Re: [musl] Add PAGESIZE definition for LoongArch

[Rich Felker <dalias@libc.org>]

On Tue, May 07, 2024 at 09:30:13AM +0800, lixing wrote:
> 
> 在 2024/5/6 下午8:36, Rich Felker 写道:
> >On Mon, May 06, 2024 at 05:05:36PM +0800, lixing wrote:
> >>Hi, Rich,
> >>
> >>  arch/loongarch64/bits/limits.h | 1 +
> >>  1 file changed, 1 insertion(+)
> >>  create mode 100644 arch/loongarch64/bits/limits.h
> >>
> >>diff --git a/arch/loongarch64/bits/limits.h b/arch/loongarch64/bits/limits.h
> >>new file mode 100644
> >>index 00000000..5cd9aad6
> >>--- /dev/null
> >>+++ b/arch/loongarch64/bits/limits.h
> >>@@ -0,0 +1 @@
> >>+#define PAGESIZE 16384
> >Can you explain why you want this change? I would be very hesitant to
> >merge it. Defining PAGESIZE for an arch is a contract that the
> >application-facing runtime page size (i.e. mmap granularity) can
> >*never*, now or in the future, be anything other than the value you
> >define this macro as having.
> 
> when I debuging "indent" program error, the  caculation of
> relro_start and relro_end in function kernel_mapped_dso get wrong
> value. It seems the PAGE_SIZE value is 0 and it come from
> libc.page_size, but the libc.page_size initialized until __dls3. Is
> there any other way to make the PAGE_SIZE correct at the before
> __dls3 ?

I believe this is a known bug that somehow got skipped over in the
last release cycle. I'll get it fixed. It does not mean you need to
define a constant PAGESIZE.

> Also, if the xmalloc low and high address aparted by the  protect
> page in a  loop,  it seems to trigger SIGSEGV when the loop meet the
> protect page. Can this situation happen?

I don't understand.

Rich