Date: Mon, 29 Jun 2015 18:13:57 +0800 From: Julian Elischer <julian@freebsd.org> To: Konstantin Belousov <kostikbel@gmail.com> Cc: "hackers@freebsd.org" <hackers@freebsd.org>, freebsd-current <freebsd-current@freebsd.org> Subject: Re: libc compile failure with new syscall. Message-ID: <55911A65.9090600@freebsd.org> In-Reply-To: <20150629084316.GS2080@kib.kiev.ua> References: <559102DB.4050902@freebsd.org> <20150629084316.GS2080@kib.kiev.ua>
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On 6/29/15 4:43 PM, Konstantin Belousov wrote:
> On Mon, Jun 29, 2015 at 04:33:31PM +0800, Julian Elischer wrote:
>> Hi all,
>>
>> At $JOB we have a few extra syscalls that we have added to our kernel.
>>
>> After generating the new sysent files in /sys/kern, libc fails to
>> compile with:
>>
>> ===> lib/libc (obj,depend,all,install)
>> building shared library libc.so.7
>> [...]
>> /usr/bin/ld: rlk_check_offline.So: relocation R_X86_64_32 against
>> `SYS_rlk_check_offline' can not be used when making a shared object;
>> recompile with -fPIC
>> rlk_check_offline.So: could not read symbols: Bad value
>> *** [libc.so.7] Error code 1
>>
>> this suggests that the code that generates the libc syscall stubs is
>> generating something the linker doesn't like.
> No, this suggests that the symbol SYS_rlk_check_offline was undefined
> when assembling your rlk_check_offline.S.
>
> Check the way you generated the stuff from syscalls.master. Most likely,
> sys/sys/syscall.h update was lost.
/sys/sys/syscall.h:
#define SYS_pz_openat_ex 587
#define SYS_rlk_check_offline 588 <----
#define SYS_MAXSYSCALL 589
as shown below..
>
>>
>> the definition of the syscall is:
>>
>> 588 AUE_NULL NOSTD { int rlk_check_offline(char *localfs,
>> char *path, \
>> int *is_offline, int rlk_flags, \
>> int *cache_status); }
>> ------
>> which generates (in various files):
>> { AS(rlk_check_offline_args), (sy_call_t *)lkmressys,
>> AUE_NULL, NULL, 0, 0, 0, SY_THR_ABSENT }, /* 588 = rlk_check_offline */
>> ------
>> "rlk_check_offline", /* 588 =
>> rlk_check_offline */
>> ------
>> /* rlk_check_offline */
>> case 588: {
>> struct rlk_check_offline_args *p = params;
>> uarg[0] = (intptr_t) p->localfs; /* char * */
>> uarg[1] = (intptr_t) p->path; /* char * */
>> uarg[2] = (intptr_t) p->is_offline; /* int * */
>> iarg[3] = p->rlk_flags; /* int */
>> uarg[4] = (intptr_t) p->cache_status; /* int * */
>> *n_args = 5;
>> break;
>> }
>> -------
>> #define SYS_rlk_check_offline 588
> ^^^^^ This must be seen by asm.
>
> Note that in the stock sources, lib/libc/amd64/SYS.h includes syscall.h.
and it does here too..
otherwise all the other syscalls would fail.... hmmm wonder if I need
to install the new one into /usr/include/sys/first.
ah that's it I'm doing "make libraries" and it requires the new
syscall.h to be in /usr/include.
thanks for that.. now for the next problem...
>
>> -------
>> struct rlk_check_offline_args {
>> char localfs_l_[PADL_(char *)]; char * localfs; char
>> localfs_r_[PADR_(char *)];
>> char path_l_[PADL_(char *)]; char * path; char
>> path_r_[PADR_(char *)];
>> char is_offline_l_[PADL_(int *)]; int * is_offline; char
>> is_offline_r_[PADR_(int *)];
>> char rlk_flags_l_[PADL_(int)]; int rlk_flags; char
>> rlk_flags_r_[PADR_(int)];
>> char cache_status_l_[PADL_(int *)]; int * cache_status; char
>> cache_status_r_[PADR_(int *)];
>> };
>> int sys_rlk_check_offline(struct thread *, struct
>> rlk_check_offline_args *);
>> #define SYS_AUE_rlk_check_offline AUE_NULL
>>
>> -------
>>
>>
>>
>> the generated stub looks like:
>> $ cat /usr/obj/usr/src/lib/libc/rlk_check_offline.S
>>
>> #include "compat.h"
>> #include "SYS.h"
>> RSYSCALL(rlk_check_offline)
>> .section .note.GNU-stack,"",%progbits
>>
>> --------
>>
>>
>> nothing in this definition looks special, So I'm surprised that the
>> libc build doesn't like it.
>> This is a (just) post 10.1 10-stable. But we plan to move to 11 soon too.
>>
>> Any suggestions as to what I should change would be greatly
>> appreciated.. I'm running out of ideas.
>>
>>
>>
>>
>>
>>
>>
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>
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