Message ID | 20240405143015.717429-1-arnd@kernel.org |
---|---|
State | Accepted |
Headers | show |
Series | mtd: diskonchip: work around ubsan link failure | expand |
On Fri, 2024-04-05 at 14:30:04 UTC, Arnd Bergmann wrote: > From: Arnd Bergmann <arnd@arndb.de> > > I ran into a randconfig build failure with UBSAN using gcc-13.2: > > arm-linux-gnueabi-ld: error: unplaced orphan section `.bss..Lubsan_data31' from `drivers/mtd/nand/raw/diskonchip.o' > > I'm not entirely sure what is going on here, but I suspect this has something > to do with the check for the end of the doc_locations[] array that contains > an (unsigned long)0xffffffff element, which is compared against the signed > (int)0xffffffff. If this is the case, we should get a runtime check for > undefined behavior, but we instead get an unexpected build-time error. > > I would have expected this to work fine on 32-bit architectures despite the > signed integer overflow, though on 64-bit architectures this likely won't > ever work. > > Changing the contition to instead check for the size of the array makes the > code safe everywhere and avoids the ubsan check that leads to the link > error. The loop code goes back to before 2.6.12. > > Cc: stable@vger.kernel.org > Signed-off-by: Arnd Bergmann <arnd@arndb.de> Applied to https://git.kernel.org/pub/scm/linux/kernel/git/mtd/linux.git mtd/fixes, thanks. Miquel
diff --git a/drivers/mtd/nand/raw/diskonchip.c b/drivers/mtd/nand/raw/diskonchip.c index 5243fab9face..8db7fc424571 100644 --- a/drivers/mtd/nand/raw/diskonchip.c +++ b/drivers/mtd/nand/raw/diskonchip.c @@ -53,7 +53,7 @@ static unsigned long doc_locations[] __initdata = { 0xe8000, 0xea000, 0xec000, 0xee000, #endif #endif - 0xffffffff }; +}; static struct mtd_info *doclist = NULL; @@ -1554,7 +1554,7 @@ static int __init init_nanddoc(void) if (ret < 0) return ret; } else { - for (i = 0; (doc_locations[i] != 0xffffffff); i++) { + for (i = 0; i < ARRAY_SIZE(doc_locations); i++) { doc_probe(doc_locations[i]); } }