diff options
Diffstat (limited to 'arch/Kconfig')
| -rw-r--r-- | arch/Kconfig | 55 |
1 files changed, 55 insertions, 0 deletions
diff --git a/arch/Kconfig b/arch/Kconfig index ae80cd24e8f0..659bdd079277 100644 --- a/arch/Kconfig +++ b/arch/Kconfig @@ -468,6 +468,27 @@ config CC_STACKPROTECTOR_STRONG endchoice +config THIN_ARCHIVES + bool + help + Select this if the architecture wants to use thin archives + instead of ld -r to create the built-in.o files. + +config LD_DEAD_CODE_DATA_ELIMINATION + bool + help + Select this if the architecture wants to do dead code and + data elimination with the linker by compiling with + -ffunction-sections -fdata-sections and linking with + --gc-sections. + + This requires that the arch annotates or otherwise protects + its external entry points from being discarded. Linker scripts + must also merge .text.*, .data.*, and .bss.* correctly into + output sections. Care must be taken not to pull in unrelated + sections (e.g., '.text.init'). Typically '.' in section names + is used to distinguish them from label names / C identifiers. + config HAVE_ARCH_WITHIN_STACK_FRAMES bool help @@ -714,4 +735,38 @@ config ARCH_NO_COHERENT_DMA_MMAP config CPU_NO_EFFICIENT_FFS def_bool n +config HAVE_ARCH_VMAP_STACK + def_bool n + help + An arch should select this symbol if it can support kernel stacks + in vmalloc space. This means: + + - vmalloc space must be large enough to hold many kernel stacks. + This may rule out many 32-bit architectures. + + - Stacks in vmalloc space need to work reliably. For example, if + vmap page tables are created on demand, either this mechanism + needs to work while the stack points to a virtual address with + unpopulated page tables or arch code (switch_to() and switch_mm(), + most likely) needs to ensure that the stack's page table entries + are populated before running on a possibly unpopulated stack. + + - If the stack overflows into a guard page, something reasonable + should happen. The definition of "reasonable" is flexible, but + instantly rebooting without logging anything would be unfriendly. + +config VMAP_STACK + default y + bool "Use a virtually-mapped stack" + depends on HAVE_ARCH_VMAP_STACK && !KASAN + ---help--- + Enable this if you want the use virtually-mapped kernel stacks + with guard pages. This causes kernel stack overflows to be + caught immediately rather than causing difficult-to-diagnose + corruption. + + This is presently incompatible with KASAN because KASAN expects + the stack to map directly to the KASAN shadow map using a formula + that is incorrect if the stack is in vmalloc space. + source "kernel/gcov/Kconfig" |