From 9efd95cda50605c52a9652b5ad01e09e6fd86106 Mon Sep 17 00:00:00 2001 From: Liam Date: Tue, 28 Mar 2023 22:28:27 -0400 Subject: kernel: fix unbounded stack usage in atomics --- src/core/hle/kernel/k_condition_variable.cpp | 27 ++++++++++++++++----------- 1 file changed, 16 insertions(+), 11 deletions(-) (limited to 'src/core/hle/kernel/k_condition_variable.cpp') diff --git a/src/core/hle/kernel/k_condition_variable.cpp b/src/core/hle/kernel/k_condition_variable.cpp index 73017cf99..efbac0e6a 100644 --- a/src/core/hle/kernel/k_condition_variable.cpp +++ b/src/core/hle/kernel/k_condition_variable.cpp @@ -33,21 +33,26 @@ bool UpdateLockAtomic(Core::System& system, u32* out, KProcessAddress address, u auto& monitor = system.Monitor(); const auto current_core = system.Kernel().CurrentPhysicalCoreIndex(); - // Load the value from the address. - const auto expected = monitor.ExclusiveRead32(current_core, GetInteger(address)); + u32 expected{}; - // Orr in the new mask. - u32 value = expected | new_orr_mask; + while (true) { + // Load the value from the address. + expected = monitor.ExclusiveRead32(current_core, GetInteger(address)); - // If the value is zero, use the if_zero value, otherwise use the newly orr'd value. - if (!expected) { - value = if_zero; - } + // Orr in the new mask. + u32 value = expected | new_orr_mask; + + // If the value is zero, use the if_zero value, otherwise use the newly orr'd value. + if (!expected) { + value = if_zero; + } + + // Try to store. + if (monitor.ExclusiveWrite32(current_core, GetInteger(address), value)) { + break; + } - // Try to store. - if (!monitor.ExclusiveWrite32(current_core, GetInteger(address), value)) { // If we failed to store, try again. - return UpdateLockAtomic(system, out, address, if_zero, new_orr_mask); } // We're done. -- cgit v1.2.3