| Message ID | 20240104101253.25896-2-petre.rodan@subdimension.ro (mailing list archive) |
|---|---|
| State | Changes Requested |
| Headers | show |
| Series | tools: iio: fix iio_generic_buffer | expand |
On Thu, 4 Jan 2024 12:12:45 +0200 Petre Rodan <petre.rodan@subdimension.ro> wrote: > Fix code flow problem and floating point exception caused by improper > directory stream positioning. > > Fixes: <e58537ccce733> ("staging: iio: update example application.") > Signed-off-by: Petre Rodan <petre.rodan@subdimension.ro> Hi Petre, This doesn't really explain 'why' seeekdir(dp, 0) is wrong. My assumption is that telldir() would not have returned 0 on this particular system? Could you confirm that and update the message to explain why seekdir(dp, 0) is not equivalent to rewinddir(dp). Thanks, Jonathan > --- > tools/iio/iio_utils.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/tools/iio/iio_utils.c b/tools/iio/iio_utils.c > index 6a00a6eecaef..c5c5082cb24e 100644 > --- a/tools/iio/iio_utils.c > +++ b/tools/iio/iio_utils.c > @@ -376,7 +376,7 @@ int build_channel_array(const char *device_dir, int buffer_idx, > goto error_close_dir; > } > > - seekdir(dp, 0); > + rewinddir(dp); > while (ent = readdir(dp), ent) { > if (strcmp(ent->d_name + strlen(ent->d_name) - strlen("_en"), > "_en") == 0) { > -- > 2.41.0 >
Hi Jonathan, On Sun, Jan 07, 2024 at 03:53:33PM +0000, Jonathan Cameron wrote: > On Thu, 4 Jan 2024 12:12:45 +0200 > Petre Rodan <petre.rodan@subdimension.ro> wrote: > > > Fix code flow problem and floating point exception caused by improper > > directory stream positioning. > > > > Fixes: <e58537ccce733> ("staging: iio: update example application.") > > Signed-off-by: Petre Rodan <petre.rodan@subdimension.ro> > Hi Petre, > > This doesn't really explain 'why' seeekdir(dp, 0) is wrong. > My assumption is that telldir() would not have returned 0 on this particular > system? Could you confirm that and update the message to explain why > seekdir(dp, 0) is not equivalent to rewinddir(dp). it looks like there is a 32-bit specific bug in one of the glibc patches that the stable Gentoo Linux is using [1]. telldir returns (u32)(-1) if seekdir is used which ends up in a floating point exception. it so happens that the rewinddir() function (which is equivalent) works correctly. so it is a fix for Gentoo users and should not impact anyone else. [1] https://sourceware.org/bugzilla/show_bug.cgi?id=31212 my very best regards, peter > Thanks, > > Jonathan > > > --- > > tools/iio/iio_utils.c | 2 +- > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > diff --git a/tools/iio/iio_utils.c b/tools/iio/iio_utils.c > > index 6a00a6eecaef..c5c5082cb24e 100644 > > --- a/tools/iio/iio_utils.c > > +++ b/tools/iio/iio_utils.c > > @@ -376,7 +376,7 @@ int build_channel_array(const char *device_dir, int buffer_idx, > > goto error_close_dir; > > } > > > > - seekdir(dp, 0); > > + rewinddir(dp); > > while (ent = readdir(dp), ent) { > > if (strcmp(ent->d_name + strlen(ent->d_name) - strlen("_en"), > > "_en") == 0) { > > -- > > 2.41.0
On Sun, 7 Jan 2024 18:28:52 +0200 Petre Rodan <petre.rodan@subdimension.ro> wrote: > Hi Jonathan, > > On Sun, Jan 07, 2024 at 03:53:33PM +0000, Jonathan Cameron wrote: > > On Thu, 4 Jan 2024 12:12:45 +0200 > > Petre Rodan <petre.rodan@subdimension.ro> wrote: > > > > > Fix code flow problem and floating point exception caused by improper > > > directory stream positioning. > > > > > > Fixes: <e58537ccce733> ("staging: iio: update example application.") > > > Signed-off-by: Petre Rodan <petre.rodan@subdimension.ro> > > Hi Petre, > > > > This doesn't really explain 'why' seeekdir(dp, 0) is wrong. > > My assumption is that telldir() would not have returned 0 on this particular > > system? Could you confirm that and update the message to explain why > > seekdir(dp, 0) is not equivalent to rewinddir(dp). > > it looks like there is a 32-bit specific bug in one of the glibc patches that > the stable Gentoo Linux is using [1]. telldir returns (u32)(-1) if seekdir is > used which ends up in a floating point exception. > > it so happens that the rewinddir() function (which is equivalent) works > correctly. so it is a fix for Gentoo users and should not impact anyone else. > > [1] https://sourceware.org/bugzilla/show_bug.cgi?id=31212 > > my very best regards, > peter I'd be happy to take the same change as a cleanup if you want to resubmit it with a different patch description. Thanks, Jonathan > > > Thanks, > > > > Jonathan > > > > > --- > > > tools/iio/iio_utils.c | 2 +- > > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > > > diff --git a/tools/iio/iio_utils.c b/tools/iio/iio_utils.c > > > index 6a00a6eecaef..c5c5082cb24e 100644 > > > --- a/tools/iio/iio_utils.c > > > +++ b/tools/iio/iio_utils.c > > > @@ -376,7 +376,7 @@ int build_channel_array(const char *device_dir, int buffer_idx, > > > goto error_close_dir; > > > } > > > > > > - seekdir(dp, 0); > > > + rewinddir(dp); > > > while (ent = readdir(dp), ent) { > > > if (strcmp(ent->d_name + strlen(ent->d_name) - strlen("_en"), > > > "_en") == 0) { > > > -- > > > 2.41.0
Hi Jonathan, On Sun, Jan 07, 2024 at 05:00:26PM +0000, Jonathan Cameron wrote: > > On Sun, Jan 07, 2024 at 03:53:33PM +0000, Jonathan Cameron wrote: > > > On Thu, 4 Jan 2024 12:12:45 +0200 > > > Petre Rodan <petre.rodan@subdimension.ro> wrote: > > > > > > > Fix code flow problem and floating point exception caused by improper > > > > directory stream positioning. > > > > > > > > Fixes: <e58537ccce733> ("staging: iio: update example application.") > > > > Signed-off-by: Petre Rodan <petre.rodan@subdimension.ro> > > > Hi Petre, > > > > > > This doesn't really explain 'why' seeekdir(dp, 0) is wrong. > > > My assumption is that telldir() would not have returned 0 on this particular > > > system? Could you confirm that and update the message to explain why > > > seekdir(dp, 0) is not equivalent to rewinddir(dp). > > > > it looks like there is a 32-bit specific bug in one of the glibc patches that > > the stable Gentoo Linux is using [1]. telldir returns (u32)(-1) if seekdir is > > used which ends up in a floating point exception. > > > > it so happens that the rewinddir() function (which is equivalent) works > > correctly. so it is a fix for Gentoo users and should not impact anyone else. > > > > [1] https://sourceware.org/bugzilla/show_bug.cgi?id=31212 > > > > my very best regards, > > peter > > I'd be happy to take the same change as a cleanup if you want to resubmit it > with a different patch description. sure, I will resubmit it, but tomorrow morning. best regards, peter
diff --git a/tools/iio/iio_utils.c b/tools/iio/iio_utils.c index 6a00a6eecaef..c5c5082cb24e 100644 --- a/tools/iio/iio_utils.c +++ b/tools/iio/iio_utils.c @@ -376,7 +376,7 @@ int build_channel_array(const char *device_dir, int buffer_idx, goto error_close_dir; } - seekdir(dp, 0); + rewinddir(dp); while (ent = readdir(dp), ent) { if (strcmp(ent->d_name + strlen(ent->d_name) - strlen("_en"), "_en") == 0) {
Fix code flow problem and floating point exception caused by improper directory stream positioning. Fixes: <e58537ccce733> ("staging: iio: update example application.") Signed-off-by: Petre Rodan <petre.rodan@subdimension.ro> --- tools/iio/iio_utils.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) -- 2.41.0