Re: [Valgrind-users] assert on aarch64: m_redir.c vgPlain_redir_add_ifunc_target Assertion 'old' failed (revival #327427?)

[Paul F. <pj...@wa...>]

On 14-12-24 04:11, John Reiser wrote:
>> I've tried to build the last release but have not resolved the place 
>> why it tries to link against the non-existing libc and how to fix that...
> 
> Here are some workarounds:
> 
> I'm trying to build valgrind (memcheck) for 32-bit programs on Android
> running under 64-bit TermUX on 64-bit Android 14.  A fully-static 32-
> bit program created under Linux on [old] RaspberryPi does run
> under TermUX on my Samsung A9-Lite tablet with 3MB RAM!  All building
> for valgrind was done on the tablet.
> 
> Starting with "git clone; ./aclocal; ./configure --prefix=...";
> then in just a few minutes "make -j4" reaches
> =====
> $ gcc ... `m_coredump/coredump-elf.c
> m_coredump/coredump-elf.c:152:4: error: typedef redefinition with 
> different types ('struct Elf32_Nhdr' vs 'struct elf32_note')
>    152 |    Elf32_Nhdr;
>        |    ^
> /data/data/com.termux/files/usr/include/linux/elf.h:380:3: note: 
> previous definition is here
>    380 | } Elf32_Nhdr;
>        |   ^
> m_coredump/coredump-elf.c:775:17: warning: variable 'name' set but not 
> used [-Wunused-but-set-variable]
>    775 |    const HChar* name;
>        |                 ^
> =====
> 
> My usr/include/elf.h from ndk-root version 27c does have a Elf32_Nhdr,
> so I patch with
> =====
> diff --git a/coregrind/m_coredump/coredump-elf.c b/coregrind/m_coredump/ 
> coredump-elf.c
> index a4632d9e2..aa58e6f48 100644
> --- a/coregrind/m_coredump/coredump-elf.c
> +++ b/coregrind/m_coredump/coredump-elf.c
> @@ -140,8 +140,8 @@ static void fill_phdr(ESZ(Phdr) *phdr, const 
> NSegment *seg, UInt off, Bool write
>      phdr->p_align = VKI_PAGE_SIZE;
>   }
> 
> -#if defined(VGPV_arm_linux_android) || defined(VGPV_x86_linux_android) \
> -    || defined(VGPV_mips32_linux_android)
> +#if 0 && ( defined(VGPV_arm_linux_android) || 
> defined(VGPV_x86_linux_android) \
> +    || defined(VGPV_mips32_linux_android))
>   /* Android's libc doesn't provide a definition for this.  Hence: */
>   typedef
>      struct {
> =====


If elf.h doesn't indicate that it has a Elf32_Nhdr then we could add a 
configure check for that. See 
https://bugs.kde.org/show_bug.cgi?id=339861. Do we need to keep 
backwards compatibility with the old systems that didn't have Elf32_Nhdr?

> Building proceeds until
> =====  (Note "-m32")
> $ gcc -m64 ... -static ... -m32 -o vgpreload_core-arm-linux.so \
>       vgpreload_core_arm_linux_so_preloaded.o
> ld.lld: error: unable to find library -lc
> =====
> which I workaround by running "gcc -v ...", to get the command line,
> then manually running the 'ld' without the "-lc".  So gcc adding
> "-lc" was not necessary?


What is the full text of the line for linking vgpreload_core-arm-linux.so?

I don't know where -lc is coming from, maybe implicitly with lld and it 
needs -nostdlib.

Also I don't see how both -m32 and -m64 get added. In this case it seems 
harmless as the later -m32 will be taken.


> More building until (in directory coregrind):
> =====   (Note no "-m32")
> $ gcc -m64 ... -static ... -o valgrind \
>       valgrind-launcher-linux.o valgrind-m_debuglog.o
> ld.lld: error: unable to find library -lc
> =====
> 
> Next "dpkg --search libc.a" shows a nice-looking
>     usr/opt/ndk-multilib/aarch64-linux-android/lib/libc.a
> and manually adding that appears to succeed:
> =====
> $ cd /data/data/com.termux/files/home/valgrind/coregrind
> $ ld -o valgrind  valgrind-launcher-linux.o valgrind-m_debuglog.o \
> 
> /data/data/com.termux/files/usr/opt/ndk-multilib/aarch64-linux-android/ 
> lib/libc.a
> $ readelf --all --wide valgrind >valgrind.readelfcd ..
>     # 5744 lines; 10 Program headers; 29 Sections
> # Header      Offset   VirtAddr  PhysAddr  Fsiz  Msiz Flg  Align
> #  TLS       0x069870  0x271870  0x271870     8     8   R  0x8
> =====
> 
> But a trial run fails:
> =====
> $ cd coregrind
> $ ./valgrind
> error: "./valgrind": executable's TLS segment is underaligned: \
> alignment is 8 (skew 0), needs to be at least 64 for ARM64 Bionic
> Aborted
> $ echo $?
> 134   ## error 6 (134 - 128) ENXIO
> $
> =====
> 
> So now it's time to get the linker script from "ld --verbose ...",
> then make TLS 64-byte aligned.   To be continued ...

Do the Google/Android folks have any Valgrind patches for these issues?

A+
Paul