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Message-Id: <20220429203644.2868448-11-samitolvanen@google.com>
Date: Fri, 29 Apr 2022 13:36:33 -0700
From: Sami Tolvanen <samitolvanen@...gle.com>
To: linux-kernel@...r.kernel.org
Cc: Kees Cook <keescook@...omium.org>,
Josh Poimboeuf <jpoimboe@...hat.com>,
Peter Zijlstra <peterz@...radead.org>, x86@...nel.org,
Catalin Marinas <catalin.marinas@....com>,
Will Deacon <will@...nel.org>,
Mark Rutland <mark.rutland@....com>,
Nathan Chancellor <nathan@...nel.org>,
Nick Desaulniers <ndesaulniers@...gle.com>,
Joao Moreira <joao@...rdrivepizza.com>,
Sedat Dilek <sedat.dilek@...il.com>,
Steven Rostedt <rostedt@...dmis.org>,
linux-hardening@...r.kernel.org,
linux-arm-kernel@...ts.infradead.org, llvm@...ts.linux.dev,
Sami Tolvanen <samitolvanen@...gle.com>
Subject: [RFC PATCH 10/21] treewide: Drop function_nocfi
With -fsanitize=kcfi, we no longer need function_nocfi() as
the compiler won't change function references to point to a
jump table. Remove all implementations and uses of the macro.
Signed-off-by: Sami Tolvanen <samitolvanen@...gle.com>
---
arch/arm64/include/asm/compiler.h | 16 ----------------
arch/arm64/include/asm/ftrace.h | 2 +-
arch/arm64/include/asm/mmu_context.h | 2 +-
arch/arm64/kernel/acpi_parking_protocol.c | 2 +-
arch/arm64/kernel/cpufeature.c | 2 +-
arch/arm64/kernel/ftrace.c | 2 +-
arch/arm64/kernel/machine_kexec.c | 2 +-
arch/arm64/kernel/psci.c | 2 +-
arch/arm64/kernel/smp_spin_table.c | 2 +-
drivers/firmware/psci/psci.c | 4 ++--
drivers/misc/lkdtm/usercopy.c | 2 +-
include/linux/compiler.h | 10 ----------
12 files changed, 11 insertions(+), 37 deletions(-)
diff --git a/arch/arm64/include/asm/compiler.h b/arch/arm64/include/asm/compiler.h
index dc3ea4080e2e..6fb2e6bcc392 100644
--- a/arch/arm64/include/asm/compiler.h
+++ b/arch/arm64/include/asm/compiler.h
@@ -23,20 +23,4 @@
#define __builtin_return_address(val) \
(void *)(ptrauth_clear_pac((unsigned long)__builtin_return_address(val)))
-#ifdef CONFIG_CFI_CLANG
-/*
- * With CONFIG_CFI_CLANG, the compiler replaces function address
- * references with the address of the function's CFI jump table
- * entry. The function_nocfi macro always returns the address of the
- * actual function instead.
- */
-#define function_nocfi(x) ({ \
- void *addr; \
- asm("adrp %0, " __stringify(x) "\n\t" \
- "add %0, %0, :lo12:" __stringify(x) \
- : "=r" (addr)); \
- addr; \
-})
-#endif
-
#endif /* __ASM_COMPILER_H */
diff --git a/arch/arm64/include/asm/ftrace.h b/arch/arm64/include/asm/ftrace.h
index 1494cfa8639b..c96d47cb8f46 100644
--- a/arch/arm64/include/asm/ftrace.h
+++ b/arch/arm64/include/asm/ftrace.h
@@ -26,7 +26,7 @@
#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
#define ARCH_SUPPORTS_FTRACE_OPS 1
#else
-#define MCOUNT_ADDR ((unsigned long)function_nocfi(_mcount))
+#define MCOUNT_ADDR ((unsigned long)_mcount)
#endif
/* The BL at the callsite's adjusted rec->ip */
diff --git a/arch/arm64/include/asm/mmu_context.h b/arch/arm64/include/asm/mmu_context.h
index 6770667b34a3..c9df5ab2c448 100644
--- a/arch/arm64/include/asm/mmu_context.h
+++ b/arch/arm64/include/asm/mmu_context.h
@@ -164,7 +164,7 @@ static inline void __nocfi cpu_replace_ttbr1(pgd_t *pgdp)
ttbr1 |= TTBR_CNP_BIT;
}
- replace_phys = (void *)__pa_symbol(function_nocfi(idmap_cpu_replace_ttbr1));
+ replace_phys = (void *)__pa_symbol(idmap_cpu_replace_ttbr1);
cpu_install_idmap();
replace_phys(ttbr1);
diff --git a/arch/arm64/kernel/acpi_parking_protocol.c b/arch/arm64/kernel/acpi_parking_protocol.c
index bfeeb5319abf..b1990e38aed0 100644
--- a/arch/arm64/kernel/acpi_parking_protocol.c
+++ b/arch/arm64/kernel/acpi_parking_protocol.c
@@ -99,7 +99,7 @@ static int acpi_parking_protocol_cpu_boot(unsigned int cpu)
* that read this address need to convert this address to the
* Boot-Loader's endianness before jumping.
*/
- writeq_relaxed(__pa_symbol(function_nocfi(secondary_entry)),
+ writeq_relaxed(__pa_symbol(secondary_entry),
&mailbox->entry_point);
writel_relaxed(cpu_entry->gic_cpu_id, &mailbox->cpu_id);
diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c
index d72c4b4d389c..dae07d99508b 100644
--- a/arch/arm64/kernel/cpufeature.c
+++ b/arch/arm64/kernel/cpufeature.c
@@ -1619,7 +1619,7 @@ kpti_install_ng_mappings(const struct arm64_cpu_capabilities *__unused)
if (arm64_use_ng_mappings)
return;
- remap_fn = (void *)__pa_symbol(function_nocfi(idmap_kpti_install_ng_mappings));
+ remap_fn = (void *)__pa_symbol(idmap_kpti_install_ng_mappings);
cpu_install_idmap();
remap_fn(cpu, num_online_cpus(), __pa_symbol(swapper_pg_dir));
diff --git a/arch/arm64/kernel/ftrace.c b/arch/arm64/kernel/ftrace.c
index 4506c4a90ac1..4128ca6ed485 100644
--- a/arch/arm64/kernel/ftrace.c
+++ b/arch/arm64/kernel/ftrace.c
@@ -56,7 +56,7 @@ int ftrace_update_ftrace_func(ftrace_func_t func)
unsigned long pc;
u32 new;
- pc = (unsigned long)function_nocfi(ftrace_call);
+ pc = (unsigned long)ftrace_call;
new = aarch64_insn_gen_branch_imm(pc, (unsigned long)func,
AARCH64_INSN_BRANCH_LINK);
diff --git a/arch/arm64/kernel/machine_kexec.c b/arch/arm64/kernel/machine_kexec.c
index e16b248699d5..4eb5388aa5a6 100644
--- a/arch/arm64/kernel/machine_kexec.c
+++ b/arch/arm64/kernel/machine_kexec.c
@@ -204,7 +204,7 @@ void machine_kexec(struct kimage *kimage)
typeof(cpu_soft_restart) *restart;
cpu_install_idmap();
- restart = (void *)__pa_symbol(function_nocfi(cpu_soft_restart));
+ restart = (void *)__pa_symbol(cpu_soft_restart);
restart(is_hyp_nvhe(), kimage->start, kimage->arch.dtb_mem,
0, 0);
} else {
diff --git a/arch/arm64/kernel/psci.c b/arch/arm64/kernel/psci.c
index ab7f4c476104..29a8e444db83 100644
--- a/arch/arm64/kernel/psci.c
+++ b/arch/arm64/kernel/psci.c
@@ -38,7 +38,7 @@ static int __init cpu_psci_cpu_prepare(unsigned int cpu)
static int cpu_psci_cpu_boot(unsigned int cpu)
{
- phys_addr_t pa_secondary_entry = __pa_symbol(function_nocfi(secondary_entry));
+ phys_addr_t pa_secondary_entry = __pa_symbol(secondary_entry);
int err = psci_ops.cpu_on(cpu_logical_map(cpu), pa_secondary_entry);
if (err)
pr_err("failed to boot CPU%d (%d)\n", cpu, err);
diff --git a/arch/arm64/kernel/smp_spin_table.c b/arch/arm64/kernel/smp_spin_table.c
index 7e1624ecab3c..49029eace3ad 100644
--- a/arch/arm64/kernel/smp_spin_table.c
+++ b/arch/arm64/kernel/smp_spin_table.c
@@ -66,7 +66,7 @@ static int smp_spin_table_cpu_init(unsigned int cpu)
static int smp_spin_table_cpu_prepare(unsigned int cpu)
{
__le64 __iomem *release_addr;
- phys_addr_t pa_holding_pen = __pa_symbol(function_nocfi(secondary_holding_pen));
+ phys_addr_t pa_holding_pen = __pa_symbol(secondary_holding_pen);
if (!cpu_release_addr[cpu])
return -ENODEV;
diff --git a/drivers/firmware/psci/psci.c b/drivers/firmware/psci/psci.c
index cfb448eabdaa..aa3133cafced 100644
--- a/drivers/firmware/psci/psci.c
+++ b/drivers/firmware/psci/psci.c
@@ -334,7 +334,7 @@ static int __init psci_features(u32 psci_func_id)
static int psci_suspend_finisher(unsigned long state)
{
u32 power_state = state;
- phys_addr_t pa_cpu_resume = __pa_symbol(function_nocfi(cpu_resume));
+ phys_addr_t pa_cpu_resume = __pa_symbol(cpu_resume);
return psci_ops.cpu_suspend(power_state, pa_cpu_resume);
}
@@ -359,7 +359,7 @@ int psci_cpu_suspend_enter(u32 state)
static int psci_system_suspend(unsigned long unused)
{
- phys_addr_t pa_cpu_resume = __pa_symbol(function_nocfi(cpu_resume));
+ phys_addr_t pa_cpu_resume = __pa_symbol(cpu_resume);
return invoke_psci_fn(PSCI_FN_NATIVE(1_0, SYSTEM_SUSPEND),
pa_cpu_resume, 0, 0);
diff --git a/drivers/misc/lkdtm/usercopy.c b/drivers/misc/lkdtm/usercopy.c
index 9161ce7ed47a..79a17b1c4885 100644
--- a/drivers/misc/lkdtm/usercopy.c
+++ b/drivers/misc/lkdtm/usercopy.c
@@ -318,7 +318,7 @@ void lkdtm_USERCOPY_KERNEL(void)
pr_info("attempting bad copy_to_user from kernel text: %px\n",
vm_mmap);
- if (copy_to_user((void __user *)user_addr, function_nocfi(vm_mmap),
+ if (copy_to_user((void __user *)user_addr, vm_mmap,
unconst + PAGE_SIZE)) {
pr_warn("copy_to_user failed, but lacked Oops\n");
goto free_user;
diff --git a/include/linux/compiler.h b/include/linux/compiler.h
index 9303f5fe5d89..80ed9644d129 100644
--- a/include/linux/compiler.h
+++ b/include/linux/compiler.h
@@ -203,16 +203,6 @@ void ftrace_likely_update(struct ftrace_likely_data *f, int val,
__v; \
})
-/*
- * With CONFIG_CFI_CLANG, the compiler replaces function addresses in
- * instrumented C code with jump table addresses. Architectures that
- * support CFI can define this macro to return the actual function address
- * when needed.
- */
-#ifndef function_nocfi
-#define function_nocfi(x) (x)
-#endif
-
#endif /* __KERNEL__ */
/*
--
2.36.0.464.gb9c8b46e94-goog
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