a single record assuming it contains a whole PTEG but now the code tries
reading the entire PTEG and "if ((n - i) < invalid)" produces negative
values which then are converted to size_t for memset() and that throws
seg fault.
This fixes the math.
While here, fix the last @i increment as well.
Fixes: 1ad9f0a464fe "target/ppc: Fix KVM-HV HPTE accessors"
Signed-off-by: Alexey Kardashevskiy <address@hidden>
---
Record #0:
(gdb) p *hdr
$13 = {
index = <ptr>,
n_valid = 0x1,
n_invalid = 0x6
}
Record #1:
(gdb) p *hdr
$18 = {
index = <ptr>,
n_valid = 0x2,
n_invalid = 0x6
}
i.e. in the second iteration of the loop right before
"if ((n - i) < invalid)":
(gdb) p n
$16 = 0x8
(gdb) p i
$17 = 0x9
and @invalid becomes -1.
---
target/ppc/kvm.c | 11 +++++++----
1 file changed, 7 insertions(+), 4 deletions(-)
diff --git a/target/ppc/kvm.c b/target/ppc/kvm.c
index 0566af7..c2dea81 100644
--- a/target/ppc/kvm.c
+++ b/target/ppc/kvm.c
@@ -2657,21 +2657,24 @@ void kvmppc_read_hptes(ppc_hash_pte64_t *hptes, hwaddr
ptex, int n)
hdr = (struct kvm_get_htab_header *)buf;
while ((i < n) && ((char *)hdr < (buf + rc))) {
- int invalid = hdr->n_invalid;
+ int invalid = hdr->n_invalid, valid = hdr->n_valid;
if (hdr->index != (ptex + i)) {
hw_error("kvmppc_read_hptes: Unexpected HPTE index %"PRIu32
" != (%"HWADDR_PRIu" + %d", hdr->index, ptex, i);
}
- memcpy(hptes + i, hdr + 1, HASH_PTE_SIZE_64 * hdr->n_valid);
- i += hdr->n_valid;
+ if (n - i < valid) {
+ valid = n - i;
+ }
+ memcpy(hptes + i, hdr + 1, HASH_PTE_SIZE_64 * valid);
+ i += valid;
if ((n - i) < invalid) {
invalid = n - i;
}
memset(hptes + i, 0, invalid * HASH_PTE_SIZE_64);
- i += hdr->n_invalid;
+ i += invalid;
hdr = (struct kvm_get_htab_header *)
((char *)(hdr + 1) + HASH_PTE_SIZE_64 * hdr->n_valid);