[Qemu-devel] [PATCH v1 1/4] target/riscv: Fix PMP range boundary address bug

[Alistair Francis <alistair.francis@wdc.com>]

From: Dayeol Lee <dayeol@berkeley.edu>

A wrong address is passed to `pmp_is_in_range` while checking if a
memory access is within a PMP range.
Since the ending address of the pmp range (i.e., pmp_state.addr[i].ea)
is set to the last address in the range (i.e., pmp base + pmp size - 1),
memory accesses containg the last address in the range will always fail.

For example, assume that a PMP range is 4KB from 0x87654000 such that
the last address within the range is 0x87654fff.
1-byte access to 0x87654fff should be considered to be fully inside the
PMP range.
However the access now fails and complains partial inclusion because
pmp_is_in_range(env, i, addr + size) returns 0 whereas
pmp_is_in_range(env, i, addr) returns 1.

Signed-off-by: Dayeol Lee <dayeol@berkeley.edu>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Michael Clark <mjc@sifive.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
---
 target/riscv/pmp.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/target/riscv/pmp.c b/target/riscv/pmp.c
index b11c4ae22f..a2fcc90d73 100644
--- a/target/riscv/pmp.c
+++ b/target/riscv/pmp.c
@@ -246,7 +246,7 @@ bool pmp_hart_has_privs(CPURISCVState *env, target_ulong addr,
          from low to high */
     for (i = 0; i < MAX_RISCV_PMPS; i++) {
         s = pmp_is_in_range(env, i, addr);
-        e = pmp_is_in_range(env, i, addr + size);
+        e = pmp_is_in_range(env, i, addr + size - 1);
 
         /* partially inside */
         if ((s + e) == 1) {
-- 
2.21.0