Messages in this thread | | | Date | Tue, 19 Sep 2017 11:05:38 +0900 | From | Sergey Senozhatsky <> | Subject | Re: [PATCH 0/5] [RFC] printk/ia64/ppc64/parisc64: let's deprecate %pF/%pf printk specifiers |
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On (09/18/17 20:39), Helge Deller wrote: [..] > > A few new warnings when building on ia64: > > > > arch/ia64/kernel/module.c:931: warning: passing argument 1 of 'dereference_function_descriptor' makes pointer from integer without a cast > > arch/ia64/kernel/module.c:931: warning: return makes integer from pointer without a cast > > kernel/kallsyms.c:325: warning: assignment makes integer from pointer without a cast > > kernel/kallsyms.c:325: warning: passing argument 1 of 'dereference_kernel_function_descriptor' makes pointer from integer without a cast > > > I got similiar warnings on parisc. > This patch on top of yours fixed those: >
Tony, Helge,
thanks for the reports!
I'll simply convert everything to `unsigned long'. including the dereference_function_descriptor() function [I believe there are still some casts happening when we pass addr from kernel/module dereference functions to dereference_function_descriptor(), or when we return `void *' back to symbol resolution code, etc.) besides, it seems that everything that uses dereference_function_descriptor() wants `unsigned long' anyway:
drivers/misc/kgdbts.c: addr = (unsigned long) dereference_function_descriptor((void *)addr); init/main.c: addr = (unsigned long) dereference_function_descriptor(fn); kernel/extable.c: addr = (unsigned long) dereference_function_descriptor(ptr); kernel/module.c: unsigned long a = (unsigned long)dereference_function_descriptor(addr);
so I'll just switch it to ulong.
> I did tried your testcases too. > > "echo 1 > /proc/sys/vm/drop_caches" gave correct output: > printk#1 schedule_timeout+0x0/0x4a8 > printk#2 schedule_timeout+0x0/0x4a8 > printk#3 proc_sys_call_handler+0x120/0x180 > printk#4 proc_sys_call_handler+0x120/0x180 > printk#5 proc_sys_call_handler+0x120/0x180 > printk#6 proc_sys_call_handler+0x120/0x180 > > and here is "modprobe zram": > printk#7 __UNIQUE_ID_vermagic8+0xb9a4/0xbd04 [zram] > printk#8 __UNIQUE_ID_vermagic8+0xb9a4/0xbd04 [zram] > printk#9 do_one_initcall+0x194/0x290 > printk#10 do_one_initcall+0x194/0x290 > printk#11 do_one_initcall+0x194/0x290 > printk#12 do_one_initcall+0x194/0x290 > printk#13 zram_init+0x22c/0x2a0 [zram] > printk#14 zram_init+0x22c/0x2a0 [zram] > printk#15 zram_init+0x22c/0x2a0 [zram] > printk#16 zram_init+0x22c/0x2a0 [zram] > > I wonder why printk#7 and printk#8 don't show "zram_init"...
interesting... what does the unpatched kernel show?
> Regarding your patches: > > In arch/parisc/kernel/process.c: > +void *dereference_kernel_function_descriptor(void *ptr) > +{ > + if (ptr < (void *)__start_opd || (void *)__end_opd < ptr) > > This needs to be (__end_opd is outside): > + if (ptr < (void *)__start_opd || (void *)__end_opd <= ptr) > > The same is true for the checks in the other arches.
um... yeah. __end_opd is definitely not a valid place for a descriptor! I think I had `if (!(ptr >= __start_opd && ptr < __end_opd))' which I wrongly converted. "shame, shame, shame".
thanks!
> I'd suggest to move the various > extern char __start_opd[], __end_opd[]; > out of arch/<arch>/include/asm/sections.h and into <asm-generic/sections.h>
ok, will take a look.
-ss
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