From: Deepak Gupta <debug@rivosinc.com>
To: linux-kernel@vger.kernel.org, linux-riscv@lists.infradead.org,
Paul Walmsley <paul.walmsley@sifive.com>,
Palmer Dabbelt <palmer@dabbelt.com>,
Albert Ou <aou@eecs.berkeley.edu>
Cc: Deepak Gupta <debug@rivosinc.com>
Subject: [PATCH v1 RFC Zisslpcfi 14/20] riscv: audit mode for cfi violations
Date: Sun, 12 Feb 2023 20:53:43 -0800 [thread overview]
Message-ID: <20230213045351.3945824-15-debug@rivosinc.com> (raw)
In-Reply-To: <20230213045351.3945824-1-debug@rivosinc.com>
Adding an audit mode per task which suppresses cfi violations reported
as illegal instruction exception.
Signed-off-by: Deepak Gupta <debug@rivosinc.com>
---
arch/riscv/include/asm/processor.h | 3 ++-
arch/riscv/kernel/process.c | 2 ++
arch/riscv/kernel/traps.c | 7 ++++++-
3 files changed, 10 insertions(+), 2 deletions(-)
diff --git a/arch/riscv/include/asm/processor.h b/arch/riscv/include/asm/processor.h
index f065309927b1..39c36f739ebb 100644
--- a/arch/riscv/include/asm/processor.h
+++ b/arch/riscv/include/asm/processor.h
@@ -45,7 +45,8 @@ struct thread_struct {
struct cfi_status {
unsigned int ufcfi_en : 1; /* Enable for forward cfi. Note that ELP goes in sstatus */
unsigned int ubcfi_en : 1; /* Enable for backward cfi. */
- unsigned int rsvd1 : 30;
+ unsigned int audit_mode : 1;
+ unsigned int rsvd1 : 29;
unsigned int lp_label; /* saved label value (25bit) */
long user_shdw_stk; /* Current user shadow stack pointer */
long shdw_stk_base; /* Base address of shadow stack */
diff --git a/arch/riscv/kernel/process.c b/arch/riscv/kernel/process.c
index db676262e61e..bfd8511914d9 100644
--- a/arch/riscv/kernel/process.c
+++ b/arch/riscv/kernel/process.c
@@ -246,11 +246,13 @@ int arch_elf_setup_cfi_state(const struct arch_elf_state *state)
info->user_cfi_state.user_shdw_stk = (shadow_stack_base + shadow_stk_size);
info->user_cfi_state.shdw_stk_base = shadow_stack_base;
+ info->user_cfi_state.audit_mode = 1;
}
/* setup forward cfi state */
if (arch_supports_indirect_br_lp_instr() && (state->flags & RISCV_ELF_FCFI)) {
info->user_cfi_state.ufcfi_en = 1;
info->user_cfi_state.lp_label = 0;
+ info->user_cfi_state.audit_mode = 1;
}
return ret;
diff --git a/arch/riscv/kernel/traps.c b/arch/riscv/kernel/traps.c
index a292699f4f25..1901a8b73de5 100644
--- a/arch/riscv/kernel/traps.c
+++ b/arch/riscv/kernel/traps.c
@@ -165,6 +165,7 @@ int handle_illegal_instruction(struct pt_regs *regs)
if (arch_supports_indirect_br_lp_instr() &&
#ifdef CONFIG_USER_INDIRECT_BR_LP
info->user_cfi_state.ufcfi_en &&
+ info->user_cfi_state.audit_mode &&
#endif
(regs->status & SR_ELP)) {
pr_warn("cfi violation (elp): comm = %s, task = %p\n", task->comm, task);
@@ -172,7 +173,11 @@ int handle_illegal_instruction(struct pt_regs *regs)
return 0;
}
/* if faulting opcode is sscheckra/lpcll/lpcml/lpcll, advance PC and resume */
- if (is_cfi_violation_insn(insn)) {
+ if (is_cfi_violation_insn(insn)
+#if defined(CONFIG_USER_SHADOW_STACK) || defined(CONFIG_USER_INDIRECT_BR_LP)
+ && info->user_cfi_state.audit_mode
+#endif
+ ) {
/* no compressed form for zisslpcfi instructions */
regs->epc += 4;
return 0;
--
2.25.1
next prev parent reply other threads:[~2023-02-13 4:55 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-02-13 4:53 [PATCH v1 RFC Zisslpcfi 00/20] riscv control-flow integrity for U mode Deepak Gupta
2023-02-13 4:53 ` [PATCH v1 RFC Zisslpcfi 01/20] sslp stubs: shadow stack and landing pad stubs Deepak Gupta
2023-02-13 4:53 ` [PATCH v1 RFC Zisslpcfi 02/20] riscv: zisslpcfi enumeration Deepak Gupta
2023-02-13 4:53 ` [PATCH v1 RFC Zisslpcfi 03/20] riscv: zisslpcfi extension csr and bit definitions Deepak Gupta
2023-02-13 4:53 ` [PATCH v1 RFC Zisslpcfi 04/20] riscv: kernel enabling user code for shadow stack and landing pad Deepak Gupta
2023-02-13 4:53 ` [PATCH v1 RFC Zisslpcfi 05/20] mmap : Introducing new protection "PROT_SHADOWSTACK" for mmap Deepak Gupta
2023-02-13 4:53 ` [PATCH v1 RFC Zisslpcfi 06/20] riscv: Implementing "PROT_SHADOWSTACK" on riscv Deepak Gupta
2023-02-13 4:53 ` [PATCH v1 RFC Zisslpcfi 07/20] elf: ELF header parsing in GNU property for cfi state Deepak Gupta
2023-02-13 4:53 ` [PATCH v1 RFC Zisslpcfi 08/20] riscv: ELF header parsing in GNU property for riscv zisslpcfi Deepak Gupta
2023-02-13 4:53 ` [PATCH v1 RFC Zisslpcfi 09/20] riscv mmu: riscv shadow stack page fault handling Deepak Gupta
2023-02-13 4:53 ` [PATCH v1 RFC Zisslpcfi 10/20] riscv mmu: write protect and shadow stack Deepak Gupta
2023-02-13 4:53 ` [PATCH v1 RFC Zisslpcfi 11/20] mmu: maybe_mkwrite updated to manufacture shadow stack PTEs Deepak Gupta
2023-02-13 12:05 ` David Hildenbrand
2023-02-13 14:37 ` Deepak Gupta
2023-02-13 14:56 ` David Hildenbrand
2023-02-13 20:01 ` Deepak Gupta
2023-02-14 12:10 ` David Hildenbrand
2023-02-14 18:27 ` Edgecombe, Rick P
2023-02-13 4:53 ` [PATCH v1 RFC Zisslpcfi 12/20] riscv mm: manufacture shadow stack pte and is vma shadowstack Deepak Gupta
2023-02-13 4:53 ` [PATCH v1 RFC Zisslpcfi 13/20] riscv: illegal instruction handler for cfi violations Deepak Gupta
2023-02-13 4:53 ` Deepak Gupta [this message]
2023-02-13 4:53 ` [PATCH v1 RFC Zisslpcfi 15/20] sslp prctl: arch-agnostic prctl for shadow stack and landing pad instr Deepak Gupta
2023-05-25 17:17 ` Mark Brown
2023-06-07 20:22 ` Mark Brown
2023-10-09 21:22 ` Deepak Gupta
2023-10-10 16:17 ` Mark Brown
2023-02-13 4:53 ` [PATCH v1 RFC Zisslpcfi 16/20] riscv: Implements sslp prctls Deepak Gupta
2023-02-13 4:53 ` [PATCH v1 RFC Zisslpcfi 17/20] riscv ucontext: adding shadow stack pointer field in ucontext Deepak Gupta
2023-02-13 4:53 ` [PATCH v1 RFC Zisslpcfi 18/20] riscv signal: Save and restore of shadow stack for signal Deepak Gupta
2023-02-13 4:53 ` [PATCH v1 RFC Zisslpcfi 19/20] config: adding two new config for control flow integrity Deepak Gupta
2023-02-13 4:53 ` [PATCH v1 RFC Zisslpcfi 20/20] riscv: select config for shadow stack and landing pad instr support Deepak Gupta
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