From a09a6e2399ba0595c3042b3164f3ca68a3cff33e Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Tue, 14 Jun 2022 23:16:03 +0200 Subject: objtool: Add entry UNRET validation Since entry asm is tricky, add a validation pass that ensures the retbleed mitigation has been done before the first actual RET instruction. Entry points are those that either have UNWIND_HINT_ENTRY, which acts as UNWIND_HINT_EMPTY but marks the instruction as an entry point, or those that have UWIND_HINT_IRET_REGS at +0. This is basically a variant of validate_branch() that is intra-function and it will simply follow all branches from marked entry points and ensures that all paths lead to ANNOTATE_UNRET_END. If a path hits RET or an indirection the path is a fail and will be reported. There are 3 ANNOTATE_UNRET_END instances: - UNTRAIN_RET itself - exception from-kernel; this path doesn't need UNTRAIN_RET - all early exceptions; these also don't need UNTRAIN_RET Signed-off-by: Peter Zijlstra (Intel) Signed-off-by: Borislav Petkov Reviewed-by: Josh Poimboeuf Signed-off-by: Borislav Petkov --- scripts/Makefile.vmlinux_o | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'scripts') diff --git a/scripts/Makefile.vmlinux_o b/scripts/Makefile.vmlinux_o index 3c97a1564947..bc67748044a6 100644 --- a/scripts/Makefile.vmlinux_o +++ b/scripts/Makefile.vmlinux_o @@ -44,7 +44,7 @@ objtool-enabled := $(or $(delay-objtool),$(CONFIG_NOINSTR_VALIDATION)) objtool_args := \ $(if $(delay-objtool),$(objtool_args)) \ - $(if $(CONFIG_NOINSTR_VALIDATION), --noinstr) \ + $(if $(CONFIG_NOINSTR_VALIDATION), --noinstr $(if $(CONFIG_RETPOLINE), --unret)) \ $(if $(CONFIG_GCOV_KERNEL), --no-unreachable) \ --link -- cgit v1.2.3 From f43b9876e857c739d407bc56df288b0ebe1a9164 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Mon, 27 Jun 2022 22:21:17 +0000 Subject: x86/retbleed: Add fine grained Kconfig knobs Do fine-grained Kconfig for all the various retbleed parts. NOTE: if your compiler doesn't support return thunks this will silently 'upgrade' your mitigation to IBPB, you might not like this. Signed-off-by: Peter Zijlstra (Intel) Signed-off-by: Borislav Petkov --- scripts/Makefile.lib | 1 + scripts/Makefile.vmlinux_o | 2 +- 2 files changed, 2 insertions(+), 1 deletion(-) (limited to 'scripts') diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib index d1425778664b..3fb6a99e78c4 100644 --- a/scripts/Makefile.lib +++ b/scripts/Makefile.lib @@ -236,6 +236,7 @@ objtool_args = \ $(if $(CONFIG_FTRACE_MCOUNT_USE_OBJTOOL), --mcount) \ $(if $(CONFIG_UNWINDER_ORC), --orc) \ $(if $(CONFIG_RETPOLINE), --retpoline) \ + $(if $(CONFIG_RETHUNK), --rethunk) \ $(if $(CONFIG_SLS), --sls) \ $(if $(CONFIG_STACK_VALIDATION), --stackval) \ $(if $(CONFIG_HAVE_STATIC_CALL_INLINE), --static-call) \ diff --git a/scripts/Makefile.vmlinux_o b/scripts/Makefile.vmlinux_o index bc67748044a6..84019814f33f 100644 --- a/scripts/Makefile.vmlinux_o +++ b/scripts/Makefile.vmlinux_o @@ -44,7 +44,7 @@ objtool-enabled := $(or $(delay-objtool),$(CONFIG_NOINSTR_VALIDATION)) objtool_args := \ $(if $(delay-objtool),$(objtool_args)) \ - $(if $(CONFIG_NOINSTR_VALIDATION), --noinstr $(if $(CONFIG_RETPOLINE), --unret)) \ + $(if $(CONFIG_NOINSTR_VALIDATION), --noinstr $(if $(CONFIG_CPU_UNRET_ENTRY), --unret)) \ $(if $(CONFIG_GCOV_KERNEL), --no-unreachable) \ --link -- cgit v1.2.3 From 23a67619bc7e12e1b3776802f16084530b357a5d Mon Sep 17 00:00:00 2001 From: Khalid Masum Date: Thu, 21 Jul 2022 15:30:42 +0600 Subject: scripts/gdb: Fix gdb 'lx-symbols' command Currently the command 'lx-symbols' in gdb exits with the error`Function "do_init_module" not defined in "kernel/module.c"`. This occurs because the file kernel/module.c was moved to kernel/module/main.c. Fix this breakage by changing the path to "kernel/module/main.c" in LoadModuleBreakpoint. Signed-off-by: Khalid Masum Acked-by: Luis Chamberlain Fixes: cfc1d277891e ("module: Move all into module/") Reviewed-by: Douglas Anderson Signed-off-by: Linus Torvalds --- scripts/gdb/linux/symbols.py | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'scripts') diff --git a/scripts/gdb/linux/symbols.py b/scripts/gdb/linux/symbols.py index 46f7542db08c..dc07b6d12e30 100644 --- a/scripts/gdb/linux/symbols.py +++ b/scripts/gdb/linux/symbols.py @@ -180,7 +180,7 @@ lx-symbols command.""" self.breakpoint.delete() self.breakpoint = None self.breakpoint = LoadModuleBreakpoint( - "kernel/module.c:do_init_module", self) + "kernel/module/main.c:do_init_module", self) else: gdb.write("Note: symbol update on module loading not supported " "with this gdb version\n") -- cgit v1.2.3