From: Josh Poimboeuf <[email protected]> The kernel doesn't have direct visibility to the ELF contents of shared libraries. Add some prctl() interfaces which allow glibc to tell the kernel where to find .sframe sections.
[ This adds an interface for prctl() for testing loading of sframes for libraries. But this interface should really be a system call. This patch is for testing purposes only and should not be applied to mainline. ] Signed-off-by: Josh Poimboeuf <[email protected]> Signed-off-by: Steven Rostedt (Google) <[email protected]> Reviewed-by: Indu Bhagat <[email protected]> Signed-off-by: Jens Remus <[email protected]> --- Notes (jremus): Changes in v14: - Bump PR_ADD_SFRAME and PR_REMOVE_SFRAME. include/uapi/linux/prctl.h | 6 +++++- kernel/sys.c | 8 ++++++++ 2 files changed, 13 insertions(+), 1 deletion(-) diff --git a/include/uapi/linux/prctl.h b/include/uapi/linux/prctl.h index b6ec6f693719..0aa0ec971843 100644 --- a/include/uapi/linux/prctl.h +++ b/include/uapi/linux/prctl.h @@ -368,7 +368,7 @@ struct prctl_mm_map { * configuration. All bits may be locked via this call, including * undefined bits. */ -#define PR_LOCK_SHADOW_STACK_STATUS 76 +#define PR_LOCK_SHADOW_STACK_STATUS 76 /* * Controls the mode of timer_create() for CRIU restore operations. @@ -416,4 +416,8 @@ struct prctl_mm_map { # define PR_CFI_DISABLE _BITUL(1) # define PR_CFI_LOCK _BITUL(2) +/* SFRAME management */ +#define PR_ADD_SFRAME 82 +#define PR_REMOVE_SFRAME 83 + #endif /* _LINUX_PRCTL_H */ diff --git a/kernel/sys.c b/kernel/sys.c index 62e842055cc9..6e81e82bc991 100644 --- a/kernel/sys.c +++ b/kernel/sys.c @@ -65,6 +65,7 @@ #include <linux/rcupdate.h> #include <linux/uidgid.h> #include <linux/cred.h> +#include <linux/sframe.h> #include <linux/nospec.h> @@ -2906,6 +2907,13 @@ SYSCALL_DEFINE5(prctl, int, option, unsigned long, arg2, unsigned long, arg3, break; if (arg3 & PR_CFI_LOCK && !(arg3 & PR_CFI_DISABLE)) error = arch_prctl_lock_branch_landing_pad_state(me); + case PR_ADD_SFRAME: + error = sframe_add_section(arg2, arg3, arg4, arg5); + break; + case PR_REMOVE_SFRAME: + if (arg3 || arg4 || arg5) + return -EINVAL; + error = sframe_remove_section(arg2); break; default: trace_task_prctl_unknown(option, arg2, arg3, arg4, arg5); -- 2.51.0
