| Message ID | 20170708025030.15845-2-rth@twiddle.net (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 07/07/2017 11:50 PM, Richard Henderson wrote: > Most of the users of page_set_flags offset (page, page + len) as > the end points. One might consider this an error, since the other > users do supply an endpoint as the last byte of the region. > > However, the first thing that page_set_flags does is round end UP > to the start of the next page. Which means computing page + len - 1 > is in the end pointless. Therefore, accept this usage and do not > assert when given the exact size of the vm as the endpoint. > > Signed-off-by: Richard Henderson <rth@twiddle.net> > --- > accel/tcg/translate-all.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/accel/tcg/translate-all.c b/accel/tcg/translate-all.c > index dfb9f0d..57578a4 100644 > --- a/accel/tcg/translate-all.c > +++ b/accel/tcg/translate-all.c > @@ -2068,7 +2068,7 @@ void page_set_flags(target_ulong start, target_ulong end, int flags) > guest address space. If this assert fires, it probably indicates > a missing call to h2g_valid. */ > #if TARGET_ABI_BITS > L1_MAP_ADDR_SPACE_BITS > - assert(end < ((target_ulong)1 << L1_MAP_ADDR_SPACE_BITS)); > + assert(end <= ((target_ulong)1 << L1_MAP_ADDR_SPACE_BITS)); worth adding a comment /* end rounded up */ ? anyway for this tricky catch: Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org> > #endif > assert(start < end); > assert_memory_lock(); >
diff --git a/accel/tcg/translate-all.c b/accel/tcg/translate-all.c index dfb9f0d..57578a4 100644 --- a/accel/tcg/translate-all.c +++ b/accel/tcg/translate-all.c @@ -2068,7 +2068,7 @@ void page_set_flags(target_ulong start, target_ulong end, int flags) guest address space. If this assert fires, it probably indicates a missing call to h2g_valid. */ #if TARGET_ABI_BITS > L1_MAP_ADDR_SPACE_BITS - assert(end < ((target_ulong)1 << L1_MAP_ADDR_SPACE_BITS)); + assert(end <= ((target_ulong)1 << L1_MAP_ADDR_SPACE_BITS)); #endif assert(start < end); assert_memory_lock();
Most of the users of page_set_flags offset (page, page + len) as the end points. One might consider this an error, since the other users do supply an endpoint as the last byte of the region. However, the first thing that page_set_flags does is round end UP to the start of the next page. Which means computing page + len - 1 is in the end pointless. Therefore, accept this usage and do not assert when given the exact size of the vm as the endpoint. Signed-off-by: Richard Henderson <rth@twiddle.net> --- accel/tcg/translate-all.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)