Alexandr Andreev wrote:
> Hi, list.
> I have three little questions with linux-2.4.18 on my machine.
>
> My configuration is:
> MIPS R3000, linux-2.4.18 kernel from CVS,
> egcs-mips-linux-1.1.2-4 (egcs-2.91.66) and binutils-mips-linux-2.8.1-2
>
> 1. When i use MIPS specific arch_get_unmapped_area() function, my kernel
> hangs. It looks like this:
> ...
> Freeing unused kernel memory: 108k freed
> do_page_fault() #2: sending SIGSEGV to init for illegal read access
> from 0fb65330 (epc == 0fb65330, ra == 0fb851dc)
> ... and so on. Last message is printed infinitely.
>
> So, i have to give up HAVE_ARCH_UNMAPPED_AREA feature, and to use
> common arch_get_unmapped_area() routine.
>
I took a look of the arch_get_unmapped_area(), and it looks fine to me.
Can you try the following changes and let me know what happens?
1) change COLOUR_ALIGN
#define COLOUR_ALIGN(addr,pgoff) addr
2) I don't understand why we need color alignment if file is not NULL. (Can
someone explain?). So you can try to remove that condition:
diff -Nru ./arch/mips/kernel/syscall.c.orig ./arch/mips/kernel/syscall.c
--- ./arch/mips/kernel/syscall.c.orig Sat May 11 00:05:34 2002
+++ ./arch/mips/kernel/syscall.c Fri May 24 13:54:47 2002
@@ -77,7 +77,7 @@
if (len > TASK_SIZE)
return -ENOMEM;
do_color_align = 0;
- if (filp || (flags & MAP_SHARED))
+ if (flags & MAP_SHARED)
do_color_align = 1;
if (addr) {
if (do_color_align)
> 2. There is a strange code in the local_flush_tlb_page() function
> (tlb-r3k.c and tlb-r4k.c):
> ...
> if (!vma || vma->vm_mm->context != 0) {
> unsigned long flags;
> int oldpid, newpid, idx;
> #ifdef DEBUG_TLB
> printk("[tlbpage<%lu,0x%08lx>]", vma->vm_mm->context, page);
> #endif
> newpid = (vma->vm_mm->context & 0xfc0);
> ^^^^^
> Hmm... the kernel will crash if vma ==0. I guess that this code must look
> like this:
>
> if (vma && vma->vm_mm->context !=0) {
>
> Is any patches required?
>
I think you just found a bug. The fix looks good to me.
> 3. I have some problems, when i try to compile latest kernels with my egcs
> and binutils, such as problems with "__INIT" and "__FINI" assembler
> macroses:
>
> # mips-linux-gcc -D__ASSEMBLY__ -D__KERNEL__ -I include -G 0
> -mno-abicalls -fno-pic -mcpu=r3000 -mips1 -pipe -c entry.S -o entry.o
> entry.S: Assembler messages:
> entry.S:179: Error: .previous without corresponding .section; ignored
>
> ... and ".macro" assembler command usage:
>
> # mips-linux-gcc -D__ASSEMBLY__ -D__KERNEL__ -I include -G 0
> -mno-abicalls -fno-pic -mcpu=r3000 -mips1 -pipe -c head.S -o head.o
> head.S: Assembler messages:
> head.S:224: Error: .size expression too complicated to fix up
> head.S:224: Error: .size expression too complicated to fix up
> head.S:224: Error: .size expression too complicated to fix up
> head.S:224: Error: .size expression too complicated to fix up
> make[1]: *** [head.o] Error 1
>
> I know that my binutils are obsolete and so, I tried to use some newer
> binutils (2.9.5-1, 2.9.5-3), but my kernel crashed :(. Please, can you
> answer
> me, what egcs & binutils are suitable for linux-2.4.18 and MIPS R3000
> compliant?
>
We have been using gcc 2.9.5 and binutils 2.10.x for R3000 CPUs for quite a
while with no problems. It seems newer gcc and binutiles are fine too.
Jun
