ed1cd6deb0
This patch activates CONFIG_THREAD_INFO_IN_TASK which
moves the thread_info into task_struct.
Moving thread_info into task_struct has the following advantages:
- It protects thread_info from corruption in the case of stack
overflows.
- Its address is harder to determine if stack addresses are leaked,
making a number of attacks more difficult.
This has the following consequences:
- thread_info is now located at the beginning of task_struct.
- The 'cpu' field is now in task_struct, and only exists when
CONFIG_SMP is active.
- thread_info doesn't have anymore the 'task' field.
This patch:
- Removes all recopy of thread_info struct when the stack changes.
- Changes the CURRENT_THREAD_INFO() macro to point to current.
- Selects CONFIG_THREAD_INFO_IN_TASK.
- Modifies raw_smp_processor_id() to get ->cpu from current without
including linux/sched.h to avoid circular inclusion and without
including asm/asm-offsets.h to avoid symbol names duplication
between ASM constants and C constants.
- Modifies klp_init_thread_info() to take a task_struct pointer
argument.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
[mpe: Add task_stack.h to livepatch.h to fix build fails]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
140 lines
3.8 KiB
C
140 lines
3.8 KiB
C
/*
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* bpf_jit32.h: BPF JIT compiler for PPC
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*
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* Copyright 2011 Matt Evans <matt@ozlabs.org>, IBM Corporation
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*
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* Split from bpf_jit.h
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; version 2
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* of the License.
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*/
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#ifndef _BPF_JIT32_H
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#define _BPF_JIT32_H
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#include <asm/asm-compat.h>
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#include "bpf_jit.h"
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#ifdef CONFIG_PPC64
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#define BPF_PPC_STACK_R3_OFF 48
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#define BPF_PPC_STACK_LOCALS 32
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#define BPF_PPC_STACK_BASIC (48+64)
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#define BPF_PPC_STACK_SAVE (18*8)
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#define BPF_PPC_STACKFRAME (BPF_PPC_STACK_BASIC+BPF_PPC_STACK_LOCALS+ \
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BPF_PPC_STACK_SAVE)
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#define BPF_PPC_SLOWPATH_FRAME (48+64)
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#else
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#define BPF_PPC_STACK_R3_OFF 24
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#define BPF_PPC_STACK_LOCALS 16
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#define BPF_PPC_STACK_BASIC (24+32)
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#define BPF_PPC_STACK_SAVE (18*4)
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#define BPF_PPC_STACKFRAME (BPF_PPC_STACK_BASIC+BPF_PPC_STACK_LOCALS+ \
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BPF_PPC_STACK_SAVE)
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#define BPF_PPC_SLOWPATH_FRAME (24+32)
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#endif
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#define REG_SZ (BITS_PER_LONG/8)
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/*
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* Generated code register usage:
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*
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* As normal PPC C ABI (e.g. r1=sp, r2=TOC), with:
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*
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* skb r3 (Entry parameter)
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* A register r4
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* X register r5
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* addr param r6
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* r7-r10 scratch
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* skb->data r14
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* skb headlen r15 (skb->len - skb->data_len)
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* m[0] r16
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* m[...] ...
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* m[15] r31
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*/
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#define r_skb 3
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#define r_ret 3
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#define r_A 4
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#define r_X 5
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#define r_addr 6
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#define r_scratch1 7
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#define r_scratch2 8
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#define r_D 14
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#define r_HL 15
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#define r_M 16
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#ifndef __ASSEMBLY__
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/*
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* Assembly helpers from arch/powerpc/net/bpf_jit.S:
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*/
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#define DECLARE_LOAD_FUNC(func) \
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extern u8 func[], func##_negative_offset[], func##_positive_offset[]
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DECLARE_LOAD_FUNC(sk_load_word);
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DECLARE_LOAD_FUNC(sk_load_half);
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DECLARE_LOAD_FUNC(sk_load_byte);
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DECLARE_LOAD_FUNC(sk_load_byte_msh);
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#define PPC_LBZ_OFFS(r, base, i) do { if ((i) < 32768) PPC_LBZ(r, base, i); \
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else { PPC_ADDIS(r, base, IMM_HA(i)); \
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PPC_LBZ(r, r, IMM_L(i)); } } while(0)
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#define PPC_LD_OFFS(r, base, i) do { if ((i) < 32768) PPC_LD(r, base, i); \
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else { PPC_ADDIS(r, base, IMM_HA(i)); \
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PPC_LD(r, r, IMM_L(i)); } } while(0)
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#define PPC_LWZ_OFFS(r, base, i) do { if ((i) < 32768) PPC_LWZ(r, base, i); \
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else { PPC_ADDIS(r, base, IMM_HA(i)); \
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PPC_LWZ(r, r, IMM_L(i)); } } while(0)
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#define PPC_LHZ_OFFS(r, base, i) do { if ((i) < 32768) PPC_LHZ(r, base, i); \
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else { PPC_ADDIS(r, base, IMM_HA(i)); \
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PPC_LHZ(r, r, IMM_L(i)); } } while(0)
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#ifdef CONFIG_PPC64
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#define PPC_LL_OFFS(r, base, i) do { PPC_LD_OFFS(r, base, i); } while(0)
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#else
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#define PPC_LL_OFFS(r, base, i) do { PPC_LWZ_OFFS(r, base, i); } while(0)
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#endif
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#ifdef CONFIG_SMP
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#ifdef CONFIG_PPC64
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#define PPC_BPF_LOAD_CPU(r) \
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do { BUILD_BUG_ON(FIELD_SIZEOF(struct paca_struct, paca_index) != 2); \
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PPC_LHZ_OFFS(r, 13, offsetof(struct paca_struct, paca_index)); \
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} while (0)
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#else
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#define PPC_BPF_LOAD_CPU(r) \
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do { BUILD_BUG_ON(FIELD_SIZEOF(struct task_struct, cpu) != 4); \
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PPC_LHZ_OFFS(r, 2, offsetof(struct task_struct, cpu)); \
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} while(0)
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#endif
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#else
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#define PPC_BPF_LOAD_CPU(r) do { PPC_LI(r, 0); } while(0)
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#endif
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#define PPC_LHBRX_OFFS(r, base, i) \
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do { PPC_LI32(r, i); PPC_LHBRX(r, r, base); } while(0)
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#ifdef __LITTLE_ENDIAN__
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#define PPC_NTOHS_OFFS(r, base, i) PPC_LHBRX_OFFS(r, base, i)
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#else
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#define PPC_NTOHS_OFFS(r, base, i) PPC_LHZ_OFFS(r, base, i)
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#endif
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#define SEEN_DATAREF 0x10000 /* might call external helpers */
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#define SEEN_XREG 0x20000 /* X reg is used */
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#define SEEN_MEM 0x40000 /* SEEN_MEM+(1<<n) = use mem[n] for temporary
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* storage */
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#define SEEN_MEM_MSK 0x0ffff
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struct codegen_context {
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unsigned int seen;
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unsigned int idx;
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int pc_ret0; /* bpf index of first RET #0 instruction (if any) */
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};
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#endif
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#endif
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