mirror of
git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
synced 2025-08-05 16:54:27 +00:00
a45728fd41
Add support for the stackleak feature. It initializes the stack with the
poison value before returning from system calls which improves the kernel
security.
At the same time, disables the plugin in EFI stub code because EFI stub
is out of scope for the protection.
Tested on Loongson-3A5000 (enable GCC_PLUGIN_STACKLEAK and LKDTM):
# echo STACKLEAK_ERASING > /sys/kernel/debug/provoke-crash/DIRECT
# dmesg
lkdtm: Performing direct entry STACKLEAK_ERASING
lkdtm: stackleak stack usage:
high offset: 320 bytes
current: 448 bytes
lowest: 1264 bytes
tracked: 1264 bytes
untracked: 208 bytes
poisoned: 14528 bytes
low offset: 64 bytes
lkdtm: OK: the rest of the thread stack is properly erased
Signed-off-by: Youling Tang <tangyouling@kylinos.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
102 lines
2.7 KiB
C
102 lines
2.7 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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/*
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* Copyright (C) 2020-2022 Loongson Technology Corporation Limited
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*/
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#ifndef _ASM_STACKTRACE_H
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#define _ASM_STACKTRACE_H
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#include <asm/asm.h>
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#include <asm/ptrace.h>
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#include <asm/loongarch.h>
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#include <asm/unwind_hints.h>
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#include <linux/stringify.h>
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enum stack_type {
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STACK_TYPE_UNKNOWN,
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STACK_TYPE_IRQ,
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STACK_TYPE_TASK,
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};
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struct stack_info {
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enum stack_type type;
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unsigned long begin, end, next_sp;
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};
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struct stack_frame {
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unsigned long fp;
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unsigned long ra;
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};
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bool in_irq_stack(unsigned long stack, struct stack_info *info);
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bool in_task_stack(unsigned long stack, struct task_struct *task, struct stack_info *info);
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int get_stack_info(unsigned long stack, struct task_struct *task, struct stack_info *info);
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static __always_inline bool on_thread_stack(void)
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{
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return !(((unsigned long)(current->stack) ^ current_stack_pointer) & ~(THREAD_SIZE - 1));
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}
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#define STR_LONG_L __stringify(LONG_L)
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#define STR_LONG_S __stringify(LONG_S)
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#define STR_LONGSIZE __stringify(LONGSIZE)
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#define STORE_ONE_REG(r) \
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STR_LONG_S " $r" __stringify(r)", %1, "STR_LONGSIZE"*"__stringify(r)"\n\t"
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#define CSRRD_ONE_REG(reg) \
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__stringify(csrrd) " %0, "__stringify(reg)"\n\t"
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static __always_inline void prepare_frametrace(struct pt_regs *regs)
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{
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__asm__ __volatile__(
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UNWIND_HINT_SAVE
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/* Save $ra */
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STORE_ONE_REG(1)
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/* Use $ra to save PC */
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"pcaddi $ra, 0\n\t"
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STR_LONG_S " $ra, %0\n\t"
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/* Restore $ra */
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STR_LONG_L " $ra, %1, "STR_LONGSIZE"\n\t"
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STORE_ONE_REG(2)
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STORE_ONE_REG(3)
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STORE_ONE_REG(4)
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STORE_ONE_REG(5)
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STORE_ONE_REG(6)
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STORE_ONE_REG(7)
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STORE_ONE_REG(8)
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STORE_ONE_REG(9)
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STORE_ONE_REG(10)
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STORE_ONE_REG(11)
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STORE_ONE_REG(12)
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STORE_ONE_REG(13)
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STORE_ONE_REG(14)
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STORE_ONE_REG(15)
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STORE_ONE_REG(16)
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STORE_ONE_REG(17)
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STORE_ONE_REG(18)
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STORE_ONE_REG(19)
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STORE_ONE_REG(20)
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STORE_ONE_REG(21)
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STORE_ONE_REG(22)
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STORE_ONE_REG(23)
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STORE_ONE_REG(24)
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STORE_ONE_REG(25)
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STORE_ONE_REG(26)
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STORE_ONE_REG(27)
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STORE_ONE_REG(28)
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STORE_ONE_REG(29)
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STORE_ONE_REG(30)
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STORE_ONE_REG(31)
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UNWIND_HINT_RESTORE
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: "=m" (regs->csr_era)
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: "r" (regs->regs)
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: "memory");
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__asm__ __volatile__(CSRRD_ONE_REG(LOONGARCH_CSR_BADV) : "=r" (regs->csr_badvaddr));
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__asm__ __volatile__(CSRRD_ONE_REG(LOONGARCH_CSR_CRMD) : "=r" (regs->csr_crmd));
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__asm__ __volatile__(CSRRD_ONE_REG(LOONGARCH_CSR_PRMD) : "=r" (regs->csr_prmd));
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__asm__ __volatile__(CSRRD_ONE_REG(LOONGARCH_CSR_EUEN) : "=r" (regs->csr_euen));
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__asm__ __volatile__(CSRRD_ONE_REG(LOONGARCH_CSR_ECFG) : "=r" (regs->csr_ecfg));
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__asm__ __volatile__(CSRRD_ONE_REG(LOONGARCH_CSR_ESTAT) : "=r" (regs->csr_estat));
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}
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#endif /* _ASM_STACKTRACE_H */
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