret is 0 ? EFAULT means error accessing memory.
quoted hunk ↗ jump to hunk
/*@@ -1696,7 +1696,7 @@ static ssize_t eeh_dev_check_write(struct file *filp, memset(buf, 0, sizeof(buf)); ret = simple_write_to_buffer(buf, sizeof(buf)-1, ppos, user_buf, count); - if (!ret) + if (ret <= 0) return -EFAULT; ret = sscanf(buf, "%x:%x:%x.%x", &domain, &bus, &dev, &fn);@@ -1836,7 +1836,7 @@ static ssize_t eeh_dev_break_write(struct file *filp, memset(buf, 0, sizeof(buf)); ret = simple_write_to_buffer(buf, sizeof(buf)-1, ppos, user_buf, count); - if (!ret) + if (ret <= 0) return -EFAULT; ret = sscanf(buf, "%x:%x:%x.%x", &domain, &bus, &dev, &fn);diff --git a/arch/powerpc/platforms/powernv/eeh-powernv.c b/arch/powerpc/platforms/powernv/eeh-powernv.c index 89e22c460ebf..36ed2b8f7375 100644 --- a/arch/powerpc/platforms/powernv/eeh-powernv.c +++ b/arch/powerpc/platforms/powernv/eeh-powernv.c@@ -76,8 +76,8 @@ static ssize_t pnv_eeh_ei_write(struct file *filp, return -ENXIO; /* Copy over argument buffer */ - ret = simple_write_to_buffer(buf, sizeof(buf), ppos, user_buf, count); - if (!ret) + ret = simple_write_to_buffer(buf, sizeof(buf)-1, ppos, user_buf, count); + if (ret <= 0) return -EFAULT; /* Retrieve parameters */