Re: [PATCH 2/2] Add LoongArch64 basic support

[Jinyang He]

On 2024-07-15 20:11, Camm Maguire wrote:

> =============================================================================
> 0890adf6cf6aabd719c32f99c962356126919a14
> Author:     Camm Maguire<camm@transcendence.maguirefamily.org>
> AuthorDate: Sun Jul 14 15:26:59 2024 -0400
> Commit:     Camm Maguire<camm@transcendence.maguirefamily.org>
> CommitDate: Sun Jul 14 15:26:59 2024 -0400
>
> Parent:     0fc02b307 debian version 2.7.0-23
> Contained:  Version_2_7_0pre master
> Follows:    Version_2_7_0pre26 (1)
>
> Link libboot.so into pre_ images with ld  to fix address, not dlopen
>
> 3 files changed, 10 insertions(+), 4 deletions(-)
> gcl/makefile            | 4 ++--
> gcl/unixport/makefile   | 4 ++--
> gcl/unixport/sys_init.c | 6 ++++++
>
> modified   gcl/makefile
> @@ -96,11 +96,11 @@ $(PORTDIR)/saved_pre_gcl: $(HDIR)cmpinclude.h
>         (cd $(ODIR); $(MAKE) all)
>         $(MAKE) $<
>         rm -f o/cmpinclude.h ; cp h/cmpinclude.h o
> -       cd $(@D) && $(MAKE) $(@F)
> +       cd $(@D) && LD_LIBRARY_PATH=$(@D):$$LD_LIBRARY_PATH $(MAKE) $(@F)
>         touch $< $@
>   
>   $(PORTDIR)/saved_gcl0: $(PORTDIR)/saved_pre_gcl $(HDIR)cmpinclude.h
> -       cd $(@D) && echo '(time (load "boot.lisp"))' | ../$<
> +       cd $(@D) && echo '(time (load "boot.lisp"))' | 
> LD_LIBRARY_PATH=$(@D):$$LD_LIBRARY_PATH ../$<
>         cd $(@D) && $(MAKE) saved_gcl && mv saved_gcl $(@F)
>   
>   $(PORTDIR)/saved_gcl1: $(PORTDIR)/saved_gcl0 $(HDIR)cmpinclude.h
> modified   gcl/unixport/makefile
> @@ -155,9 +155,9 @@ ifeq ($(GNU_LD),1)
>         $(CC) $(LD_FLAGS) -o raw_$*$(EXE) $(filter %.o,$^) \
>                 $(shell if echo $@ | grep -q gprof ; then echo "-pg"; else echo 
> ""; fi) \
>                 -rdynamic -L. $(EXTRA_LD_LIBS) $(LD_STACK_FLAGS) \
> -               -Wl,-Map raw_$*_map $(LD_LIBS_PRE) -l$* $(LD_LIBS_POST)
> +               -Wl,-Map raw_$*_map $(LD_LIBS_PRE) -l$* $(LD_LIBS_POST) -lboot
>   else
> -       $(CC) $(LD_FLAGS) -o raw_$*$(EXE) $(filter %.o,$^) $(shell if grep -q gprof $@ ; then echo 
> "-pg"; else echo ""; fi) -L. $(EXTRA_LD_LIBS) $(LD_LIBS_PRE) -l$* 
> $(LD_LIBS_POST)
> +       $(CC) $(LD_FLAGS) -o raw_$*$(EXE) $(filter %.o,$^) $(shell if grep -q gprof $@ ; then echo 
> "-pg"; else echo ""; fi) -L. $(EXTRA_LD_LIBS) $(LD_LIBS_PRE) -l$* 
> $(LD_LIBS_POST) -lboot
>   endif
>   
>   map_%:
> modified   gcl/unixport/sys_init.c
> @@ -20,6 +20,12 @@ gcl_init_init()
>   #endif
>     }
>   #endif
> +
> +#if defined(pre_gcl)
> +  gcl_init_boot();/*Superfluous call to hard link boot.so into pre
> +                   image only, where it is used in raw_ and saved_
> +                   images and must have a fixed address*/
> +#endif
>     
>     lsp_init("lsp","gcl_export");
> =============================================================================
It doesn't mmap to same.. The strace shows,
for raw_pre_gcl,
[...] Map libboot.so to memroy (, from dynamic linker ld.so.1)
openat(AT_FDCWD, "libboot.so", O_RDONLY|O_CLOEXEC) = 3
read(3, ...
statx(3, ...
mmap(NULL, 120864, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) 
= 0x7ffff01b0000
mmap(0x7ffff01c4000, 32768, PROT_READ|PROT_WRITE, 
MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x10000) = 0x7ffff01c4000
mmap(0x7ffff01cc000, 6176, PROT_READ|PROT_WRITE, 
MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x7ffff01cc000
close(3)
[...] Set rlimit_stack in gcl_init_alloc as gcl_alloc_initialized == 0
prlimit64(0, RLIMIT_STACK, {rlim_cur=RLIM64_INFINITY, 
rlim_max=RLIM64_INFINITY}, NULL) = 0
[...] Set no_randomize and re-exec
personality(PER_LINUX|ADDR_NO_RANDOMIZE) = 0x400000 
(PER_LINUX|READ_IMPLIES_EXEC)
personality(0xffffffff)                 = 0x40000 
(PER_LINUX|ADDR_NO_RANDOMIZE)
brk(0x56ead0d5f)                        = 0x56ead0d5f
execve("raw_pre_gcl", ...
brk(NULL)
[...] Map libboot.so to memroy after re-exec
openat(AT_FDCWD, "libboot.so", O_RDONLY|O_CLOEXEC) = 3
read(3, ...
statx(3, ...
mmap(NULL, 120864, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) 
= 0x2aaaab114000
mmap(0x2aaaab128000, 32768, PROT_READ|PROT_WRITE, 
MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x10000) = 0x2aaaab128000
mmap(0x2aaaab130000, 6176, PROT_READ|PROT_WRITE, 
MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x2aaaab130000
close(3)
[...] Then we can see it maps to another position. 0x2aaaab114000 vs 
0x7ffff01b0000

for saved_pre_gcl,
[...] Map libboot.so to memroy
openat(AT_FDCWD, "libboot.so", O_RDONLY|O_CLOEXEC) = 3
read(3, ...
statx(3, ...
mmap(NULL, 120864, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) 
= 0x7ffff2a68000
mmap(0x7ffff2a7c000, 32768, PROT_READ|PROT_WRITE, 
MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x10000) = 0x7ffff2a7c000
mmap(0x7ffff2a84000, 6176, PROT_READ|PROT_WRITE, 
MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x7ffff2a84000
close(3)
[...] Because "gcl_alloc_initialized == 1", so it didn't call 
gcl_init_alloc before. Re-exec.
personality(PER_LINUX|READ_IMPLIES_EXEC) = 0 (PER_LINUX)
personality(PER_LINUX|ADDR_NO_RANDOMIZE) = 0x400000 
(PER_LINUX|READ_IMPLIES_EXEC)
personality(0xffffffff)                 = 0x40000 
(PER_LINUX|ADDR_NO_RANDOMIZE)
brk(0x43930dd9)                         = 0x43930dd9
execve("saved_pre_gcl", ...
[...] Map libboot.so to memroy after re-exec
openat(AT_FDCWD, "libboot.so", O_RDONLY|O_CLOEXEC) = 3
read(3, ...
statx(3, ...
mmap(NULL, 120864, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) 
= 0x7ffff2a68000
mmap(0x7ffff2a7c000, 32768, PROT_READ|PROT_WRITE, 
MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x10000) = 0x7ffff2a7c000
mmap(0x7ffff2a84000, 6176, PROT_READ|PROT_WRITE, 
MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x7ffff2a84000
close(3)

So the patch didn't link libboot.so to fixed address becuase the
dynamic linker use mmap to map libboot.so, gcl_init_alloc also
influence the re-exec dynamic linker mmap range.


Thanks,
Jinyang