lkml.org 
[lkml]   [2018]   [Apr]   [20]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Date
    Subject[REVIEW][PATCH 20/22] signal/um: Use force_sig_fault where appropriate
    Filling in struct siginfo before calling force_sig_info a tedious and
    error prone process, where once in a great while the wrong fields
    are filled out, and siginfo has been inconsistently cleared.

    Simplify this process by using the helper force_sig_fault. Which
    takes as a parameters all of the information it needs, ensures
    all of the fiddly bits of filling in struct siginfo are done properly
    and then calls force_sig_info.

    In short about a 5 line reduction in code for every time force_sig_info
    is called, which makes the calling function clearer.

    Cc: Jeff Dike <jdike@addtoit.com>
    Cc: Richard Weinberger <richard@nod.at>
    Cc: user-mode-linux-devel@lists.sourceforge.net
    Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
    ---
    arch/um/kernel/ptrace.c | 13 +++----------
    arch/um/kernel/trap.c | 26 ++++++++------------------
    2 files changed, 11 insertions(+), 28 deletions(-)

    diff --git a/arch/um/kernel/ptrace.c b/arch/um/kernel/ptrace.c
    index bc2a516c190f..1a1d88a4d940 100644
    --- a/arch/um/kernel/ptrace.c
    +++ b/arch/um/kernel/ptrace.c
    @@ -115,17 +115,10 @@ long arch_ptrace(struct task_struct *child, long request,
    static void send_sigtrap(struct task_struct *tsk, struct uml_pt_regs *regs,
    int error_code)
    {
    - struct siginfo info;
    -
    - memset(&info, 0, sizeof(info));
    - info.si_signo = SIGTRAP;
    - info.si_code = TRAP_BRKPT;
    -
    - /* User-mode eip? */
    - info.si_addr = UPT_IS_USER(regs) ? (void __user *) UPT_IP(regs) : NULL;
    -
    /* Send us the fake SIGTRAP */
    - force_sig_info(SIGTRAP, &info, tsk);
    + force_sig_fault(SIGTRAP, TRAP_BRKPT,
    + /* User-mode eip? */
    + UPT_IS_USER(regs) ? (void __user *) UPT_IP(regs) : NULL, tsk);
    }

    /*
    diff --git a/arch/um/kernel/trap.c b/arch/um/kernel/trap.c
    index 5f0ff17cd790..48b70dcb6963 100644
    --- a/arch/um/kernel/trap.c
    +++ b/arch/um/kernel/trap.c
    @@ -162,14 +162,9 @@ static void show_segv_info(struct uml_pt_regs *regs)

    static void bad_segv(struct faultinfo fi, unsigned long ip)
    {
    - struct siginfo si;
    -
    - clear_siginfo(&si);
    - si.si_signo = SIGSEGV;
    - si.si_code = SEGV_ACCERR;
    - si.si_addr = (void __user *) FAULT_ADDRESS(fi);
    current->thread.arch.faultinfo = fi;
    - force_sig_info(SIGSEGV, &si, current);
    + force_sig_fault(SIGSEGV, SEGV_ACCERR, (void __user *) FAULT_ADDRESS(fi),
    + current);
    }

    void fatal_sigsegv(void)
    @@ -215,13 +210,12 @@ void segv_handler(int sig, struct siginfo *unused_si, struct uml_pt_regs *regs)
    unsigned long segv(struct faultinfo fi, unsigned long ip, int is_user,
    struct uml_pt_regs *regs)
    {
    - struct siginfo si;
    jmp_buf *catcher;
    + int si_code;
    int err;
    int is_write = FAULT_WRITE(fi);
    unsigned long address = FAULT_ADDRESS(fi);

    - clear_siginfo(&si);
    if (!is_user && regs)
    current->thread.segv_regs = container_of(regs, struct pt_regs, regs);

    @@ -241,7 +235,7 @@ unsigned long segv(struct faultinfo fi, unsigned long ip, int is_user,

    if (SEGV_IS_FIXABLE(&fi))
    err = handle_page_fault(address, ip, is_write, is_user,
    - &si.si_code);
    + &si_code);
    else {
    err = -EFAULT;
    /*
    @@ -273,18 +267,14 @@ unsigned long segv(struct faultinfo fi, unsigned long ip, int is_user,
    show_segv_info(regs);

    if (err == -EACCES) {
    - si.si_signo = SIGBUS;
    - si.si_errno = 0;
    - si.si_code = BUS_ADRERR;
    - si.si_addr = (void __user *)address;
    current->thread.arch.faultinfo = fi;
    - force_sig_info(SIGBUS, &si, current);
    + force_sig_fault(SIGBUS, BUS_ADRERR, (void __user *)address,
    + current);
    } else {
    BUG_ON(err != -EFAULT);
    - si.si_signo = SIGSEGV;
    - si.si_addr = (void __user *) address;
    current->thread.arch.faultinfo = fi;
    - force_sig_info(SIGSEGV, &si, current);
    + force_sig_fault(SIGSEGV, si_code, (void __user *) address,
    + current);
    }

    out:
    --
    2.14.1
    \
     
     \ /
      Last update: 2018-04-20 16:50    [W:4.008 / U:0.052 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site