From: Richard Henderson <[email protected]> The token is not computed via TARGET_PAGE_SIZE, but via a fixed 12-bit field.
Cc: [email protected] Fixes: ad1afe433fa ("linux-user/aarch64: Implement map_shadow_stack syscall") Resolves: https://gitlab.com/qemu-project/qemu/-/work_items/4106 Signed-off-by: Richard Henderson <[email protected]> Reviewed-by: Pierrick Bouvier <[email protected]> Signed-off-by: Helge Deller <[email protected]> (cherry picked from commit 8d0ac5933aa3476283c14680f165727268103fcd) Signed-off-by: Michael Tokarev <[email protected]> diff --git a/linux-user/syscall.c b/linux-user/syscall.c index dcf461806ad..85ef8261e63 100644 --- a/linux-user/syscall.c +++ b/linux-user/syscall.c @@ -6848,7 +6848,8 @@ static abi_long do_map_shadow_stack(CPUArchState *env, abi_ulong addr, /* Leave an extra empty frame at top-of-stack. */ cap_ptr -= 8; } - cap_val = (cap_ptr & TARGET_PAGE_MASK) | 1; + /* Note the 12 bit field is unaffected by current page size. */ + cap_val = deposit64(cap_ptr, 0, 12, 1); if (put_user_u64(cap_val, cap_ptr)) { /* Allocation succeeded above. */ g_assert_not_reached(); -- 2.47.3
