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    SubjectRe: module tool with 2.6.9 limitation issue
    yiding_wang@agilent.com wrote:
    > I am using moudle-init-tools-3.1-pre6 with kernel 2.6.9. The new insmod seems have restrictions which failed using parameters to load a driver module.
    >
    > My module parameter is in the form of modname="*************** ****", a quite long one.
    > Run - insmod modname.o modname="*********** *******" (with a script), it complains about the space and treats the string next to the space to be a "Unknown parameter".
    >
    > By replacing the space with any character, then it complains
    > "modname: string parameter too long"

    Patch for that one is attached. It might be overkill,
    but it works with this patch (as long as parameter value length
    is <= 1024 -- not that I tried one of that length).

    Rusty or anyone else, where do the quotes come from?
    Here's what I enter:
    insmod test_module modprm="this test"

    but the kernel sees this parameter string:
    "modprm=this test"
    (with the quotation marks).
    Who/what moved the quotation marks? Is bash doing any of that?
    I don't see it in insmod or modprobe (with a quick look).

    > Reducing the length of the parameter to less than 1k character works fine.

    Right, parameter value length cannot be > 1024.

    > Same long parameter string wit space in between works fine under 2.4.25 with original insmod.
    >
    > Questions:
    > 1, Is this a bug or new insmod has restrictions?

    The limit is actually in linux/kernel/params.c, not in insmod.
    It seems a little arbitrary, but a parameter that long also seems
    quite excessive. Just break it into multiple parameters.

    > 2, If it is restriction on special character such as space, or limitation on parameter length, then why and what is the limit?

    Just 1024 bytes in total length.

    > 3, If insmod has limitation, then what is better way to pass long parameter with some special character?

    Just break it into multiple parameters....

    --
    ~Randy
    linux-2610-rc1-bk21
    description

    Signed-off-by: Randy Dunlap <rddunlap@osdl.org>

    diffstat:=
    kernel/params.c | 15 ++++++++++++---
    1 files changed, 12 insertions(+), 3 deletions(-)

    diff -Naurp ./kernel/params.c~modprm_quoted ./kernel/params.c
    --- ./kernel/params.c~modprm_quoted 2004-11-11 15:13:26.000000000 -0800
    +++ ./kernel/params.c 2004-11-11 19:42:36.714124784 -0800
    @@ -77,10 +77,16 @@ static int parse_one(char *param,
    static char *next_arg(char *args, char **param, char **val)
    {
    unsigned int i, equals = 0;
    - int in_quote = 0;
    + int in_quote = 0, quoted = 0;
    + char *next;

    /* Chew any extra spaces */
    while (*args == ' ') args++;
    + if (*args == '"') {
    + args++;
    + in_quote = 1;
    + quoted = 1;
    + }

    for (i = 0; args[i]; i++) {
    if (args[i] == ' ' && !in_quote)
    @@ -106,13 +112,16 @@ static char *next_arg(char *args, char *
    if (args[i-1] == '"')
    args[i-1] = '\0';
    }
    + if (quoted && args[i-1] == '"')
    + args[i-1] = '\0';
    }

    if (args[i]) {
    args[i] = '\0';
    - return args + i + 1;
    + next = args + i + 1;
    } else
    - return args + i;
    + next = args + i;
    + return next;
    }

    /* Args looks like "foo=bar,bar2 baz=fuz wiz". */
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      Last update: 2005-03-22 14:07    [W:0.044 / U:0.800 seconds]
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