* Helge Deller <del...@gmx.de>: > On 19.09.2017 04:05, Sergey Senozhatsky wrote: > >On (09/18/17 20:39), Helge Deller wrote: > >>I did tried your testcases [on parisc] too. > ... > >>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? > > Really strange. > The unpatched kernel shows __UNIQUE_ID_vermagic8+0xb9a4/0xbd04 too. > The symbol should be known, because later on in printk13 it shows correctly > zram_init. > I'll need to dig deeper into it, but at least the regression is not due > to your patch.
Sergey, I was wrong with this assumption. Your implementation of dereference_module_function_descriptor() in arch/parisc/kernel/module.c is faulty. mod->arch.fdesc_offset is relative to the base address of the module, so you need to add to mod->core_layout.base. Here is the relevant patch to fix this issue (against mainline). Additionally I compare against mod->arch.fdesc_count instead of mod->arch.fdesc_max. Can you please fold it into your patch [PATCH 4/5] parisc64: Add .opd based function descriptor dereference for the next round? Thanks, Helge Signed-off-by: Helge Deller <del...@gmx.de> diff --git a/arch/parisc/kernel/module.c b/arch/parisc/kernel/module.c index f1a7693..ae3e6c5 100644 --- a/arch/parisc/kernel/module.c +++ b/arch/parisc/kernel/module.c @@ -66,6 +66,7 @@ #include <asm/pgtable.h> #include <asm/unwind.h> +#include <asm/sections.h> #if 0 #define DEBUGP printk @@ -954,3 +955,19 @@ void module_arch_cleanup(struct module *mod) { deregister_unwind_table(mod); } + +#ifdef CONFIG_64BIT +unsigned long dereference_module_function_descriptor(struct module *mod, + unsigned long addr) +{ + unsigned long opd_start = (Elf64_Addr) mod->core_layout.base + + mod->arch.fdesc_offset; + unsigned long opd_end = opd_start + + mod->arch.fdesc_count * sizeof(Elf64_Fdesc); + + if (addr < opd_start || addr >= opd_end) + return addr; + + return (unsigned long) dereference_function_descriptor((void *) addr); +} +#endif