On 6/3/26 15:30, Fabiano Rosas wrote:
UBSAN complains:
runtime error: addition of unsigned offset to 0x7bc06e1f5000
overflowed to 0x7bc02e1f5000
Cast the pointer to unsigned integer to perform the arithmetic and
silence the error.
Signed-off-by: Fabiano Rosas <[email protected]>
---
tcg/region.c | 11 ++++++-----
1 file changed, 6 insertions(+), 5 deletions(-)
That's irritating. Does it work to make tcg_splitwx_diff be ptrdiff_t instead?
r~
diff --git a/tcg/region.c b/tcg/region.c
index 5d4be1453b..b405fa2ecb 100644
--- a/tcg/region.c
+++ b/tcg/region.c
@@ -112,7 +112,7 @@ const void *tcg_splitwx_to_rx(void *rw)
/* Pass NULL pointers unchanged. */
if (rw) {
g_assert(in_code_gen_buffer(rw));
- rw += tcg_splitwx_diff;
+ rw = (void *)((uintptr_t)rw + tcg_splitwx_diff);
}
return rw;
}
@@ -121,7 +121,7 @@ void *tcg_splitwx_to_rw(const void *rx)
{
/* Pass NULL pointers unchanged. */
if (rx) {
- rx -= tcg_splitwx_diff;
+ rx = (void *)((uintptr_t)rx - tcg_splitwx_diff);
/* Assert that we end with a pointer in the rw region. */
g_assert(in_code_gen_buffer(rx));
}
@@ -200,7 +200,7 @@ static struct tcg_region_tree *tc_ptr_to_region_tree(const
void *p)
* a signal handler over which the caller has no control.
*/
if (!in_code_gen_buffer(p)) {
- p -= tcg_splitwx_diff;
+ p = (void *)((uintptr_t)p - tcg_splitwx_diff);
if (!in_code_gen_buffer(p)) {
return NULL;
}
@@ -763,8 +763,9 @@ void tcg_region_init(size_t tb_size, int splitwx, unsigned
max_threads)
/* Request large pages for the buffer and the splitwx. */
qemu_madvise(region.start_aligned, region.total_size, QEMU_MADV_HUGEPAGE);
if (tcg_splitwx_diff) {
- qemu_madvise(region.start_aligned + tcg_splitwx_diff,
- region.total_size, QEMU_MADV_HUGEPAGE);
+ uintptr_t buf_rx = (uintptr_t)region.start_aligned + tcg_splitwx_diff;
+
+ qemu_madvise((void *)buf_rx, region.total_size, QEMU_MADV_HUGEPAGE);
}
/*
