| Kconfig (e0b8fcfa3cfac171d589ad6085a00c584d571f08) | Kconfig (5fa31af31e726c7f5a8f84800153054ca499338a) |
|---|---|
| 1# SPDX-License-Identifier: GPL-2.0 2# Select 32 or 64 bit 3config 64BIT 4 bool "64-bit kernel" if "$(ARCH)" = "x86" 5 default "$(ARCH)" != "i386" 6 help 7 Say yes to build a 64-bit kernel - formerly known as x86_64 8 Say no to build a 32-bit kernel - formerly known as i386 --- 2509 unchanged lines hidden (view full) --- 2518 2519config CPU_UNRET_ENTRY 2520 bool "Enable UNRET on kernel entry" 2521 depends on CPU_SUP_AMD && RETHUNK && X86_64 2522 default y 2523 help 2524 Compile the kernel with support for the retbleed=unret mitigation. 2525 | 1# SPDX-License-Identifier: GPL-2.0 2# Select 32 or 64 bit 3config 64BIT 4 bool "64-bit kernel" if "$(ARCH)" = "x86" 5 default "$(ARCH)" != "i386" 6 help 7 Say yes to build a 64-bit kernel - formerly known as x86_64 8 Say no to build a 32-bit kernel - formerly known as i386 --- 2509 unchanged lines hidden (view full) --- 2518 2519config CPU_UNRET_ENTRY 2520 bool "Enable UNRET on kernel entry" 2521 depends on CPU_SUP_AMD && RETHUNK && X86_64 2522 default y 2523 help 2524 Compile the kernel with support for the retbleed=unret mitigation. 2525 |
| 2526config CALL_DEPTH_TRACKING | 2526config MITIGATION_CALL_DEPTH_TRACKING |
| 2527 bool "Mitigate RSB underflow with call depth tracking" 2528 depends on CPU_SUP_INTEL && HAVE_CALL_THUNKS 2529 select HAVE_DYNAMIC_FTRACE_NO_PATCHABLE 2530 select CALL_THUNKS 2531 default y 2532 help 2533 Compile the kernel with call depth tracking to mitigate the Intel 2534 SKL Return-Speculation-Buffer (RSB) underflow issue. The 2535 mitigation is off by default and needs to be enabled on the 2536 kernel command line via the retbleed=stuff option. For 2537 non-affected systems the overhead of this option is marginal as 2538 the call depth tracking is using run-time generated call thunks 2539 in a compiler generated padding area and call patching. This 2540 increases text size by ~5%. For non affected systems this space 2541 is unused. On affected SKL systems this results in a significant 2542 performance gain over the IBRS mitigation. 2543 2544config CALL_THUNKS_DEBUG 2545 bool "Enable call thunks and call depth tracking debugging" | 2527 bool "Mitigate RSB underflow with call depth tracking" 2528 depends on CPU_SUP_INTEL && HAVE_CALL_THUNKS 2529 select HAVE_DYNAMIC_FTRACE_NO_PATCHABLE 2530 select CALL_THUNKS 2531 default y 2532 help 2533 Compile the kernel with call depth tracking to mitigate the Intel 2534 SKL Return-Speculation-Buffer (RSB) underflow issue. The 2535 mitigation is off by default and needs to be enabled on the 2536 kernel command line via the retbleed=stuff option. For 2537 non-affected systems the overhead of this option is marginal as 2538 the call depth tracking is using run-time generated call thunks 2539 in a compiler generated padding area and call patching. This 2540 increases text size by ~5%. For non affected systems this space 2541 is unused. On affected SKL systems this results in a significant 2542 performance gain over the IBRS mitigation. 2543 2544config CALL_THUNKS_DEBUG 2545 bool "Enable call thunks and call depth tracking debugging" |
| 2546 depends on CALL_DEPTH_TRACKING | 2546 depends on MITIGATION_CALL_DEPTH_TRACKING |
| 2547 select FUNCTION_ALIGNMENT_32B 2548 default n 2549 help 2550 Enable call/ret counters for imbalance detection and build in 2551 a noisy dmesg about callthunks generation and call patching for 2552 trouble shooting. The debug prints need to be enabled on the 2553 kernel command line with 'debug-callthunks'. 2554 Only enable this when you are debugging call thunks as this --- 486 unchanged lines hidden --- | 2547 select FUNCTION_ALIGNMENT_32B 2548 default n 2549 help 2550 Enable call/ret counters for imbalance detection and build in 2551 a noisy dmesg about callthunks generation and call patching for 2552 trouble shooting. The debug prints need to be enabled on the 2553 kernel command line with 'debug-callthunks'. 2554 Only enable this when you are debugging call thunks as this --- 486 unchanged lines hidden --- |