Each application enables indirect branch tracking (forward cfi) for itself via prctl. Adding branch tracking prctl in linux-user/syscall.
Using same prctl code as proposed in cfi patches in kernel mailing list [1] [1] - https://lore.kernel.org/all/20240403234054.2020347-1-de...@rivosinc.com/ Signed-off-by: Deepak Gupta <de...@rivosinc.com> Co-developed-by: Jim Shu <jim....@sifive.com> Co-developed-by: Andy Chiu <andy.c...@sifive.com> Co-developed-by: Jesse Huang <jesse.hu...@sifive.com> --- linux-user/syscall.c | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+) diff --git a/linux-user/syscall.c b/linux-user/syscall.c index b8c278b91d..ec157c1088 100644 --- a/linux-user/syscall.c +++ b/linux-user/syscall.c @@ -6295,6 +6295,17 @@ abi_long do_arch_prctl(CPUX86State *env, int code, abi_ulong addr) # define PR_SME_VL_INHERIT (1 << 17) #endif +#ifndef PR_GET_INDIR_BR_LP_STATUS +# define PR_GET_INDIR_BR_LP_STATUS 74 +#endif +#ifndef PR_SET_INDIR_BR_LP_STATUS +# define PR_SET_INDIR_BR_LP_STATUS 75 +# define PR_INDIR_BR_LP_ENABLE (1UL << 0) +#endif +#ifndef PR_LOCK_INDIR_BR_LP_STATUS +# define PR_LOCK_INDIR_BR_LP_STATUS 76 +#endif + #include "target_prctl.h" static abi_long do_prctl_inval0(CPUArchState *env) @@ -6477,6 +6488,14 @@ static abi_long do_prctl(CPUArchState *env, abi_long option, abi_long arg2, case PR_SET_TSC: /* Disable to prevent the target disabling stuff we need. */ return -TARGET_EINVAL; + case PR_GET_INDIR_BR_LP_STATUS: + case PR_SET_INDIR_BR_LP_STATUS: + case PR_LOCK_INDIR_BR_LP_STATUS: +#ifndef do_prctl_cfi + return do_prctl_inval1(env, arg2); +#else + return do_prctl_cfi(env, option, arg2); +#endif default: qemu_log_mask(LOG_UNIMP, "Unsupported prctl: " TARGET_ABI_FMT_ld "\n", -- 2.44.0
