Messages in this thread | | | Date | Thu, 15 Jul 2010 14:35:25 -0700 | From | Randy Dunlap <> | Subject | Re: Make CONFIG_DEBUG_RODATA boot-time configurable |
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On Thu, 15 Jul 2010 17:09:44 -0400 Dave Jones wrote:
> We had a request to disable DEBUG_RODATA in our kernel for debugging purposes. > Turning it off completely seems a bit unfortunate for the minority case > of people wanting to do debugging, so I came up with this patch to make > it a boot-time 'disable_rodata' argument. > > Signed-off-by: Dave Jones <davej@redhat.com> > > > diff --git a/init/main.c b/init/main.c > index a42fdf4..eb60fae 100644 > --- a/init/main.c > +++ b/init/main.c > @@ -820,6 +820,15 @@ static void run_init_process(char *init_filename) > kernel_execve(init_filename, argv_init, envp_init); > } > > +static unsigned int disable_rodata; > +static int __init set_disable_rodata(char *str) > +{ > + disable_rodata = 1; > + return 1; > +} > +__setup("disable_rodata", set_disable_rodata); > + > + > /* This is a non __init function. Force it to be noinline otherwise gcc > * makes it inline to init() and it becomes part of init.text section > */ > @@ -830,7 +839,8 @@ static noinline int init_post(void) > async_synchronize_full(); > free_initmem(); > unlock_kernel(); > - mark_rodata_ro(); > + if (disable_rodata == 0) > + mark_rodata_ro(); > system_state = SYSTEM_RUNNING; > numa_default_policy(); > diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt > index 4ddb58d..1320d80 100644 > --- a/Documentation/kernel-parameters.txt > +++ b/Documentation/kernel-parameters.txt > @@ -651,6 +651,10 @@ and is between 256 and 4096 characters. It is defined in the file > MTRR settings. This parameter disables that behavior, > possibly causing your machine to run very slowly. > > + disable_rodata [X86]
What is X86-specific about this boot option?
> + Don't mark .rodata section as read-only. > + May be useful for debugging. > + > disable_timer_pin_1 [X86] > Disable PIN 1 of APIC timer > Can be useful to work around chipset bugs. > --
--- ~Randy *** Remember to use Documentation/SubmitChecklist when testing your code ***
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