Messages in this thread Patch in this message | | | From | Deepak Gupta <> | Subject | [RFC PATCH 06/12] scs: place init shadow stack in .shadowstack section | Date | Mon, 8 Apr 2024 23:10:37 -0700 |
| |
If compiled for riscv and dynamic scs is turned on, place shadow stack in `.shadowstack` section. Arch specific linker script can place logic to protect this section against regular stores.
Signed-off-by: Deepak Gupta <debug@rivosinc.com> --- include/linux/init_task.h | 5 +++++ init/init_task.c | 12 ++++++++++-- 2 files changed, 15 insertions(+), 2 deletions(-)
diff --git a/include/linux/init_task.h b/include/linux/init_task.h index bccb3f1f6262..f025022e1164 100644 --- a/include/linux/init_task.h +++ b/include/linux/init_task.h @@ -40,4 +40,9 @@ extern struct cred init_cred; /* Attach to the thread_info data structure for proper alignment */ #define __init_thread_info __section(".data..init_thread_info") +#if defined(CONFIG_RISCV) && defined(CONFIG_DYNAMIC_SCS) +/* init shadow stack page */ +#define __init_shadow_stack __section(".shadowstack..init") +#endif + #endif diff --git a/init/init_task.c b/init/init_task.c index 4daee6d761c8..3c0a01455978 100644 --- a/init/init_task.c +++ b/init/init_task.c @@ -52,10 +52,18 @@ static struct sighand_struct init_sighand = { }; #ifdef CONFIG_SHADOW_CALL_STACK -unsigned long init_shadow_call_stack[SCS_SIZE / sizeof(long)] = { +unsigned long init_shadow_call_stack[SCS_SIZE / sizeof(long)] +#if defined(CONFIG_RISCV) && defined(CONFIG_DYNAMIC_SCS) + /* RISC-V dynamic SCS implements shadow stack and must go in special section */ + __init_shadow_stack = { + [0] = SCS_END_MAGIC +}; +#else + = { [(SCS_SIZE / sizeof(long)) - 1] = SCS_END_MAGIC }; -#endif +#endif /* CONFIG_RISCV && CONFIG_DYNAMIC_SCS */ +#endif /* CONFIG_SHADOW_CALL_STACK */ /* * Set up the first task table, touch at your own risk!. Base=0, -- 2.43.2
| |