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    SubjectRe: [PATCH v2 7/9] x86/module: Use text_poke() for late relocations
    On Fri, Apr 17, 2020 at 04:29:44PM +0200, Peter Zijlstra wrote:
    > On Fri, Apr 17, 2020 at 09:04:32AM -0500, Josh Poimboeuf wrote:
    > > +int apply_relocate_add(Elf64_Shdr *sechdrs,
    > > + const char *strtab,
    > > + unsigned int symindex,
    > > + unsigned int relsec,
    > > + struct module *me)
    > > +{
    > > + int ret;
    > > + bool early = me->state == MODULE_STATE_UNFORMED;
    > > + void *(*write)(void *, const void *, size_t) = memcpy;
    > > +
    > > + if (!early) {
    > > + write = text_poke;
    > > + mutex_lock(&text_mutex);
    > > + }
    > > +
    > > + ret = __apply_relocate_add(sechdrs, strtab, symindex, relsec, me,
    > > + write);
    > > +
    > > + if (!early) {
    > > + mutex_unlock(&text_mutex);
    > > + text_poke_sync();
    >
    > I'm thinking text_poke_sync() wants to be inside text_mutex. Although
    > given that nothing should be running that text, it really doesn't
    > matter.

    Yeah, makes sense.

    diff --git a/arch/x86/kernel/module.c b/arch/x86/kernel/module.c
    index 2a997afa04c6..23c95a53d20e 100644
    --- a/arch/x86/kernel/module.c
    +++ b/arch/x86/kernel/module.c
    @@ -237,8 +237,8 @@ int apply_relocate_add(Elf64_Shdr *sechdrs,
    write);

    if (!early) {
    - mutex_unlock(&text_mutex);
    text_poke_sync();
    + mutex_unlock(&text_mutex);
    }

    return ret;
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      Last update: 2020-04-17 16:52    [W:4.410 / U:0.008 seconds]
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