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    Subject[PATCH 3/3] uprobes/core: move insn to arch specific structure.
    From: Srikar Dronamraju <srikar@linux.vnet.ibm.com>

    Few cleanups suggested by Ingo Molnar.

    - Rename struct uprobe_arch_info to struct arch_uprobe.
    - Move insn from struct uprobe to struct arch_uprobe.
    - Make arch specific uprobe functions to accept struct arch_uprobe instead of
    struct uprobe.
    - Move struct uprobe to kernel/uprobes.c from include/linux/uprobes.h

    Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
    ---
    arch/x86/include/asm/uprobes.h | 6 ++--
    arch/x86/kernel/uprobes.c | 60 ++++++++++++++++++++--------------------
    include/linux/uprobes.h | 23 +--------------
    kernel/uprobes.c | 38 +++++++++++++++++--------
    4 files changed, 61 insertions(+), 66 deletions(-)

    diff --git a/arch/x86/include/asm/uprobes.h b/arch/x86/include/asm/uprobes.h
    index 072df39..f7ce310 100644
    --- a/arch/x86/include/asm/uprobes.h
    +++ b/arch/x86/include/asm/uprobes.h
    @@ -31,13 +31,13 @@ typedef u8 uprobe_opcode_t;
    #define UPROBES_BKPT_INSN 0xcc
    #define UPROBES_BKPT_INSN_SIZE 1

    -struct uprobe_arch_info {
    +struct arch_uprobe {
    u16 fixups;
    + u8 insn[MAX_UINSN_BYTES];
    #ifdef CONFIG_X86_64
    unsigned long rip_rela_target_address;
    #endif
    };

    -struct uprobe;
    -extern int arch_uprobes_analyze_insn(struct mm_struct *mm, struct uprobe *uprobe);
    +extern int arch_uprobes_analyze_insn(struct mm_struct *mm, struct arch_uprobe *arch_uprobe);
    #endif /* _ASM_UPROBES_H */
    diff --git a/arch/x86/kernel/uprobes.c b/arch/x86/kernel/uprobes.c
    index 13d616d..04dfcef 100644
    --- a/arch/x86/kernel/uprobes.c
    +++ b/arch/x86/kernel/uprobes.c
    @@ -200,9 +200,9 @@ static bool is_prefix_bad(struct insn *insn)
    return false;
    }

    -static int validate_insn_32bits(struct uprobe *uprobe, struct insn *insn)
    +static int validate_insn_32bits(struct arch_uprobe *auprobe, struct insn *insn)
    {
    - insn_init(insn, uprobe->insn, false);
    + insn_init(insn, auprobe->insn, false);

    /* Skip good instruction prefixes; reject "bad" ones. */
    insn_get_opcode(insn);
    @@ -222,11 +222,11 @@ static int validate_insn_32bits(struct uprobe *uprobe, struct insn *insn)

    /*
    * Figure out which fixups post_xol() will need to perform, and annotate
    - * uprobe->arch_info.fixups accordingly. To start with,
    - * uprobe->arch_info.fixups is either zero or it reflects rip-related
    + * arch_uprobe->fixups accordingly. To start with,
    + * arch_uprobe->fixups is either zero or it reflects rip-related
    * fixups.
    */
    -static void prepare_fixups(struct uprobe *uprobe, struct insn *insn)
    +static void prepare_fixups(struct arch_uprobe *auprobe, struct insn *insn)
    {
    bool fix_ip = true, fix_call = false; /* defaults */
    int reg;
    @@ -269,17 +269,17 @@ static void prepare_fixups(struct uprobe *uprobe, struct insn *insn)
    break;
    }
    if (fix_ip)
    - uprobe->arch_info.fixups |= UPROBES_FIX_IP;
    + auprobe->fixups |= UPROBES_FIX_IP;
    if (fix_call)
    - uprobe->arch_info.fixups |= UPROBES_FIX_CALL;
    + auprobe->fixups |= UPROBES_FIX_CALL;
    }

    #ifdef CONFIG_X86_64
    /*
    - * If uprobe->insn doesn't use rip-relative addressing, return
    + * If arch_uprobe->insn doesn't use rip-relative addressing, return
    * immediately. Otherwise, rewrite the instruction so that it accesses
    * its memory operand indirectly through a scratch register. Set
    - * uprobe->arch_info.fixups and uprobe->arch_info.rip_rela_target_address
    + * arch_uprobe->fixups and arch_uprobe->rip_rela_target_address
    * accordingly. (The contents of the scratch register will be saved
    * before we single-step the modified instruction, and restored
    * afterward.)
    @@ -297,7 +297,7 @@ static void prepare_fixups(struct uprobe *uprobe, struct insn *insn)
    * - There's never a SIB byte.
    * - The displacement is always 4 bytes.
    */
    -static void handle_riprel_insn(struct mm_struct *mm, struct uprobe *uprobe, struct insn *insn)
    +static void handle_riprel_insn(struct mm_struct *mm, struct arch_uprobe *auprobe, struct insn *insn)
    {
    u8 *cursor;
    u8 reg;
    @@ -305,7 +305,7 @@ static void handle_riprel_insn(struct mm_struct *mm, struct uprobe *uprobe, stru
    if (mm->context.ia32_compat)
    return;

    - uprobe->arch_info.rip_rela_target_address = 0x0;
    + auprobe->rip_rela_target_address = 0x0;
    if (!insn_rip_relative(insn))
    return;

    @@ -315,7 +315,7 @@ static void handle_riprel_insn(struct mm_struct *mm, struct uprobe *uprobe, stru
    * we want to encode rax/rcx, not r8/r9.
    */
    if (insn->rex_prefix.nbytes) {
    - cursor = uprobe->insn + insn_offset_rex_prefix(insn);
    + cursor = auprobe->insn + insn_offset_rex_prefix(insn);
    *cursor &= 0xfe; /* Clearing REX.B bit */
    }

    @@ -324,7 +324,7 @@ static void handle_riprel_insn(struct mm_struct *mm, struct uprobe *uprobe, stru
    * displacement. Beyond the displacement, for some instructions,
    * is the immediate operand.
    */
    - cursor = uprobe->insn + insn_offset_modrm(insn);
    + cursor = auprobe->insn + insn_offset_modrm(insn);
    insn_get_length(insn);

    /*
    @@ -341,18 +341,18 @@ static void handle_riprel_insn(struct mm_struct *mm, struct uprobe *uprobe, stru
    * is NOT the register operand, so we use %rcx (register
    * #1) for the scratch register.
    */
    - uprobe->arch_info.fixups = UPROBES_FIX_RIP_CX;
    + auprobe->fixups = UPROBES_FIX_RIP_CX;
    /* Change modrm from 00 000 101 to 00 000 001. */
    *cursor = 0x1;
    } else {
    /* Use %rax (register #0) for the scratch register. */
    - uprobe->arch_info.fixups = UPROBES_FIX_RIP_AX;
    + auprobe->fixups = UPROBES_FIX_RIP_AX;
    /* Change modrm from 00 xxx 101 to 00 xxx 000 */
    *cursor = (reg << 3);
    }

    /* Target address = address of next instruction + (signed) offset */
    - uprobe->arch_info.rip_rela_target_address = (long)insn->length + insn->displacement.value;
    + auprobe->rip_rela_target_address = (long)insn->length + insn->displacement.value;

    /* Displacement field is gone; slide immediate field (if any) over. */
    if (insn->immediate.nbytes) {
    @@ -362,9 +362,9 @@ static void handle_riprel_insn(struct mm_struct *mm, struct uprobe *uprobe, stru
    return;
    }

    -static int validate_insn_64bits(struct uprobe *uprobe, struct insn *insn)
    +static int validate_insn_64bits(struct arch_uprobe *auprobe, struct insn *insn)
    {
    - insn_init(insn, uprobe->insn, true);
    + insn_init(insn, auprobe->insn, true);

    /* Skip good instruction prefixes; reject "bad" ones. */
    insn_get_opcode(insn);
    @@ -381,42 +381,42 @@ static int validate_insn_64bits(struct uprobe *uprobe, struct insn *insn)
    return -ENOTSUPP;
    }

    -static int validate_insn_bits(struct mm_struct *mm, struct uprobe *uprobe, struct insn *insn)
    +static int validate_insn_bits(struct mm_struct *mm, struct arch_uprobe *auprobe, struct insn *insn)
    {
    if (mm->context.ia32_compat)
    - return validate_insn_32bits(uprobe, insn);
    - return validate_insn_64bits(uprobe, insn);
    + return validate_insn_32bits(auprobe, insn);
    + return validate_insn_64bits(auprobe, insn);
    }
    #else /* 32-bit: */
    -static void handle_riprel_insn(struct mm_struct *mm, struct uprobe *uprobe, struct insn *insn)
    +static void handle_riprel_insn(struct mm_struct *mm, struct arch_uprobe *auprobe, struct insn *insn)
    {
    /* No RIP-relative addressing on 32-bit */
    }

    -static int validate_insn_bits(struct mm_struct *mm, struct uprobe *uprobe, struct insn *insn)
    +static int validate_insn_bits(struct mm_struct *mm, struct arch_uprobe *auprobe, struct insn *insn)
    {
    - return validate_insn_32bits(uprobe, insn);
    + return validate_insn_32bits(auprobe, insn);
    }
    #endif /* CONFIG_X86_64 */

    /**
    * arch_uprobes_analyze_insn - instruction analysis including validity and fixups.
    * @mm: the probed address space.
    - * @uprobe: the probepoint information.
    + * @arch_uprobe: the probepoint information.
    * Return 0 on success or a -ve number on error.
    */
    -int arch_uprobes_analyze_insn(struct mm_struct *mm, struct uprobe *uprobe)
    +int arch_uprobes_analyze_insn(struct mm_struct *mm, struct arch_uprobe *auprobe)
    {
    int ret;
    struct insn insn;

    - uprobe->arch_info.fixups = 0;
    - ret = validate_insn_bits(mm, uprobe, &insn);
    + auprobe->fixups = 0;
    + ret = validate_insn_bits(mm, auprobe, &insn);
    if (ret != 0)
    return ret;

    - handle_riprel_insn(mm, uprobe, &insn);
    - prepare_fixups(uprobe, &insn);
    + handle_riprel_insn(mm, auprobe, &insn);
    + prepare_fixups(auprobe, &insn);

    return 0;
    }
    diff --git a/include/linux/uprobes.h b/include/linux/uprobes.h
    index fd45b70..9c6be62 100644
    --- a/include/linux/uprobes.h
    +++ b/include/linux/uprobes.h
    @@ -29,12 +29,6 @@
    struct vm_area_struct;
    #ifdef CONFIG_ARCH_SUPPORTS_UPROBES
    #include <asm/uprobes.h>
    -#else
    -
    -typedef u8 uprobe_opcode_t;
    -struct uprobe_arch_info {};
    -
    -#define MAX_UINSN_BYTES 4
    #endif

    /* flags that denote/change uprobes behaviour */
    @@ -56,22 +50,9 @@ struct uprobe_consumer {
    struct uprobe_consumer *next;
    };

    -struct uprobe {
    - struct rb_node rb_node; /* node in the rb tree */
    - atomic_t ref;
    - struct rw_semaphore consumer_rwsem;
    - struct list_head pending_list;
    - struct uprobe_arch_info arch_info;
    - struct uprobe_consumer *consumers;
    - struct inode *inode; /* Also hold a ref to inode */
    - loff_t offset;
    - int flags;
    - u8 insn[MAX_UINSN_BYTES];
    -};
    -
    #ifdef CONFIG_UPROBES
    -extern int __weak set_bkpt(struct mm_struct *mm, struct uprobe *uprobe, unsigned long vaddr);
    -extern int __weak set_orig_insn(struct mm_struct *mm, struct uprobe *uprobe, unsigned long vaddr, bool verify);
    +extern int __weak set_bkpt(struct mm_struct *mm, struct arch_uprobe *auprobe, unsigned long vaddr);
    +extern int __weak set_orig_insn(struct mm_struct *mm, struct arch_uprobe *auprobe, unsigned long vaddr, bool verify);
    extern bool __weak is_bkpt_insn(uprobe_opcode_t *insn);
    extern int uprobe_register(struct inode *inode, loff_t offset, struct uprobe_consumer *consumer);
    extern void uprobe_unregister(struct inode *inode, loff_t offset, struct uprobe_consumer *consumer);
    diff --git a/kernel/uprobes.c b/kernel/uprobes.c
    index ee496ad..0867302 100644
    --- a/kernel/uprobes.c
    +++ b/kernel/uprobes.c
    @@ -65,6 +65,18 @@ struct vma_info {
    loff_t vaddr;
    };

    +struct uprobe {
    + struct rb_node rb_node; /* node in the rb tree */
    + atomic_t ref;
    + struct rw_semaphore consumer_rwsem;
    + struct list_head pending_list;
    + struct uprobe_consumer *consumers;
    + struct inode *inode; /* Also hold a ref to inode */
    + loff_t offset;
    + int flags;
    + struct arch_uprobe arch;
    +};
    +
    /*
    * valid_vma: Verify if the specified vma is an executable vma
    * Relax restrictions while unregistering: vm_flags might have
    @@ -180,7 +192,7 @@ bool __weak is_bkpt_insn(uprobe_opcode_t *insn)
    /*
    * write_opcode - write the opcode at a given virtual address.
    * @mm: the probed process address space.
    - * @uprobe: the breakpointing information.
    + * @arch_uprobe: the breakpointing information.
    * @vaddr: the virtual address to store the opcode.
    * @opcode: opcode to be written at @vaddr.
    *
    @@ -190,13 +202,14 @@ bool __weak is_bkpt_insn(uprobe_opcode_t *insn)
    * For mm @mm, write the opcode at @vaddr.
    * Return 0 (success) or a negative errno.
    */
    -static int write_opcode(struct mm_struct *mm, struct uprobe *uprobe,
    +static int write_opcode(struct mm_struct *mm, struct arch_uprobe *auprobe,
    unsigned long vaddr, uprobe_opcode_t opcode)
    {
    struct page *old_page, *new_page;
    struct address_space *mapping;
    void *vaddr_old, *vaddr_new;
    struct vm_area_struct *vma;
    + struct uprobe *uprobe;
    loff_t addr;
    int ret;

    @@ -216,6 +229,7 @@ static int write_opcode(struct mm_struct *mm, struct uprobe *uprobe,
    if (!valid_vma(vma, is_bkpt_insn(&opcode)))
    goto put_out;

    + uprobe = container_of(auprobe, struct uprobe, arch);
    mapping = uprobe->inode->i_mapping;
    if (mapping != vma->vm_file->f_mapping)
    goto put_out;
    @@ -326,7 +340,7 @@ static int is_bkpt_at_addr(struct mm_struct *mm, unsigned long vaddr)
    * For mm @mm, store the breakpoint instruction at @vaddr.
    * Return 0 (success) or a negative errno.
    */
    -int __weak set_bkpt(struct mm_struct *mm, struct uprobe *uprobe, unsigned long vaddr)
    +int __weak set_bkpt(struct mm_struct *mm, struct arch_uprobe *auprobe, unsigned long vaddr)
    {
    int result;

    @@ -337,7 +351,7 @@ int __weak set_bkpt(struct mm_struct *mm, struct uprobe *uprobe, unsigned long v
    if (result)
    return result;

    - return write_opcode(mm, uprobe, vaddr, UPROBES_BKPT_INSN);
    + return write_opcode(mm, auprobe, vaddr, UPROBES_BKPT_INSN);
    }

    /**
    @@ -351,7 +365,7 @@ int __weak set_bkpt(struct mm_struct *mm, struct uprobe *uprobe, unsigned long v
    * Return 0 (success) or a negative errno.
    */
    int __weak
    -set_orig_insn(struct mm_struct *mm, struct uprobe *uprobe, unsigned long vaddr, bool verify)
    +set_orig_insn(struct mm_struct *mm, struct arch_uprobe *auprobe, unsigned long vaddr, bool verify)
    {
    if (verify) {
    int result;
    @@ -363,7 +377,7 @@ set_orig_insn(struct mm_struct *mm, struct uprobe *uprobe, unsigned long vaddr,
    if (result != 1)
    return result;
    }
    - return write_opcode(mm, uprobe, vaddr, *(uprobe_opcode_t *)uprobe->insn);
    + return write_opcode(mm, auprobe, vaddr, *(uprobe_opcode_t *)auprobe->insn);
    }

    static int match_uprobe(struct uprobe *l, struct uprobe *r)
    @@ -593,13 +607,13 @@ static int copy_insn(struct uprobe *uprobe, struct vm_area_struct *vma, unsigned

    /* Instruction at the page-boundary; copy bytes in second page */
    if (nbytes < bytes) {
    - if (__copy_insn(mapping, vma, uprobe->insn + nbytes,
    + if (__copy_insn(mapping, vma, uprobe->arch.insn + nbytes,
    bytes - nbytes, uprobe->offset + nbytes))
    return -ENOMEM;

    bytes = nbytes;
    }
    - return __copy_insn(mapping, vma, uprobe->insn, bytes, uprobe->offset);
    + return __copy_insn(mapping, vma, uprobe->arch.insn, bytes, uprobe->offset);
    }

    static int install_breakpoint(struct mm_struct *mm, struct uprobe *uprobe,
    @@ -625,23 +639,23 @@ static int install_breakpoint(struct mm_struct *mm, struct uprobe *uprobe,
    if (ret)
    return ret;

    - if (is_bkpt_insn((uprobe_opcode_t *)uprobe->insn))
    + if (is_bkpt_insn((uprobe_opcode_t *)uprobe->arch.insn))
    return -EEXIST;

    - ret = arch_uprobes_analyze_insn(mm, uprobe);
    + ret = arch_uprobes_analyze_insn(mm, &uprobe->arch);
    if (ret)
    return ret;

    uprobe->flags |= UPROBES_COPY_INSN;
    }
    - ret = set_bkpt(mm, uprobe, addr);
    + ret = set_bkpt(mm, &uprobe->arch, addr);

    return ret;
    }

    static void remove_breakpoint(struct mm_struct *mm, struct uprobe *uprobe, loff_t vaddr)
    {
    - set_orig_insn(mm, uprobe, (unsigned long)vaddr, true);
    + set_orig_insn(mm, &uprobe->arch, (unsigned long)vaddr, true);
    }

    static void delete_uprobe(struct uprobe *uprobe)



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