| Message ID | 20240731213221.2523989-3-matthew.brost@intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Faster devcoredump and fixes | expand |
-----Original Message----- From: Intel-xe <intel-xe-bounces@lists.freedesktop.org> On Behalf Of Matthew Brost Sent: Wednesday, July 31, 2024 2:32 PM To: intel-xe@lists.freedesktop.org; dri-devel@lists.freedesktop.org Cc: maarten.lankhorst@linux.intel.com; Vivi, Rodrigo <rodrigo.vivi@intel.com> Subject: [PATCH v4 2/3] drm/printer: Allow NULL data in devcoredump printer > > Useful to determine size of devcoreump before writing it out. > > Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com> > Signed-off-by: Matthew Brost <matthew.brost@intel.com> It seems this patch prevents us from copying strings into the data field if the data field hasn't been initialized. I'm not certain if it could ever be uninitialized at this point, but I recognize it as good practice to check just in case regardless. Reviewed-by: Jonathan Cavitt <jonathan.cavitt@intel.com> -Jonathan Cavitt > --- > drivers/gpu/drm/drm_print.c | 13 ++++++++----- > 1 file changed, 8 insertions(+), 5 deletions(-) > > diff --git a/drivers/gpu/drm/drm_print.c b/drivers/gpu/drm/drm_print.c > index cf24dfdeb6b2..a1a4de9f9c44 100644 > --- a/drivers/gpu/drm/drm_print.c > +++ b/drivers/gpu/drm/drm_print.c > @@ -100,8 +100,9 @@ void __drm_puts_coredump(struct drm_printer *p, const char *str) > copy = iterator->remain; > > /* Copy out the bit of the string that we need */ > - memcpy(iterator->data, > - str + (iterator->start - iterator->offset), copy); > + if (iterator->data) > + memcpy(iterator->data, > + str + (iterator->start - iterator->offset), copy); > > iterator->offset = iterator->start + copy; > iterator->remain -= copy; > @@ -110,7 +111,8 @@ void __drm_puts_coredump(struct drm_printer *p, const char *str) > > len = min_t(ssize_t, strlen(str), iterator->remain); > > - memcpy(iterator->data + pos, str, len); > + if (iterator->data) > + memcpy(iterator->data + pos, str, len); > > iterator->offset += len; > iterator->remain -= len; > @@ -140,8 +142,9 @@ void __drm_printfn_coredump(struct drm_printer *p, struct va_format *vaf) > if ((iterator->offset >= iterator->start) && (len < iterator->remain)) { > ssize_t pos = iterator->offset - iterator->start; > > - snprintf(((char *) iterator->data) + pos, > - iterator->remain, "%pV", vaf); > + if (iterator->data) > + snprintf(((char *) iterator->data) + pos, > + iterator->remain, "%pV", vaf); > > iterator->offset += len; > iterator->remain -= len; > -- > 2.34.1 > >
On Wed, Jul 31, 2024 at 04:22:03PM -0600, Cavitt, Jonathan wrote: > -----Original Message----- > From: Intel-xe <intel-xe-bounces@lists.freedesktop.org> On Behalf Of Matthew Brost > Sent: Wednesday, July 31, 2024 2:32 PM > To: intel-xe@lists.freedesktop.org; dri-devel@lists.freedesktop.org > Cc: maarten.lankhorst@linux.intel.com; Vivi, Rodrigo <rodrigo.vivi@intel.com> > Subject: [PATCH v4 2/3] drm/printer: Allow NULL data in devcoredump printer > > > > Useful to determine size of devcoreump before writing it out. > > > > Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com> > > Signed-off-by: Matthew Brost <matthew.brost@intel.com> > > It seems this patch prevents us from copying strings into the data field if the data > field hasn't been initialized. I'm not certain if it could ever be uninitialized at this > point, but I recognize it as good practice to check just in case regardless. > That's not the intent. The intent to call the print functions with NULL data so the printer can calculate the size of buffer required to print out all the devcoredump data. Matt > Reviewed-by: Jonathan Cavitt <jonathan.cavitt@intel.com> > -Jonathan Cavitt > > > --- > > drivers/gpu/drm/drm_print.c | 13 ++++++++----- > > 1 file changed, 8 insertions(+), 5 deletions(-) > > > > diff --git a/drivers/gpu/drm/drm_print.c b/drivers/gpu/drm/drm_print.c > > index cf24dfdeb6b2..a1a4de9f9c44 100644 > > --- a/drivers/gpu/drm/drm_print.c > > +++ b/drivers/gpu/drm/drm_print.c > > @@ -100,8 +100,9 @@ void __drm_puts_coredump(struct drm_printer *p, const char *str) > > copy = iterator->remain; > > > > /* Copy out the bit of the string that we need */ > > - memcpy(iterator->data, > > - str + (iterator->start - iterator->offset), copy); > > + if (iterator->data) > > + memcpy(iterator->data, > > + str + (iterator->start - iterator->offset), copy); > > > > iterator->offset = iterator->start + copy; > > iterator->remain -= copy; > > @@ -110,7 +111,8 @@ void __drm_puts_coredump(struct drm_printer *p, const char *str) > > > > len = min_t(ssize_t, strlen(str), iterator->remain); > > > > - memcpy(iterator->data + pos, str, len); > > + if (iterator->data) > > + memcpy(iterator->data + pos, str, len); > > > > iterator->offset += len; > > iterator->remain -= len; > > @@ -140,8 +142,9 @@ void __drm_printfn_coredump(struct drm_printer *p, struct va_format *vaf) > > if ((iterator->offset >= iterator->start) && (len < iterator->remain)) { > > ssize_t pos = iterator->offset - iterator->start; > > > > - snprintf(((char *) iterator->data) + pos, > > - iterator->remain, "%pV", vaf); > > + if (iterator->data) > > + snprintf(((char *) iterator->data) + pos, > > + iterator->remain, "%pV", vaf); > > > > iterator->offset += len; > > iterator->remain -= len; > > -- > > 2.34.1 > > > >
On Wed, 31 Jul 2024, Matthew Brost <matthew.brost@intel.com> wrote: > Useful to determine size of devcoreump before writing it out. I find it useful to have this special case documented, with an example, so it's easier to see how handy this really is. BR, Jani. > > Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com> > Signed-off-by: Matthew Brost <matthew.brost@intel.com> > --- > drivers/gpu/drm/drm_print.c | 13 ++++++++----- > 1 file changed, 8 insertions(+), 5 deletions(-) > > diff --git a/drivers/gpu/drm/drm_print.c b/drivers/gpu/drm/drm_print.c > index cf24dfdeb6b2..a1a4de9f9c44 100644 > --- a/drivers/gpu/drm/drm_print.c > +++ b/drivers/gpu/drm/drm_print.c > @@ -100,8 +100,9 @@ void __drm_puts_coredump(struct drm_printer *p, const char *str) > copy = iterator->remain; > > /* Copy out the bit of the string that we need */ > - memcpy(iterator->data, > - str + (iterator->start - iterator->offset), copy); > + if (iterator->data) > + memcpy(iterator->data, > + str + (iterator->start - iterator->offset), copy); > > iterator->offset = iterator->start + copy; > iterator->remain -= copy; > @@ -110,7 +111,8 @@ void __drm_puts_coredump(struct drm_printer *p, const char *str) > > len = min_t(ssize_t, strlen(str), iterator->remain); > > - memcpy(iterator->data + pos, str, len); > + if (iterator->data) > + memcpy(iterator->data + pos, str, len); > > iterator->offset += len; > iterator->remain -= len; > @@ -140,8 +142,9 @@ void __drm_printfn_coredump(struct drm_printer *p, struct va_format *vaf) > if ((iterator->offset >= iterator->start) && (len < iterator->remain)) { > ssize_t pos = iterator->offset - iterator->start; > > - snprintf(((char *) iterator->data) + pos, > - iterator->remain, "%pV", vaf); > + if (iterator->data) > + snprintf(((char *) iterator->data) + pos, > + iterator->remain, "%pV", vaf); > > iterator->offset += len; > iterator->remain -= len;
-----Original Message----- From: Brost, Matthew <matthew.brost@intel.com> Sent: Wednesday, July 31, 2024 5:03 PM To: Cavitt, Jonathan <jonathan.cavitt@intel.com> Cc: intel-xe@lists.freedesktop.org; dri-devel@lists.freedesktop.org; maarten.lankhorst@linux.intel.com; Vivi, Rodrigo <rodrigo.vivi@intel.com> Subject: Re: [PATCH v4 2/3] drm/printer: Allow NULL data in devcoredump printer > > On Wed, Jul 31, 2024 at 04:22:03PM -0600, Cavitt, Jonathan wrote: > > -----Original Message----- > > From: Intel-xe <intel-xe-bounces@lists.freedesktop.org> On Behalf Of Matthew Brost > > Sent: Wednesday, July 31, 2024 2:32 PM > > To: intel-xe@lists.freedesktop.org; dri-devel@lists.freedesktop.org > > Cc: maarten.lankhorst@linux.intel.com; Vivi, Rodrigo <rodrigo.vivi@intel.com> > > Subject: [PATCH v4 2/3] drm/printer: Allow NULL data in devcoredump printer > > > > > > Useful to determine size of devcoreump before writing it out. > > > > > > Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com> > > > Signed-off-by: Matthew Brost <matthew.brost@intel.com> > > > > It seems this patch prevents us from copying strings into the data field if the data > > field hasn't been initialized. I'm not certain if it could ever be uninitialized at this > > point, but I recognize it as good practice to check just in case regardless. > > > > That's not the intent. The intent to call the print functions with NULL > data so the printer can calculate the size of buffer required to print > out all the devcoredump data. So if iterator->data is NULL, you want to NOT copy into it? -Jonathan Cavitt > > Matt > > > Reviewed-by: Jonathan Cavitt <jonathan.cavitt@intel.com> > > -Jonathan Cavitt > > > > > --- > > > drivers/gpu/drm/drm_print.c | 13 ++++++++----- > > > 1 file changed, 8 insertions(+), 5 deletions(-) > > > > > > diff --git a/drivers/gpu/drm/drm_print.c b/drivers/gpu/drm/drm_print.c > > > index cf24dfdeb6b2..a1a4de9f9c44 100644 > > > --- a/drivers/gpu/drm/drm_print.c > > > +++ b/drivers/gpu/drm/drm_print.c > > > @@ -100,8 +100,9 @@ void __drm_puts_coredump(struct drm_printer *p, const char *str) > > > copy = iterator->remain; > > > > > > /* Copy out the bit of the string that we need */ > > > - memcpy(iterator->data, > > > - str + (iterator->start - iterator->offset), copy); > > > + if (iterator->data) > > > + memcpy(iterator->data, > > > + str + (iterator->start - iterator->offset), copy); > > > > > > iterator->offset = iterator->start + copy; > > > iterator->remain -= copy; > > > @@ -110,7 +111,8 @@ void __drm_puts_coredump(struct drm_printer *p, const char *str) > > > > > > len = min_t(ssize_t, strlen(str), iterator->remain); > > > > > > - memcpy(iterator->data + pos, str, len); > > > + if (iterator->data) > > > + memcpy(iterator->data + pos, str, len); > > > > > > iterator->offset += len; > > > iterator->remain -= len; > > > @@ -140,8 +142,9 @@ void __drm_printfn_coredump(struct drm_printer *p, struct va_format *vaf) > > > if ((iterator->offset >= iterator->start) && (len < iterator->remain)) { > > > ssize_t pos = iterator->offset - iterator->start; > > > > > > - snprintf(((char *) iterator->data) + pos, > > > - iterator->remain, "%pV", vaf); > > > + if (iterator->data) > > > + snprintf(((char *) iterator->data) + pos, > > > + iterator->remain, "%pV", vaf); > > > > > > iterator->offset += len; > > > iterator->remain -= len; > > > -- > > > 2.34.1 > > > > > > >
On Thu, Aug 01, 2024 at 11:05:21AM +0300, Jani Nikula wrote: > On Wed, 31 Jul 2024, Matthew Brost <matthew.brost@intel.com> wrote: > > Useful to determine size of devcoreump before writing it out. > > I find it useful to have this special case documented, with an example, > so it's easier to see how handy this really is. > Good idea, will add some kernel doc explaining the problem devcoredump in Xe and how use a devcoredump printer with NULL to make it faster. Matt > BR, > Jani. > > > > > > Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com> > > Signed-off-by: Matthew Brost <matthew.brost@intel.com> > > --- > > drivers/gpu/drm/drm_print.c | 13 ++++++++----- > > 1 file changed, 8 insertions(+), 5 deletions(-) > > > > diff --git a/drivers/gpu/drm/drm_print.c b/drivers/gpu/drm/drm_print.c > > index cf24dfdeb6b2..a1a4de9f9c44 100644 > > --- a/drivers/gpu/drm/drm_print.c > > +++ b/drivers/gpu/drm/drm_print.c > > @@ -100,8 +100,9 @@ void __drm_puts_coredump(struct drm_printer *p, const char *str) > > copy = iterator->remain; > > > > /* Copy out the bit of the string that we need */ > > - memcpy(iterator->data, > > - str + (iterator->start - iterator->offset), copy); > > + if (iterator->data) > > + memcpy(iterator->data, > > + str + (iterator->start - iterator->offset), copy); > > > > iterator->offset = iterator->start + copy; > > iterator->remain -= copy; > > @@ -110,7 +111,8 @@ void __drm_puts_coredump(struct drm_printer *p, const char *str) > > > > len = min_t(ssize_t, strlen(str), iterator->remain); > > > > - memcpy(iterator->data + pos, str, len); > > + if (iterator->data) > > + memcpy(iterator->data + pos, str, len); > > > > iterator->offset += len; > > iterator->remain -= len; > > @@ -140,8 +142,9 @@ void __drm_printfn_coredump(struct drm_printer *p, struct va_format *vaf) > > if ((iterator->offset >= iterator->start) && (len < iterator->remain)) { > > ssize_t pos = iterator->offset - iterator->start; > > > > - snprintf(((char *) iterator->data) + pos, > > - iterator->remain, "%pV", vaf); > > + if (iterator->data) > > + snprintf(((char *) iterator->data) + pos, > > + iterator->remain, "%pV", vaf); > > > > iterator->offset += len; > > iterator->remain -= len; > > -- > Jani Nikula, Intel
On Thu, Aug 01, 2024 at 08:00:21AM -0600, Cavitt, Jonathan wrote: > -----Original Message----- > From: Brost, Matthew <matthew.brost@intel.com> > Sent: Wednesday, July 31, 2024 5:03 PM > To: Cavitt, Jonathan <jonathan.cavitt@intel.com> > Cc: intel-xe@lists.freedesktop.org; dri-devel@lists.freedesktop.org; maarten.lankhorst@linux.intel.com; Vivi, Rodrigo <rodrigo.vivi@intel.com> > Subject: Re: [PATCH v4 2/3] drm/printer: Allow NULL data in devcoredump printer > > > > On Wed, Jul 31, 2024 at 04:22:03PM -0600, Cavitt, Jonathan wrote: > > > -----Original Message----- > > > From: Intel-xe <intel-xe-bounces@lists.freedesktop.org> On Behalf Of Matthew Brost > > > Sent: Wednesday, July 31, 2024 2:32 PM > > > To: intel-xe@lists.freedesktop.org; dri-devel@lists.freedesktop.org > > > Cc: maarten.lankhorst@linux.intel.com; Vivi, Rodrigo <rodrigo.vivi@intel.com> > > > Subject: [PATCH v4 2/3] drm/printer: Allow NULL data in devcoredump printer > > > > > > > > Useful to determine size of devcoreump before writing it out. > > > > > > > > Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com> > > > > Signed-off-by: Matthew Brost <matthew.brost@intel.com> > > > > > > It seems this patch prevents us from copying strings into the data field if the data > > > field hasn't been initialized. I'm not certain if it could ever be uninitialized at this > > > point, but I recognize it as good practice to check just in case regardless. > > > > > > > That's not the intent. The intent to call the print functions with NULL > > data so the printer can calculate the size of buffer required to print > > out all the devcoredump data. > > So if iterator->data is NULL, you want to NOT copy into it? > -Jonathan Cavitt Yes, exactly. Run devcoredump printer with NULL data to get size, alloc data based on devcoredump printer offset, run it again with a valid data pointer to print. Matt > > > > > Matt > > > > > Reviewed-by: Jonathan Cavitt <jonathan.cavitt@intel.com> > > > -Jonathan Cavitt > > > > > > > --- > > > > drivers/gpu/drm/drm_print.c | 13 ++++++++----- > > > > 1 file changed, 8 insertions(+), 5 deletions(-) > > > > > > > > diff --git a/drivers/gpu/drm/drm_print.c b/drivers/gpu/drm/drm_print.c > > > > index cf24dfdeb6b2..a1a4de9f9c44 100644 > > > > --- a/drivers/gpu/drm/drm_print.c > > > > +++ b/drivers/gpu/drm/drm_print.c > > > > @@ -100,8 +100,9 @@ void __drm_puts_coredump(struct drm_printer *p, const char *str) > > > > copy = iterator->remain; > > > > > > > > /* Copy out the bit of the string that we need */ > > > > - memcpy(iterator->data, > > > > - str + (iterator->start - iterator->offset), copy); > > > > + if (iterator->data) > > > > + memcpy(iterator->data, > > > > + str + (iterator->start - iterator->offset), copy); > > > > > > > > iterator->offset = iterator->start + copy; > > > > iterator->remain -= copy; > > > > @@ -110,7 +111,8 @@ void __drm_puts_coredump(struct drm_printer *p, const char *str) > > > > > > > > len = min_t(ssize_t, strlen(str), iterator->remain); > > > > > > > > - memcpy(iterator->data + pos, str, len); > > > > + if (iterator->data) > > > > + memcpy(iterator->data + pos, str, len); > > > > > > > > iterator->offset += len; > > > > iterator->remain -= len; > > > > @@ -140,8 +142,9 @@ void __drm_printfn_coredump(struct drm_printer *p, struct va_format *vaf) > > > > if ((iterator->offset >= iterator->start) && (len < iterator->remain)) { > > > > ssize_t pos = iterator->offset - iterator->start; > > > > > > > > - snprintf(((char *) iterator->data) + pos, > > > > - iterator->remain, "%pV", vaf); > > > > + if (iterator->data) > > > > + snprintf(((char *) iterator->data) + pos, > > > > + iterator->remain, "%pV", vaf); > > > > > > > > iterator->offset += len; > > > > iterator->remain -= len; > > > > -- > > > > 2.34.1 > > > > > > > > > >
-----Original Message----- From: Brost, Matthew <matthew.brost@intel.com> Sent: Thursday, August 1, 2024 7:30 AM To: Cavitt, Jonathan <jonathan.cavitt@intel.com> Cc: intel-xe@lists.freedesktop.org; dri-devel@lists.freedesktop.org; maarten.lankhorst@linux.intel.com; Vivi, Rodrigo <rodrigo.vivi@intel.com> Subject: Re: [PATCH v4 2/3] drm/printer: Allow NULL data in devcoredump printer > > On Thu, Aug 01, 2024 at 08:00:21AM -0600, Cavitt, Jonathan wrote: > > -----Original Message----- > > From: Brost, Matthew <matthew.brost@intel.com> > > Sent: Wednesday, July 31, 2024 5:03 PM > > To: Cavitt, Jonathan <jonathan.cavitt@intel.com> > > Cc: intel-xe@lists.freedesktop.org; dri-devel@lists.freedesktop.org; maarten.lankhorst@linux.intel.com; Vivi, Rodrigo <rodrigo.vivi@intel.com> > > Subject: Re: [PATCH v4 2/3] drm/printer: Allow NULL data in devcoredump printer > > > > > > On Wed, Jul 31, 2024 at 04:22:03PM -0600, Cavitt, Jonathan wrote: > > > > -----Original Message----- > > > > From: Intel-xe <intel-xe-bounces@lists.freedesktop.org> On Behalf Of Matthew Brost > > > > Sent: Wednesday, July 31, 2024 2:32 PM > > > > To: intel-xe@lists.freedesktop.org; dri-devel@lists.freedesktop.org > > > > Cc: maarten.lankhorst@linux.intel.com; Vivi, Rodrigo <rodrigo.vivi@intel.com> > > > > Subject: [PATCH v4 2/3] drm/printer: Allow NULL data in devcoredump printer > > > > > > > > > > Useful to determine size of devcoreump before writing it out. > > > > > > > > > > Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com> > > > > > Signed-off-by: Matthew Brost <matthew.brost@intel.com> > > > > > > > > It seems this patch prevents us from copying strings into the data field if the data > > > > field hasn't been initialized. I'm not certain if it could ever be uninitialized at this > > > > point, but I recognize it as good practice to check just in case regardless. > > > > > > > > > > That's not the intent. The intent to call the print functions with NULL > > > data so the printer can calculate the size of buffer required to print > > > out all the devcoredump data. > > > > So if iterator->data is NULL, you want to NOT copy into it? > > -Jonathan Cavitt > > Yes, exactly. Run devcoredump printer with NULL data to get size, alloc > data based on devcoredump printer offset, run it again with a valid data > pointer to print. Okay, I think I understand. That might be good to add to the commit message, then. Something like: """ We want to determine the size of the devcoredump before writing it out. To that end, we will run the devcoredump printer with NULL data to get the size, alloc data based on the generated offset, then run the devcorecump again with a valid data pointer to print. This necessitates not writing data to the data pointer on the initial pass, when it is NULL. """ Maybe that's a bit overboard? In either case, my RB still stands, regardless of if the commit message is updated or not. -Jonathan Cavitt > > Matt > > > > > > > > > Matt > > > > > > > Reviewed-by: Jonathan Cavitt <jonathan.cavitt@intel.com> > > > > -Jonathan Cavitt > > > > > > > > > --- > > > > > drivers/gpu/drm/drm_print.c | 13 ++++++++----- > > > > > 1 file changed, 8 insertions(+), 5 deletions(-) > > > > > > > > > > diff --git a/drivers/gpu/drm/drm_print.c b/drivers/gpu/drm/drm_print.c > > > > > index cf24dfdeb6b2..a1a4de9f9c44 100644 > > > > > --- a/drivers/gpu/drm/drm_print.c > > > > > +++ b/drivers/gpu/drm/drm_print.c > > > > > @@ -100,8 +100,9 @@ void __drm_puts_coredump(struct drm_printer *p, const char *str) > > > > > copy = iterator->remain; > > > > > > > > > > /* Copy out the bit of the string that we need */ > > > > > - memcpy(iterator->data, > > > > > - str + (iterator->start - iterator->offset), copy); > > > > > + if (iterator->data) > > > > > + memcpy(iterator->data, > > > > > + str + (iterator->start - iterator->offset), copy); > > > > > > > > > > iterator->offset = iterator->start + copy; > > > > > iterator->remain -= copy; > > > > > @@ -110,7 +111,8 @@ void __drm_puts_coredump(struct drm_printer *p, const char *str) > > > > > > > > > > len = min_t(ssize_t, strlen(str), iterator->remain); > > > > > > > > > > - memcpy(iterator->data + pos, str, len); > > > > > + if (iterator->data) > > > > > + memcpy(iterator->data + pos, str, len); > > > > > > > > > > iterator->offset += len; > > > > > iterator->remain -= len; > > > > > @@ -140,8 +142,9 @@ void __drm_printfn_coredump(struct drm_printer *p, struct va_format *vaf) > > > > > if ((iterator->offset >= iterator->start) && (len < iterator->remain)) { > > > > > ssize_t pos = iterator->offset - iterator->start; > > > > > > > > > > - snprintf(((char *) iterator->data) + pos, > > > > > - iterator->remain, "%pV", vaf); > > > > > + if (iterator->data) > > > > > + snprintf(((char *) iterator->data) + pos, > > > > > + iterator->remain, "%pV", vaf); > > > > > > > > > > iterator->offset += len; > > > > > iterator->remain -= len; > > > > > -- > > > > > 2.34.1 > > > > > > > > > > > > > >
diff --git a/drivers/gpu/drm/drm_print.c b/drivers/gpu/drm/drm_print.c index cf24dfdeb6b2..a1a4de9f9c44 100644 --- a/drivers/gpu/drm/drm_print.c +++ b/drivers/gpu/drm/drm_print.c @@ -100,8 +100,9 @@ void __drm_puts_coredump(struct drm_printer *p, const char *str) copy = iterator->remain; /* Copy out the bit of the string that we need */ - memcpy(iterator->data, - str + (iterator->start - iterator->offset), copy); + if (iterator->data) + memcpy(iterator->data, + str + (iterator->start - iterator->offset), copy); iterator->offset = iterator->start + copy; iterator->remain -= copy; @@ -110,7 +111,8 @@ void __drm_puts_coredump(struct drm_printer *p, const char *str) len = min_t(ssize_t, strlen(str), iterator->remain); - memcpy(iterator->data + pos, str, len); + if (iterator->data) + memcpy(iterator->data + pos, str, len); iterator->offset += len; iterator->remain -= len; @@ -140,8 +142,9 @@ void __drm_printfn_coredump(struct drm_printer *p, struct va_format *vaf) if ((iterator->offset >= iterator->start) && (len < iterator->remain)) { ssize_t pos = iterator->offset - iterator->start; - snprintf(((char *) iterator->data) + pos, - iterator->remain, "%pV", vaf); + if (iterator->data) + snprintf(((char *) iterator->data) + pos, + iterator->remain, "%pV", vaf); iterator->offset += len; iterator->remain -= len;
Useful to determine size of devcoreump before writing it out. Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com> Signed-off-by: Matthew Brost <matthew.brost@intel.com> --- drivers/gpu/drm/drm_print.c | 13 ++++++++----- 1 file changed, 8 insertions(+), 5 deletions(-)