| Message ID | 201105242330.09491.rjw@sisk.pl (mailing list archive) |
|---|---|
| State | Superseded, archived |
| Headers | show |
On Tue, May 24, 2011 at 11:30:09PM +0200, Rafael J. Wysocki wrote: > On Tuesday, May 24, 2011, mark gross wrote: > > On Mon, May 23, 2011 at 09:54:52PM +0200, Rafael J. Wysocki wrote: > > > On Monday, May 23, 2011, mark gross wrote: > > > > On Mon, May 23, 2011 at 03:06:36PM +1000, Stephen Rothwell wrote: > > > > > Hi Rafael, > > > > > > > > > > After merging the suspend tree, today's linux-next build (i386 defconfig > > > > > among others) produced this warning: > > > > > > > > > > kernel/pm_qos_params.c: In function 'pm_qos_power_write': > > > > > kernel/pm_qos_params.c:420: warning: passing argument 3 of 'kstrtol' from incompatible pointer type > > > > > include/linux/kernel.h:210: note: expected 'long int *' but argument is of type 's32 *' > > > > > > > > > > Intreoduced by commit 365daa955e03 ("PM: Correct PM QOS's user mode > > > > > interface to work with ascii input per"). > > > > > > > > Gah! I'm sorry about that. > > > > > > > > attached is a fix. > > > > > > > > > > > > --mark > > > > > > > > signed-off-by:markgross <markgross@thegnar.org> > > > > > > > > > > > > > > > > From a8f0587b9ae598be5ca4c3cdda4e0ced6ca9baaf Mon Sep 17 00:00:00 2001 > > > > From: mgross <mgross@cr48> > > > > Date: Mon, 23 May 2011 07:14:09 -0700 > > > > Subject: [PATCH] clean up a compile time warning in the use of strict_strtol but that was > > > > passing an s32 * when it should be passing a long * > > > > > > > > --- > > > > kernel/pm_qos_params.c | 6 ++++-- > > > > 1 files changed, 4 insertions(+), 2 deletions(-) > > > > > > > > diff --git a/kernel/pm_qos_params.c b/kernel/pm_qos_params.c > > > > index d61ecf3..dd37c56 100644 > > > > --- a/kernel/pm_qos_params.c > > > > +++ b/kernel/pm_qos_params.c > > > > @@ -405,6 +405,7 @@ static ssize_t pm_qos_power_write(struct file *filp, const char __user *buf, > > > > size_t count, loff_t *f_pos) > > > > { > > > > s32 value; > > > > + long safe_int; > > > > int x; > > > > char ascii_value[11]; > > > > struct pm_qos_request_list *pm_qos_req; > > > > @@ -417,10 +418,11 @@ static ssize_t pm_qos_power_write(struct file *filp, const char __user *buf, > > > > ascii_value[count] = 0; > > > > if (copy_from_user(ascii_value, buf, count)) > > > > return -EFAULT; > > > > - if ((x=strict_strtol(ascii_value, 16, &value)) != 0){ > > > > - pr_debug("%s, 0x%x, 0x%x\n",ascii_value, value, x); > > > > + if ((x=strict_strtol(ascii_value, 16, &safe_int)) != 0){ > > > > + pr_debug("%s, 0x%lx, 0x%x\n",ascii_value, safe_int, x); > > > > return -EINVAL; > > > > } > > > > + value = (s32) safe_int; > > > > > > Well, this doesn't seem quite right. > > > > > > > } else > > > > return -EINVAL; > > > > > > Besides, if count == 11, there we'll write beyond ascii_value[], right? > > > > right. That is a bug. > > > > > > > > What about the appended patch instead of your original one? > > Thank you! > > > > > Rafael > > > > > > > > > --- > > > From: mark gross <markgross@thegnar.org> > > > Subject: PM: Correct PM QOS's user mode interface to work with ascii input per > > > > > > What is in the kernel docs. Writing a string to the ABI from user mode > > > comes in 2 flavors. One with and one without a '\n' at the end. This > > > change accepts both. > > > > > > # echo 0x12345678 > /dev/cpu_dma_latency > > > > > > and > > > > > > # echo -n 0x12345678 > /dev/cpu_dma_latency > > > > > > now both work. > > > > > > [rjw: Fixed up array bounds checking and type casting.] > > > > > > Signed-off-by: mark gross <markgross@thegnar.org> > > > Acked-by: Simon Horman <horms@verge.net.au> > > > Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> > > > --- > > > kernel/pm_qos_params.c | 25 ++++++++++++++++--------- > > > 1 file changed, 16 insertions(+), 9 deletions(-) > > > > > > Index: linux-2.6/kernel/pm_qos_params.c > > > =================================================================== > > > --- linux-2.6.orig/kernel/pm_qos_params.c > > > +++ linux-2.6/kernel/pm_qos_params.c > > > @@ -40,6 +40,7 @@ > > > #include <linux/string.h> > > > #include <linux/platform_device.h> > > > #include <linux/init.h> > > > +#include <linux/kernel.h> > > > > > > #include <linux/uaccess.h> > > > > > > @@ -404,24 +405,30 @@ static ssize_t pm_qos_power_write(struct > > > size_t count, loff_t *f_pos) > > > { > > > s32 value; > > > - int x; > > > char ascii_value[11]; > > > struct pm_qos_request_list *pm_qos_req; > > > > > > if (count == sizeof(s32)) { > > > if (copy_from_user(&value, buf, sizeof(s32))) > > > return -EFAULT; > > > - } else if (count == 11) { /* len('0x12345678/0') */ > > > - if (copy_from_user(ascii_value, buf, 11)) > > > + } else if (count >= 10) { /* '0x12345678' or '0x12345678\n'*/ > > Did you mean <= 11 here? I know that Alan Stern wanted to see the ABI > > adjusted to accept shorter hex string that the full 10 char string. > > > > FWIW I'm ok with doing that. > > > > > + unsigned long int ulval; > > > + int ret; > > > + > > > + count = 10; > > > > I kind of wanted to return an error to the user if they violate the > > documented format for the hex string. With this code you get a silent > > truncation of the lower digits if the string is "0x123456789abcdef" > > That's correct, but with the previous code there will be a truncation > is "echo -n 0x123456789". If we don't want that, we should check if the > last character is a '\n'. > > > > + ascii_value[count] = 0; > > > + if (copy_from_user(ascii_value, buf, count)) > > > return -EFAULT; > > > - if (strlen(ascii_value) != 10) > > > - return -EINVAL; > > > - x = sscanf(ascii_value, "%x", &value); > > > - if (x != 1) > > > + > > > + ret = strict_strtoul(ascii_value, 16, &ulval); > > > + if (ret){ > > > + pr_debug("%s, 0x%lx, 0x%x\n", ascii_value, ulval, ret); > > > return -EINVAL; > > > - pr_debug("%s, %d, 0x%x\n", ascii_value, x, value); > > > - } else > > > + } > > > + value = (s32)lower_32_bits(ulval); > > This shouldn't be needed if you are constrained to a hex format of > > "0x12345678" but this is more readable. lower_32_bits is a good idea. > > OK > > Appended is another patch that adds the '\n' check and reworks the code > a bit (so that it will accept strings like "0x1" too). > > Thanks, > Rafael > > > --- > From: Rafael J. Wysocki <rjw@sisk.pl> > Subject: PM: Fix PM QOS's user mode interface to work with ASCII input > > Make pm_qos_power_write() accept values passed to it in the ASCII hex > format either with or without an ending newline. > > Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> > --- > kernel/pm_qos_params.c | 33 +++++++++++++++++++++++---------- > 1 file changed, 23 insertions(+), 10 deletions(-) > > Index: linux-2.6/kernel/pm_qos_params.c > =================================================================== > --- linux-2.6.orig/kernel/pm_qos_params.c > +++ linux-2.6/kernel/pm_qos_params.c > @@ -40,6 +40,7 @@ > #include <linux/string.h> > #include <linux/platform_device.h> > #include <linux/init.h> > +#include <linux/kernel.h> > > #include <linux/uaccess.h> > > @@ -404,24 +405,36 @@ static ssize_t pm_qos_power_write(struct > size_t count, loff_t *f_pos) > { > s32 value; > - int x; > - char ascii_value[11]; > struct pm_qos_request_list *pm_qos_req; > > if (count == sizeof(s32)) { > if (copy_from_user(&value, buf, sizeof(s32))) > return -EFAULT; > - } else if (count == 11) { /* len('0x12345678/0') */ > - if (copy_from_user(ascii_value, buf, 11)) > + } else if (count <= 11) { /* ASCII perhaps? */ > + char ascii_value[11]; > + unsigned long int ulval; > + int ret; > + > + if (copy_from_user(ascii_value, buf, count)) > return -EFAULT; > - if (strlen(ascii_value) != 10) > - return -EINVAL; > - x = sscanf(ascii_value, "%x", &value); > - if (x != 1) > + > + if (count > 10) { > + if (ascii_value[10] == '\n') > + ascii_value[10] = '\0'; > + else > + return -EINVAL; > + } else { > + ascii_value[count] = '\0'; > + } > + ret = strict_strtoul(ascii_value, 16, &ulval); > + if (ret) { > + pr_debug("%s, 0x%lx, 0x%x\n", ascii_value, ulval, ret); > return -EINVAL; > - pr_debug("%s, %d, 0x%x\n", ascii_value, x, value); > - } else > + } > + value = (s32)lower_32_bits(ulval); > + } else { > return -EINVAL; > + } > > pm_qos_req = filp->private_data; > pm_qos_update_request(pm_qos_req, value); looks good to me. Acked-by: markgross <markgross@thegnar.org>
Index: linux-2.6/kernel/pm_qos_params.c =================================================================== --- linux-2.6.orig/kernel/pm_qos_params.c +++ linux-2.6/kernel/pm_qos_params.c @@ -40,6 +40,7 @@ #include <linux/string.h> #include <linux/platform_device.h> #include <linux/init.h> +#include <linux/kernel.h> #include <linux/uaccess.h> @@ -404,24 +405,36 @@ static ssize_t pm_qos_power_write(struct size_t count, loff_t *f_pos) { s32 value; - int x; - char ascii_value[11]; struct pm_qos_request_list *pm_qos_req; if (count == sizeof(s32)) { if (copy_from_user(&value, buf, sizeof(s32))) return -EFAULT; - } else if (count == 11) { /* len('0x12345678/0') */ - if (copy_from_user(ascii_value, buf, 11)) + } else if (count <= 11) { /* ASCII perhaps? */ + char ascii_value[11]; + unsigned long int ulval; + int ret; + + if (copy_from_user(ascii_value, buf, count)) return -EFAULT; - if (strlen(ascii_value) != 10) - return -EINVAL; - x = sscanf(ascii_value, "%x", &value); - if (x != 1) + + if (count > 10) { + if (ascii_value[10] == '\n') + ascii_value[10] = '\0'; + else + return -EINVAL; + } else { + ascii_value[count] = '\0'; + } + ret = strict_strtoul(ascii_value, 16, &ulval); + if (ret) { + pr_debug("%s, 0x%lx, 0x%x\n", ascii_value, ulval, ret); return -EINVAL; - pr_debug("%s, %d, 0x%x\n", ascii_value, x, value); - } else + } + value = (s32)lower_32_bits(ulval); + } else { return -EINVAL; + } pm_qos_req = filp->private_data; pm_qos_update_request(pm_qos_req, value);