* OLPC regression, ofdisk stops working [not found] <E1LwZ2d-0006vu-Be@cvs.savannah.gnu.org> @ 2009-07-09 16:03 ` Robert Millan 2009-07-10 14:28 ` Bean 0 siblings, 1 reply; 6+ messages in thread From: Robert Millan @ 2009-07-09 16:03 UTC (permalink / raw) To: grub-devel; +Cc: David S. Miller Hi, I got completely puzzled at this one. Turns out r2132 broke ofdisk on OLPC. But I don't see anything wrong in this commit. I isolated the change that causes this breakage, and it's very confusing. It turns out that allocating devtype in the heap instead of the stack causes its result to be truncated to 4 bytes (+ null terminator). I'm not sure what can we do about this. If we're certain it's an OFW bug, perhaps we could workaround it by comparing only the first 4 bytes of the result. This worked for me: - if (! grub_strcmp (alias->type, "block")) + if (! grub_strncmp (alias->type, "bloc", 4)) (but using the existing "workaround framework") but it's scary. I don't know if this 4-byte limit is consistent, or will differ arbitrarily. Maybe we could issue a warning or so, I don't know. Is there someone else (Bean?) who can reproduce this problem? Does it fail in the same way? On Wed, Apr 22, 2009 at 09:46:55AM +0000, David S. Miller wrote: > Revision: 2132 > http://svn.sv.gnu.org/viewvc/?view=rev&root=grub&revision=2132 > Author: davem > Date: 2009-04-22 09:46:54 +0000 (Wed, 22 Apr 2009) > Log Message: > ----------- > * include/grub/ieee1275/ieee1275.h (IEEE1275_MAX_PROP_LEN, > IEEE1275_MAX_PATH_LEN): Define. > * kern/ieee1275/openfw.c (grub_children_iterate): Dynamically > allocate 'childtype', 'childpath', 'childname', and 'fullname'. > (grub_devalias_iterate): Dynamically allocate 'aliasname' and > 'devtype'. Explicitly NULL terminate devalias expansion. > > Modified Paths: > -------------- > trunk/grub2/ChangeLog > trunk/grub2/include/grub/ieee1275/ieee1275.h > trunk/grub2/kern/ieee1275/openfw.c > > Modified: trunk/grub2/ChangeLog > =================================================================== > --- trunk/grub2/ChangeLog 2009-04-22 09:45:43 UTC (rev 2131) > +++ trunk/grub2/ChangeLog 2009-04-22 09:46:54 UTC (rev 2132) > @@ -3,6 +3,13 @@ > * kern/ieee1275/mmap.c (grub_machine_mmap_iterate): If size_cells > is larger than address_cells, use that value for address_cells too. > > + * include/grub/ieee1275/ieee1275.h (IEEE1275_MAX_PROP_LEN, > + IEEE1275_MAX_PATH_LEN): Define. > + * kern/ieee1275/openfw.c (grub_children_iterate): Dynamically > + allocate 'childtype', 'childpath', 'childname', and 'fullname'. > + (grub_devalias_iterate): Dynamically allocate 'aliasname' and > + 'devtype'. Explicitly NULL terminate devalias expansion. > + > 2009-04-19 Vladimir Serbinenko <phcoder@gmail.com> > > Correct GPT definition > > Modified: trunk/grub2/include/grub/ieee1275/ieee1275.h > =================================================================== > --- trunk/grub2/include/grub/ieee1275/ieee1275.h 2009-04-22 09:45:43 UTC (rev 2131) > +++ trunk/grub2/include/grub/ieee1275/ieee1275.h 2009-04-22 09:46:54 UTC (rev 2132) > @@ -39,6 +39,9 @@ > unsigned int size; > }; > > +#define IEEE1275_MAX_PROP_LEN 8192 > +#define IEEE1275_MAX_PATH_LEN 256 > + > #ifndef IEEE1275_CALL_ENTRY_FN > #define IEEE1275_CALL_ENTRY_FN(args) (*grub_ieee1275_entry_fn) (args) > #endif > > Modified: trunk/grub2/kern/ieee1275/openfw.c > =================================================================== > --- trunk/grub2/kern/ieee1275/openfw.c 2009-04-22 09:45:43 UTC (rev 2131) > +++ trunk/grub2/kern/ieee1275/openfw.c 2009-04-22 09:46:54 UTC (rev 2132) > @@ -38,6 +38,8 @@ > { > grub_ieee1275_phandle_t dev; > grub_ieee1275_phandle_t child; > + char *childtype, *childpath; > + char *childname, *fullname; > > if (grub_ieee1275_finddevice (devpath, &dev)) > return grub_error (GRUB_ERR_UNKNOWN_DEVICE, "Unknown device"); > @@ -45,13 +47,33 @@ > if (grub_ieee1275_child (dev, &child)) > return grub_error (GRUB_ERR_BAD_DEVICE, "Device has no children"); > > + childtype = grub_malloc (IEEE1275_MAX_PROP_LEN); > + if (!childtype) > + return grub_errno; > + childpath = grub_malloc (IEEE1275_MAX_PATH_LEN); > + if (!childpath) > + { > + grub_free (childtype); > + return grub_errno; > + } > + childname = grub_malloc (IEEE1275_MAX_PROP_LEN); > + if (!childname) > + { > + grub_free (childpath); > + grub_free (childtype); > + return grub_errno; > + } > + fullname = grub_malloc (IEEE1275_MAX_PATH_LEN); > + if (!fullname) > + { > + grub_free (childname); > + grub_free (childpath); > + grub_free (childtype); > + return grub_errno; > + } > + > do > { > - /* XXX: Don't use hardcoded path lengths. */ > - char childtype[64]; > - char childpath[64]; > - char childname[64]; > - char fullname[64]; > struct grub_ieee1275_devalias alias; > grub_ssize_t actual; > > @@ -76,6 +98,11 @@ > } > while (grub_ieee1275_peer (child, &child)); > > + grub_free (fullname); > + grub_free (childname); > + grub_free (childpath); > + grub_free (childtype); > + > return 0; > } > > @@ -85,13 +112,23 @@ > grub_devalias_iterate (int (*hook) (struct grub_ieee1275_devalias *alias)) > { > grub_ieee1275_phandle_t aliases; > - char aliasname[32]; > + char *aliasname, *devtype; > grub_ssize_t actual; > struct grub_ieee1275_devalias alias; > > if (grub_ieee1275_finddevice ("/aliases", &aliases)) > return -1; > > + aliasname = grub_malloc (IEEE1275_MAX_PROP_LEN); > + if (!aliasname) > + return grub_errno; > + devtype = grub_malloc (IEEE1275_MAX_PROP_LEN); > + if (!devtype) > + { > + grub_free (aliasname); > + return grub_errno; > + } > + > /* Find the first property. */ > aliasname[0] = '\0'; > > @@ -100,8 +137,6 @@ > grub_ieee1275_phandle_t dev; > grub_ssize_t pathlen; > char *devpath; > - /* XXX: This should be large enough for any possible case. */ > - char devtype[64]; > > grub_dprintf ("devalias", "devalias name = %s\n", aliasname); > > @@ -111,9 +146,17 @@ > if (!grub_strcmp (aliasname, "name")) > continue; > > + /* Sun's OpenBoot often doesn't zero terminate the device alias > + strings, so we will add a NULL byte at the end explicitly. */ > + pathlen += 1; > + > devpath = grub_malloc (pathlen); > if (! devpath) > - return grub_errno; > + { > + grub_free (devtype); > + grub_free (aliasname); > + return grub_errno; > + } > > if (grub_ieee1275_get_property (aliases, aliasname, devpath, pathlen, > &actual)) > @@ -121,6 +164,7 @@ > grub_dprintf ("devalias", "get_property (%s) failed\n", aliasname); > goto nextprop; > } > + devpath [actual] = '\0'; > > if (grub_ieee1275_finddevice (devpath, &dev)) > { > @@ -144,6 +188,8 @@ > grub_free (devpath); > } > > + grub_free (devtype); > + grub_free (aliasname); > return 0; > } > > > > > -- Robert Millan The DRM opt-in fallacy: "Your data belongs to us. We will decide when (and how) you may access your data; but nobody's threatening your freedom: we still allow you to remove your data and not access it at all." ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: OLPC regression, ofdisk stops working 2009-07-09 16:03 ` OLPC regression, ofdisk stops working Robert Millan @ 2009-07-10 14:28 ` Bean 2009-07-10 17:41 ` Robert Millan 0 siblings, 1 reply; 6+ messages in thread From: Bean @ 2009-07-10 14:28 UTC (permalink / raw) To: The development of GRUB 2 Hi, There is something wrong with r2132, now childtype is a pointer, so sizeof childtype == 4, the name would be truncated to 4 characters. diff --git a/kern/ieee1275/openfw.c b/kern/ieee1275/openfw.c index e7979f4..42d9278 100644 --- a/kern/ieee1275/openfw.c +++ b/kern/ieee1275/openfw.c @@ -78,15 +78,15 @@ grub_children_iterate (char *devpath, grub_ssize_t actual; if (grub_ieee1275_get_property (child, "device_type", childtype, - sizeof childtype, &actual)) + IEEE1275_MAX_PROP_LEN, &actual)) continue; - if (grub_ieee1275_package_to_path (child, childpath, sizeof childpath, - &actual)) + if (grub_ieee1275_package_to_path (child, childpath, + IEEE1275_MAX_PATH_LEN, &actual)) continue; if (grub_ieee1275_get_property (child, "name", childname, - sizeof childname, &actual)) + IEEE1275_MAX_PATH_LEN, &actual)) continue; grub_sprintf (fullname, "%s/%s", devpath, childname); On Fri, Jul 10, 2009 at 12:03 AM, Robert Millan<rmh@aybabtu.com> wrote: > > Hi, > > I got completely puzzled at this one. Turns out r2132 broke ofdisk on > OLPC. But I don't see anything wrong in this commit. > > I isolated the change that causes this breakage, and it's very confusing. > It turns out that allocating devtype in the heap instead of the stack > causes its result to be truncated to 4 bytes (+ null terminator). > > I'm not sure what can we do about this. If we're certain it's an OFW > bug, perhaps we could workaround it by comparing only the first 4 bytes > of the result. This worked for me: > > - if (! grub_strcmp (alias->type, "block")) > + if (! grub_strncmp (alias->type, "bloc", 4)) > > (but using the existing "workaround framework") > > but it's scary. I don't know if this 4-byte limit is consistent, or > will differ arbitrarily. Maybe we could issue a warning or so, I don't > know. > > Is there someone else (Bean?) who can reproduce this problem? Does it > fail in the same way? > > On Wed, Apr 22, 2009 at 09:46:55AM +0000, David S. Miller wrote: >> Revision: 2132 >> http://svn.sv.gnu.org/viewvc/?view=rev&root=grub&revision=2132 >> Author: davem >> Date: 2009-04-22 09:46:54 +0000 (Wed, 22 Apr 2009) >> Log Message: >> ----------- >> * include/grub/ieee1275/ieee1275.h (IEEE1275_MAX_PROP_LEN, >> IEEE1275_MAX_PATH_LEN): Define. >> * kern/ieee1275/openfw.c (grub_children_iterate): Dynamically >> allocate 'childtype', 'childpath', 'childname', and 'fullname'. >> (grub_devalias_iterate): Dynamically allocate 'aliasname' and >> 'devtype'. Explicitly NULL terminate devalias expansion. >> >> Modified Paths: >> -------------- >> trunk/grub2/ChangeLog >> trunk/grub2/include/grub/ieee1275/ieee1275.h >> trunk/grub2/kern/ieee1275/openfw.c >> >> Modified: trunk/grub2/ChangeLog >> =================================================================== >> --- trunk/grub2/ChangeLog 2009-04-22 09:45:43 UTC (rev 2131) >> +++ trunk/grub2/ChangeLog 2009-04-22 09:46:54 UTC (rev 2132) >> @@ -3,6 +3,13 @@ >> * kern/ieee1275/mmap.c (grub_machine_mmap_iterate): If size_cells >> is larger than address_cells, use that value for address_cells too. >> >> + * include/grub/ieee1275/ieee1275.h (IEEE1275_MAX_PROP_LEN, >> + IEEE1275_MAX_PATH_LEN): Define. >> + * kern/ieee1275/openfw.c (grub_children_iterate): Dynamically >> + allocate 'childtype', 'childpath', 'childname', and 'fullname'. >> + (grub_devalias_iterate): Dynamically allocate 'aliasname' and >> + 'devtype'. Explicitly NULL terminate devalias expansion. >> + >> 2009-04-19 Vladimir Serbinenko <phcoder@gmail.com> >> >> Correct GPT definition >> >> Modified: trunk/grub2/include/grub/ieee1275/ieee1275.h >> =================================================================== >> --- trunk/grub2/include/grub/ieee1275/ieee1275.h 2009-04-22 09:45:43 UTC (rev 2131) >> +++ trunk/grub2/include/grub/ieee1275/ieee1275.h 2009-04-22 09:46:54 UTC (rev 2132) >> @@ -39,6 +39,9 @@ >> unsigned int size; >> }; >> >> +#define IEEE1275_MAX_PROP_LEN 8192 >> +#define IEEE1275_MAX_PATH_LEN 256 >> + >> #ifndef IEEE1275_CALL_ENTRY_FN >> #define IEEE1275_CALL_ENTRY_FN(args) (*grub_ieee1275_entry_fn) (args) >> #endif >> >> Modified: trunk/grub2/kern/ieee1275/openfw.c >> =================================================================== >> --- trunk/grub2/kern/ieee1275/openfw.c 2009-04-22 09:45:43 UTC (rev 2131) >> +++ trunk/grub2/kern/ieee1275/openfw.c 2009-04-22 09:46:54 UTC (rev 2132) >> @@ -38,6 +38,8 @@ >> { >> grub_ieee1275_phandle_t dev; >> grub_ieee1275_phandle_t child; >> + char *childtype, *childpath; >> + char *childname, *fullname; >> >> if (grub_ieee1275_finddevice (devpath, &dev)) >> return grub_error (GRUB_ERR_UNKNOWN_DEVICE, "Unknown device"); >> @@ -45,13 +47,33 @@ >> if (grub_ieee1275_child (dev, &child)) >> return grub_error (GRUB_ERR_BAD_DEVICE, "Device has no children"); >> >> + childtype = grub_malloc (IEEE1275_MAX_PROP_LEN); >> + if (!childtype) >> + return grub_errno; >> + childpath = grub_malloc (IEEE1275_MAX_PATH_LEN); >> + if (!childpath) >> + { >> + grub_free (childtype); >> + return grub_errno; >> + } >> + childname = grub_malloc (IEEE1275_MAX_PROP_LEN); >> + if (!childname) >> + { >> + grub_free (childpath); >> + grub_free (childtype); >> + return grub_errno; >> + } >> + fullname = grub_malloc (IEEE1275_MAX_PATH_LEN); >> + if (!fullname) >> + { >> + grub_free (childname); >> + grub_free (childpath); >> + grub_free (childtype); >> + return grub_errno; >> + } >> + >> do >> { >> - /* XXX: Don't use hardcoded path lengths. */ >> - char childtype[64]; >> - char childpath[64]; >> - char childname[64]; >> - char fullname[64]; >> struct grub_ieee1275_devalias alias; >> grub_ssize_t actual; >> >> @@ -76,6 +98,11 @@ >> } >> while (grub_ieee1275_peer (child, &child)); >> >> + grub_free (fullname); >> + grub_free (childname); >> + grub_free (childpath); >> + grub_free (childtype); >> + >> return 0; >> } >> >> @@ -85,13 +112,23 @@ >> grub_devalias_iterate (int (*hook) (struct grub_ieee1275_devalias *alias)) >> { >> grub_ieee1275_phandle_t aliases; >> - char aliasname[32]; >> + char *aliasname, *devtype; >> grub_ssize_t actual; >> struct grub_ieee1275_devalias alias; >> >> if (grub_ieee1275_finddevice ("/aliases", &aliases)) >> return -1; >> >> + aliasname = grub_malloc (IEEE1275_MAX_PROP_LEN); >> + if (!aliasname) >> + return grub_errno; >> + devtype = grub_malloc (IEEE1275_MAX_PROP_LEN); >> + if (!devtype) >> + { >> + grub_free (aliasname); >> + return grub_errno; >> + } >> + >> /* Find the first property. */ >> aliasname[0] = '\0'; >> >> @@ -100,8 +137,6 @@ >> grub_ieee1275_phandle_t dev; >> grub_ssize_t pathlen; >> char *devpath; >> - /* XXX: This should be large enough for any possible case. */ >> - char devtype[64]; >> >> grub_dprintf ("devalias", "devalias name = %s\n", aliasname); >> >> @@ -111,9 +146,17 @@ >> if (!grub_strcmp (aliasname, "name")) >> continue; >> >> + /* Sun's OpenBoot often doesn't zero terminate the device alias >> + strings, so we will add a NULL byte at the end explicitly. */ >> + pathlen += 1; >> + >> devpath = grub_malloc (pathlen); >> if (! devpath) >> - return grub_errno; >> + { >> + grub_free (devtype); >> + grub_free (aliasname); >> + return grub_errno; >> + } >> >> if (grub_ieee1275_get_property (aliases, aliasname, devpath, pathlen, >> &actual)) >> @@ -121,6 +164,7 @@ >> grub_dprintf ("devalias", "get_property (%s) failed\n", aliasname); >> goto nextprop; >> } >> + devpath [actual] = '\0'; >> >> if (grub_ieee1275_finddevice (devpath, &dev)) >> { >> @@ -144,6 +188,8 @@ >> grub_free (devpath); >> } >> >> + grub_free (devtype); >> + grub_free (aliasname); >> return 0; >> } >> >> >> >> >> > > -- > Robert Millan > > The DRM opt-in fallacy: "Your data belongs to us. We will decide when (and > how) you may access your data; but nobody's threatening your freedom: we > still allow you to remove your data and not access it at all." > > > _______________________________________________ > Grub-devel mailing list > Grub-devel@gnu.org > http://lists.gnu.org/mailman/listinfo/grub-devel > -- Bean ^ permalink raw reply related [flat|nested] 6+ messages in thread
* Re: OLPC regression, ofdisk stops working 2009-07-10 14:28 ` Bean @ 2009-07-10 17:41 ` Robert Millan 2009-07-10 18:18 ` David Miller 0 siblings, 1 reply; 6+ messages in thread From: Robert Millan @ 2009-07-10 17:41 UTC (permalink / raw) To: The development of GRUB 2 On Fri, Jul 10, 2009 at 10:28:03PM +0800, Bean wrote: > Hi, > > There is something wrong with r2132, now childtype is a pointer, so > sizeof childtype == 4, the name would be truncated to 4 characters. Bean, you never cease to amaze me. I admit the "interesting, exactly the word size" idea crossed my head, but I didn't reach any conclussion out of it :-) Nice catch. Will you commit this, or want me to? > diff --git a/kern/ieee1275/openfw.c b/kern/ieee1275/openfw.c > index e7979f4..42d9278 100644 > --- a/kern/ieee1275/openfw.c > +++ b/kern/ieee1275/openfw.c > @@ -78,15 +78,15 @@ grub_children_iterate (char *devpath, > grub_ssize_t actual; > > if (grub_ieee1275_get_property (child, "device_type", childtype, > - sizeof childtype, &actual)) > + IEEE1275_MAX_PROP_LEN, &actual)) > continue; > > - if (grub_ieee1275_package_to_path (child, childpath, sizeof childpath, > - &actual)) > + if (grub_ieee1275_package_to_path (child, childpath, > + IEEE1275_MAX_PATH_LEN, &actual)) > continue; > > if (grub_ieee1275_get_property (child, "name", childname, > - sizeof childname, &actual)) > + IEEE1275_MAX_PATH_LEN, &actual)) > continue; > > grub_sprintf (fullname, "%s/%s", devpath, childname); -- Robert Millan The DRM opt-in fallacy: "Your data belongs to us. We will decide when (and how) you may access your data; but nobody's threatening your freedom: we still allow you to remove your data and not access it at all." ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: OLPC regression, ofdisk stops working 2009-07-10 17:41 ` Robert Millan @ 2009-07-10 18:18 ` David Miller 2009-07-10 20:20 ` Robert Millan 0 siblings, 1 reply; 6+ messages in thread From: David Miller @ 2009-07-10 18:18 UTC (permalink / raw) To: grub-devel, rmh From: Robert Millan <rmh@aybabtu.com> Date: Fri, 10 Jul 2009 19:41:15 +0200 > On Fri, Jul 10, 2009 at 10:28:03PM +0800, Bean wrote: >> Hi, >> >> There is something wrong with r2132, now childtype is a pointer, so >> sizeof childtype == 4, the name would be truncated to 4 characters. > > Bean, you never cease to amaze me. I admit the "interesting, exactly > the word size" idea crossed my head, but I didn't reach any conclussion > out of it :-) > > Nice catch. Will you commit this, or want me to? Good catch, I thought I had gotten all of those size conversions correct, guess not :-/ ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: OLPC regression, ofdisk stops working 2009-07-10 18:18 ` David Miller @ 2009-07-10 20:20 ` Robert Millan 2009-07-11 3:59 ` Bean 0 siblings, 1 reply; 6+ messages in thread From: Robert Millan @ 2009-07-10 20:20 UTC (permalink / raw) To: The development of GRUB 2 On Fri, Jul 10, 2009 at 11:18:28AM -0700, David Miller wrote: > From: Robert Millan <rmh@aybabtu.com> > Date: Fri, 10 Jul 2009 19:41:15 +0200 > > > On Fri, Jul 10, 2009 at 10:28:03PM +0800, Bean wrote: > >> Hi, > >> > >> There is something wrong with r2132, now childtype is a pointer, so > >> sizeof childtype == 4, the name would be truncated to 4 characters. > > > > Bean, you never cease to amaze me. I admit the "interesting, exactly > > the word size" idea crossed my head, but I didn't reach any conclussion > > out of it :-) > > > > Nice catch. Will you commit this, or want me to? > > Good catch, I thought I had gotten all of those size > conversions correct, guess not :-/ Don't worry about it, shit happens. Btw, I just committed it. I found another instance of the same problem in that file, which I fixed as well. Thanks a lot Bean! -- Robert Millan The DRM opt-in fallacy: "Your data belongs to us. We will decide when (and how) you may access your data; but nobody's threatening your freedom: we still allow you to remove your data and not access it at all." ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: OLPC regression, ofdisk stops working 2009-07-10 20:20 ` Robert Millan @ 2009-07-11 3:59 ` Bean 0 siblings, 0 replies; 6+ messages in thread From: Bean @ 2009-07-11 3:59 UTC (permalink / raw) To: The development of GRUB 2 On Sat, Jul 11, 2009 at 4:20 AM, Robert Millan<rmh@aybabtu.com> wrote: > On Fri, Jul 10, 2009 at 11:18:28AM -0700, David Miller wrote: >> From: Robert Millan <rmh@aybabtu.com> >> Date: Fri, 10 Jul 2009 19:41:15 +0200 >> >> > On Fri, Jul 10, 2009 at 10:28:03PM +0800, Bean wrote: >> >> Hi, >> >> >> >> There is something wrong with r2132, now childtype is a pointer, so >> >> sizeof childtype == 4, the name would be truncated to 4 characters. >> > >> > Bean, you never cease to amaze me. I admit the "interesting, exactly >> > the word size" idea crossed my head, but I didn't reach any conclussion >> > out of it :-) >> > >> > Nice catch. Will you commit this, or want me to? >> >> Good catch, I thought I had gotten all of those size >> conversions correct, guess not :-/ > > Don't worry about it, shit happens. > > Btw, I just committed it. I found another instance of the same problem in > that file, which I fixed as well. Hi, Oh nice. BTW, I just notice a small error in my previous patch, the size of childname is IEEE1275_MAX_PROP_LEN instead of IEEE1275_MAX_PATH_LEN, I've committed the fix now. -- Bean ^ permalink raw reply [flat|nested] 6+ messages in thread
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2009-07-09 16:03 ` OLPC regression, ofdisk stops working Robert Millan
2009-07-10 14:28 ` Bean
2009-07-10 17:41 ` Robert Millan
2009-07-10 18:18 ` David Miller
2009-07-10 20:20 ` Robert Millan
2009-07-11 3:59 ` Bean
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