From: Andrew Morton <akpm@digeo.com>
To: Roland McGrath <roland@redhat.com>
Cc: torvalds@transmeta.com, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] i386 uaccess to fixmap pages
Date: Thu, 8 May 2003 21:31:19 -0700 [thread overview]
Message-ID: <20030508213119.58dd490d.akpm@digeo.com> (raw)
In-Reply-To: <200305090203.h4923CM11039@magilla.sf.frob.com>
Roland McGrath <roland@redhat.com> wrote:
>
> This patch against 2.5.69 makes uaccess (i.e., access_ok and get/put_user)
> to user-accessible fixmap addresses on x86 work.
This doesn't apply against Linus's current tree.
> -#define access_ok(type,addr,size) (__range_ok(addr,size) == 0)
> +#define access_ok(type,addr,size) (__range_ok(addr,size) == 0 || \
> + __fixmap_access_ok((unsigned long)(addr), \
> + (size), (type)))
Your patch increases the kernel text by nearly 1%. That's rather a lot for
what is a fairly esoteric feature.
text data bss dec hex filename
2805911 592912 732516 4131339 3f0a0b /tmp/vmlinux
2825167 592982 732516 4150665 3f5589 vmlinux
Would it be possible to avoid this by just taking the fault and fixing
things up in the exception handler?
> #else
>
> -#define access_ok(type,addr,size) ( (__range_ok(addr,size) == 0) && \
> +#define access_ok(type,addr,size) ((__range_ok(addr,size) == 0) ? \
> ((type) == VERIFY_READ || boot_cpu_data.wp_works_ok || \
> - __verify_write((void *)(addr),(size))))
> + __verify_write((void *)(addr),(size))) : \
> + __fixmap_access_ok((unsigned long)(addr),size,type))
You'll be wanting to parenthesise `size' and `type' here.
For some reason the patch causes gcc-2.95.3 to choke over the
__put_user(d_off, &lastdirent->d_off);
statement in sys_getdents64().
fs/readdir.c: In function `sys_getdents64':
fs/readdir.c:285: internal error--unrecognizable insn:
(insn 138 212 147 (set (reg:SI 3 %ebx)
(asm_operands/v ("1: movl %%eax,0(%2)
2: movl %%edx,4(%2)
3:
.section .fixup,"ax"
4: movl %3,%0
jmp 3b
.previous
.section __ex_table,"a"
.align 4
.long 1b,4b
.long 2b,4b
.previous") ("=r") 0[
(reg:DI 1 %edx)
(reg:SI 0 %eax)
(const_int -14 [0xfffffff2])
(reg:SI 3 %ebx)
]
[
(asm_input:DI ("A"))
(asm_input:SI ("r"))
(asm_input:SI ("i"))
(asm_input:SI ("0"))
] ("fs/readdir.c") 277)) -1 (insn_list 112 (insn_list 119 (insn_list 137 (nil))))
(nil))
make[1]: *** [fs/readdir.o] Error 1
make[1]: *** Waiting for unfinished jobs....
make: *** [fs] Error 2
next prev parent reply other threads:[~2003-05-09 4:18 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2003-05-09 2:03 [PATCH] i386 uaccess to fixmap pages Roland McGrath
2003-05-09 4:31 ` Andrew Morton [this message]
2003-05-09 8:55 ` Roland McGrath
2003-05-09 9:19 ` Andrew Morton
2003-05-09 9:40 ` Roland McGrath
2003-05-09 10:43 ` Roland McGrath
2003-05-09 11:42 ` Dave Jones
2003-05-09 11:55 ` Alan Cox
2003-05-09 12:40 ` Jamie Lokier
2003-05-09 16:06 ` Linus Torvalds
2003-05-09 16:38 ` Dave Hansen
2003-05-09 15:55 ` Martin J. Bligh
2003-05-09 18:20 ` William Lee Irwin III
2003-05-09 16:48 ` Linus Torvalds
2003-05-09 17:16 ` Dave Hansen
2003-05-10 3:26 ` H. Peter Anvin
2003-05-10 15:31 ` Jamie Lokier
2003-05-10 17:23 ` Ulrich Drepper
2003-05-10 19:23 ` H. Peter Anvin
2003-05-10 20:52 ` Jamie Lokier
2003-05-09 17:28 Chuck Ebbert
2003-05-09 17:49 ` Linus Torvalds
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20030508213119.58dd490d.akpm@digeo.com \
--to=akpm@digeo.com \
--cc=linux-kernel@vger.kernel.org \
--cc=roland@redhat.com \
--cc=torvalds@transmeta.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).