| Message ID | 20161001141931.32354-21-paul.burton@imgtec.com |
|---|---|
| State | Deferred |
| Delegated to: | Tom Rini |
| Headers | show |
Hi Paul, On 1 October 2016 at 08:19, Paul Burton <paul.burton@imgtec.com> wrote: > When determining the region of memory to allow for use by bootm, using > bi_memstart & adding bi_memsize can cause problems if that leads to an > integer overflow. For example on some MIPS systems bi_memstart would be > 0xffffffff80000000 (ie. the start of the MIPS ckseg0 region) and if the > system has 2GB of memory then the addition would wrap around to 0. What will wrap around to 0? Isn't gd->bd->bi_memsize equal to 2GB, and gd->ram_top - start the same? > > The maximum amount of memory to be used by U-Boot is already accounted > for by the ram_top field of struct global_data, so make use of that for > the calculation instead. > > Signed-off-by: Paul Burton <paul.burton@imgtec.com> > --- > > common/image.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/common/image.c b/common/image.c > index 1581022..25e632b 100644 > --- a/common/image.c > +++ b/common/image.c > @@ -489,7 +489,7 @@ phys_size_t getenv_bootm_size(void) > size = gd->bd->bi_dram[0].size; > #else > start = (ulong)phys_to_virt(gd->bd->bi_memstart); > - size = gd->bd->bi_memsize; > + size = gd->ram_top - start; > #endif > > s = getenv("bootm_low"); > -- > 2.10.0 > Regards, Simon
diff --git a/common/image.c b/common/image.c index 1581022..25e632b 100644 --- a/common/image.c +++ b/common/image.c @@ -489,7 +489,7 @@ phys_size_t getenv_bootm_size(void) size = gd->bd->bi_dram[0].size; #else start = (ulong)phys_to_virt(gd->bd->bi_memstart); - size = gd->bd->bi_memsize; + size = gd->ram_top - start; #endif s = getenv("bootm_low");
When determining the region of memory to allow for use by bootm, using bi_memstart & adding bi_memsize can cause problems if that leads to an integer overflow. For example on some MIPS systems bi_memstart would be 0xffffffff80000000 (ie. the start of the MIPS ckseg0 region) and if the system has 2GB of memory then the addition would wrap around to 0. The maximum amount of memory to be used by U-Boot is already accounted for by the ram_top field of struct global_data, so make use of that for the calculation instead. Signed-off-by: Paul Burton <paul.burton@imgtec.com> --- common/image.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)