| Message ID | 20220128220156.4057446-1-jmeurin@google.com |
|---|---|
| State | Changes Requested |
| Headers | show |
| Series | Fix the size of the header read buffer. | expand |
Hi Jean-Marc, jmeurin@google.com wrote on Fri, 28 Jan 2022 14:01:56 -0800: > The read buffer size depends on the MTDOOPS_HEADER_SIZE. > > Tested: Changed the header size, it doesn't panic, header is still > read/written correctly. On what Linux kernel version are you? It looks like we don't share the same code base, are we? > > Signed-off-by: Jean-Marc Eurin <jmeurin@google.com> > --- > drivers/mtd/mtdoops.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/mtd/mtdoops.c b/drivers/mtd/mtdoops.c > index 227df24387df..09a26747f490 100644 > --- a/drivers/mtd/mtdoops.c > +++ b/drivers/mtd/mtdoops.c > @@ -223,7 +223,7 @@ static void find_next_position(struct mtdoops_context *cxt) > { > struct mtd_info *mtd = cxt->mtd; > int ret, page, maxpos = 0; > - u32 count[2], maxcount = 0xffffffff; > + u32 count[MTDOOPS_HEADER_SIZE/sizeof(u32)], maxcount = 0xffffffff; > size_t retlen; > > for (page = 0; page < cxt->oops_pages; page++) { Thanks, Miquèl
On Mon, Jan 31, 2022 at 2:00 AM Miquel Raynal <miquel.raynal@bootlin.com> wrote: > > Hi Jean-Marc, > > jmeurin@google.com wrote on Fri, 28 Jan 2022 14:01:56 -0800: > > > The read buffer size depends on the MTDOOPS_HEADER_SIZE. > > > > Tested: Changed the header size, it doesn't panic, header is still > > read/written correctly. > > On what Linux kernel version are you? It looks like we don't share the > same code base, are we? https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/mtd/mtdoops.c?h=v5.17-rc2 has that bug. If you try to increase the MTDOOPS_HEADER_SIZE, find_next_position() will try to do an mtd_read() of MTDOOPS_HEADER_SIZE bytes in a count buffer that is fixed to only 8 bytes. Thanks, Jean-Marc > > > > > Signed-off-by: Jean-Marc Eurin <jmeurin@google.com> > > --- > > drivers/mtd/mtdoops.c | 2 +- > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > diff --git a/drivers/mtd/mtdoops.c b/drivers/mtd/mtdoops.c > > index 227df24387df..09a26747f490 100644 > > --- a/drivers/mtd/mtdoops.c > > +++ b/drivers/mtd/mtdoops.c > > @@ -223,7 +223,7 @@ static void find_next_position(struct mtdoops_context *cxt) > > { > > struct mtd_info *mtd = cxt->mtd; > > int ret, page, maxpos = 0; > > - u32 count[2], maxcount = 0xffffffff; > > + u32 count[MTDOOPS_HEADER_SIZE/sizeof(u32)], maxcount = 0xffffffff; > > size_t retlen; > > > > for (page = 0; page < cxt->oops_pages; page++) { > > > Thanks, > Miquèl
Hi Jean-Marc, It looks like you changed the title when answering to my question, I thought this was a v2 and could not find it in patchwork. That is because the v2 does not actually exist? jmeurin@google.com wrote on Thu, 3 Feb 2022 17:53:47 -0800: > On Mon, Jan 31, 2022 at 2:00 AM Miquel Raynal <miquel.raynal@bootlin.com> wrote: > > > > Hi Jean-Marc, > > > > jmeurin@google.com wrote on Fri, 28 Jan 2022 14:01:56 -0800: > > > > > The read buffer size depends on the MTDOOPS_HEADER_SIZE. > > > > > > Tested: Changed the header size, it doesn't panic, header is still > > > read/written correctly. > > > > On what Linux kernel version are you? It looks like we don't share the > > same code base, are we? > > https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/mtd/mtdoops.c?h=v5.17-rc2 > has that bug. If you try to increase the MTDOOPS_HEADER_SIZE, > find_next_position() will try to do an mtd_read() of > MTDOOPS_HEADER_SIZE bytes in a count buffer that is fixed to only 8 > bytes. I might have checked another function then. Indeed the fix looks legit. Can you please send a v2 with: - Your two patches in the same series (formatted with git-format-patch to get the dependency/order right) - In the other commit, drop the reference pointing to (I believe) a commit hash that is local to your tree only. - Use the right prefix ("mtd: mtdoops:"). And we should be good. > > Thanks, > > Jean-Marc > > > > > > > > > Signed-off-by: Jean-Marc Eurin <jmeurin@google.com> > > > --- > > > drivers/mtd/mtdoops.c | 2 +- > > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > > > diff --git a/drivers/mtd/mtdoops.c b/drivers/mtd/mtdoops.c > > > index 227df24387df..09a26747f490 100644 > > > --- a/drivers/mtd/mtdoops.c > > > +++ b/drivers/mtd/mtdoops.c > > > @@ -223,7 +223,7 @@ static void find_next_position(struct mtdoops_context *cxt) > > > { > > > struct mtd_info *mtd = cxt->mtd; > > > int ret, page, maxpos = 0; > > > - u32 count[2], maxcount = 0xffffffff; > > > + u32 count[MTDOOPS_HEADER_SIZE/sizeof(u32)], maxcount = 0xffffffff; > > > size_t retlen; > > > > > > for (page = 0; page < cxt->oops_pages; page++) { > > > > > > Thanks, > > Miquèl Thanks, Miquèl
diff --git a/drivers/mtd/mtdoops.c b/drivers/mtd/mtdoops.c index 227df24387df..09a26747f490 100644 --- a/drivers/mtd/mtdoops.c +++ b/drivers/mtd/mtdoops.c @@ -223,7 +223,7 @@ static void find_next_position(struct mtdoops_context *cxt) { struct mtd_info *mtd = cxt->mtd; int ret, page, maxpos = 0; - u32 count[2], maxcount = 0xffffffff; + u32 count[MTDOOPS_HEADER_SIZE/sizeof(u32)], maxcount = 0xffffffff; size_t retlen; for (page = 0; page < cxt->oops_pages; page++) {
The read buffer size depends on the MTDOOPS_HEADER_SIZE. Tested: Changed the header size, it doesn't panic, header is still read/written correctly. Signed-off-by: Jean-Marc Eurin <jmeurin@google.com> --- drivers/mtd/mtdoops.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)