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target/riscv: PMP violation due to wrong size parameter

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riscv_cpu_tlb_fill() uses the `size` parameter to check PMP violation
using pmp_hart_has_privs().
However, if the size is unknown (=0), the ending address will be
`addr - 1` as it is `addr + size - 1` in `pmp_hart_has_privs()`.
This always causes a false PMP violation on the starting address of the
range, as `addr - 1` is not in the range.

In order to fix, we just assume that all bytes from addr to the end of
the page will be accessed if the size is unknown.

Signed-off-by: Dayeol Lee <dayeol@berkeley.edu>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
This commit is contained in:
Dayeol Lee 2019-10-22 21:21:29 +00:00 committed by Palmer Dabbelt
parent 3aa9004f09
commit 9667e53573
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GPG Key ID: EF4CA1502CCBAB41
1 changed files with 12 additions and 1 deletions
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13
target/riscv/pmp.c
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@ -223,6 +223,7 @@ bool pmp_hart_has_privs(CPURISCVState *env, target_ulong addr,
{
int i = 0;
int ret = -1;
int pmp_size = 0;
target_ulong s = 0;
target_ulong e = 0;
pmp_priv_t allowed_privs = 0;
@ -232,11 +233,21 @@ bool pmp_hart_has_privs(CPURISCVState *env, target_ulong addr,
return true;
}
/*
* if size is unknown (0), assume that all bytes
* from addr to the end of the page will be accessed.
*/
if (size == 0) {
pmp_size = -(addr | TARGET_PAGE_MASK);
} else {
pmp_size = size;
}
/* 1.10 draft priv spec states there is an implicit order
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 - 1);
e = pmp_is_in_range(env, i, addr + pmp_size - 1);
/* partially inside */
if ((s + e) == 1) {