Use only sig & 63 when checking SA_ONSTACK.

2024-08-05 16:09:36 +02:00
parent fed49a29af
commit 79e1550215
1 changed files with 5 additions and 2 deletions
@@ -240,9 +240,12 @@ asmfunction!(__relibc_internal_sigentry: ["
    // skip the sigaltstack logic.
    lea rdx, [rip + {pctl} + {pctl_off_actions}]

+    mov ecx, eax
+    and ecx, 63
+
    // LEA doesn't support 16x, so just do two x8s.
-    lea rdx, [rdx + 8 * rax]
-    lea rdx, [rdx + 8 * rax]
+    lea rdx, [rdx + 8 * rcx]
+    lea rdx, [rdx + 8 * rcx]

    bt qword ptr [rdx], {SA_ONSTACK_BIT}
    jnc 4f