On 13/8/24 10:00, Andrew Jones wrote:
On Tue, Aug 13, 2024 at 05:43:07PM GMT, Richard Henderson wrote:
On 8/13/24 17:13, Andrew Jones wrote:
C doesn't extend the sign bit for unsigned types since there isn't a
sign bit to extend. This means a promotion of a u32 to a u64 results
in the upper 32 bits of the u64 being zero. If that result is then
used as a mask on another u64 the upper 32 bits will be cleared. rv32
physical addresses may be up to 34 bits wide, so we don't want to
clear the high bits while page aligning the address. The fix is to
revert to using target_long, since a signed type will get extended.
Fixes: af3fc195e3c8 ("target/riscv: Change the TLB page size depends on PMP
entries.")
Signed-off-by: Andrew Jones <ajo...@ventanamicro.com>
---
target/riscv/cpu_helper.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/target/riscv/cpu_helper.c b/target/riscv/cpu_helper.c
index 395a1d914061..dfef1b20d1e8 100644
--- a/target/riscv/cpu_helper.c
+++ b/target/riscv/cpu_helper.c
@@ -1323,7 +1323,7 @@ bool riscv_cpu_tlb_fill(CPUState *cs, vaddr address, int
size,
int ret = TRANSLATE_FAIL;
int mode = mmuidx_priv(mmu_idx);
/* default TLB page size */
- target_ulong tlb_size = TARGET_PAGE_SIZE;
+ target_long tlb_size = TARGET_PAGE_SIZE;
If rv32 physical addresses are 34 bits, then you probably didn't want
target_*long at all.
Yes, just using hwaddr for everything that only touches physical addresses
would probably be best, but, ifaict, it's pretty common to use target_long
for masks used on both virtual and physical addresses (TARGET_PAGE_MASK,
for example). This 'tlb_size' variable is used on both as well.
Then maybe you want vaddr ("exec/vaddr.h"):
/**
* vaddr:
* Type wide enough to contain any #target_ulong virtual address.
*/
