From 51ef2a4da7ec347e3315af69a426ac36fab98a6c Mon Sep 17 00:00:00 2001 From: "H. Peter Anvin (Intel)" Date: Tue, 5 Dec 2023 02:50:17 -0800 Subject: [PATCH] x86/fred: Let ret_from_fork_asm() jmp to asm_fred_exit_user when FRED is enabled Let ret_from_fork_asm() jmp to asm_fred_exit_user when FRED is enabled, otherwise the existing IDT code is chosen. Signed-off-by: H. Peter Anvin (Intel) Signed-off-by: Xin Li Signed-off-by: Thomas Gleixner Signed-off-by: Borislav Petkov (AMD) Tested-by: Shan Kang Link: https://lore.kernel.org/r/20231205105030.8698-29-xin3.li@intel.com --- arch/x86/entry/entry_64.S | 6 ++++++ arch/x86/entry/entry_64_fred.S | 1 + 2 files changed, 7 insertions(+) diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S index 29ce68f8ede04..7c4b7263b8571 100644 --- a/arch/x86/entry/entry_64.S +++ b/arch/x86/entry/entry_64.S @@ -247,7 +247,13 @@ SYM_CODE_START(ret_from_fork_asm) * and unwind should work normally. */ UNWIND_HINT_REGS + +#ifdef CONFIG_X86_FRED + ALTERNATIVE "jmp swapgs_restore_regs_and_return_to_usermode", \ + "jmp asm_fred_exit_user", X86_FEATURE_FRED +#else jmp swapgs_restore_regs_and_return_to_usermode +#endif SYM_CODE_END(ret_from_fork_asm) .popsection diff --git a/arch/x86/entry/entry_64_fred.S b/arch/x86/entry/entry_64_fred.S index c1ddaf6b068f4..2271a1c690dc6 100644 --- a/arch/x86/entry/entry_64_fred.S +++ b/arch/x86/entry/entry_64_fred.S @@ -32,6 +32,7 @@ SYM_CODE_START_NOALIGN(asm_fred_entrypoint_user) FRED_ENTER call fred_entry_from_user +SYM_INNER_LABEL(asm_fred_exit_user, SYM_L_GLOBAL) FRED_EXIT ERETU SYM_CODE_END(asm_fred_entrypoint_user) -- 2.30.2