[PATCH 1/2] binfmt_elf_fdpic: support 64-bit systems
Greg Ungerer
gerg at kernel.org
Tue Jul 11 04:53:19 PDT 2023
Hi Palmer,
On 11/7/23 09:18, Palmer Dabbelt wrote:
> On Thu, 20 Apr 2023 07:58:29 PDT (-0700), gerg at kernel.org wrote:
>> Hi Palmer,
>>
>> On 19/4/23 13:27, Palmer Dabbelt wrote:
>>> On Wed, 29 Mar 2023 06:48:55 PDT (-0700), gerg at kernel.org wrote:
>>>>
>>>> On 22/3/23 08:49, Palmer Dabbelt wrote:
>>>>> On Tue, 28 Feb 2023 05:51:25 PST (-0800), gerg at kernel.org wrote:
>>>>>> The binfmt_flat_fdpic code has a number of 32-bit specific data
>>>>>> structures associated with it. Extend it to be able to support and
>>>>>> be used on 64-bit systems as well.
>>>>>>
>>>>>> The new code defines a number of key 64-bit variants of the core
>>>>>> elf-fdpic data structures - along side the existing 32-bit sized ones.
>>>>>> A common set of generic named structures are defined to be either
>>>>>> the 32-bit or 64-bit ones as required at compile time. This is a
>>>>>> similar technique to that used in the ELF binfmt loader.
>>>>>>
>>>>>> For example:
>>>>>>
>>>>>> elf_fdpic_loadseg is either elf32_fdpic_loadseg or elf64_fdpic_loadseg
>>>>>> elf_fdpic_loadmap is either elf32_fdpic_loadmap or elf64_fdpic_loadmap
>>>>>>
>>>>>> the choice based on ELFCLASS32 or ELFCLASS64.
>>>>>>
>>>>>> Signed-off-by: Greg Ungerer <gerg at kernel.org>
>>>>>> ---
>>>>>> fs/binfmt_elf_fdpic.c | 38 +++++++++++++++++-----------------
>>>>>> include/linux/elf-fdpic.h | 14 ++++++++++++-
>>>>>> include/uapi/linux/elf-fdpic.h | 15 ++++++++++++++
>>>>>> 3 files changed, 47 insertions(+), 20 deletions(-)
>>>>>
>>>>> Adding some of the binfmt/fs folks, who weren't directly on the mail. It's looking like we're generally OK with this in RISC-V land, though there's still no userspace posted. I don't think there's any rush here and it might be prudent to wait for userspace to start going through a bit of a review, but figured I'd at least poke everyone to see if there's any thoughts.
>>>>>
>>>>> I'm fine either way, so
>>>>> Acked-by: Palmer Dabbelt <palmer at rivosinc.com>
>>>>>
>>>>> if that helps any. Also happy to take this through the RISC-V tree along with the other if that's easier, but again no rush.
>>>>
>>>> Just following up. I haven't seen any feedback on this - did I miss any?
>>>
>>> If you did then I did too. I'm not really sure what to do here: it looks fine to me, but it's not really my area so I'd prefer to have someone who understands this stuff a bit better chime in.
>>>
>>> It looks like some Arm patches recently went in through that tree, though, so maybe that's how things are supposed to go here?
>>
>> There doesn't seem to be anyone who is clearly the designated maintainer
>> for binfmt_elf_fdpic, or even just sheparding fixes for it. It mostly seems
>> to be tree-wide changes and cleanups that are getting done to it.
>>
>> So I have no idea... I have at least one fix inside binfmt_elf_fdpic.c for
>> ARM architecture that I am preparing now too, not sure how that is going to
>> go either.
>
> Looks like maybe nobody is taking these, then? Certainly nobody has chimed in.
Yes, its been complete silence
> There's been some minor conflicts over the past few months, do you mind sending a v2? If nobody says anything on that I'll just take it via the RISC-V tree.
Sounds like a good plan.
I will send out a v2 today.
Regards
Greg
>>>>>> diff --git a/fs/binfmt_elf_fdpic.c b/fs/binfmt_elf_fdpic.c
>>>>>> index a05eafcacfb27..2eea6dd429fd6 100644
>>>>>> --- a/fs/binfmt_elf_fdpic.c
>>>>>> +++ b/fs/binfmt_elf_fdpic.c
>>>>>> @@ -138,7 +138,7 @@ static int is_constdisp(struct elfhdr *hdr)
>>>>>> static int elf_fdpic_fetch_phdrs(struct elf_fdpic_params *params,
>>>>>> struct file *file)
>>>>>> {
>>>>>> - struct elf32_phdr *phdr;
>>>>>> + struct elf_phdr *phdr;
>>>>>> unsigned long size;
>>>>>> int retval, loop;
>>>>>> loff_t pos = params->hdr.e_phoff;
>>>>>> @@ -560,8 +560,8 @@ static int create_elf_fdpic_tables(struct linux_binprm *bprm,
>>>>>> sp &= ~7UL;
>>>>>>
>>>>>> /* stack the load map(s) */
>>>>>> - len = sizeof(struct elf32_fdpic_loadmap);
>>>>>> - len += sizeof(struct elf32_fdpic_loadseg) * exec_params->loadmap->nsegs;
>>>>>> + len = sizeof(struct elf_fdpic_loadmap);
>>>>>> + len += sizeof(struct elf_fdpic_loadseg) * exec_params->loadmap->nsegs;
>>>>>> sp = (sp - len) & ~7UL;
>>>>>> exec_params->map_addr = sp;
>>>>>>
>>>>>> @@ -571,8 +571,8 @@ static int create_elf_fdpic_tables(struct linux_binprm *bprm,
>>>>>> current->mm->context.exec_fdpic_loadmap = (unsigned long) sp;
>>>>>>
>>>>>> if (interp_params->loadmap) {
>>>>>> - len = sizeof(struct elf32_fdpic_loadmap);
>>>>>> - len += sizeof(struct elf32_fdpic_loadseg) *
>>>>>> + len = sizeof(struct elf_fdpic_loadmap);
>>>>>> + len += sizeof(struct elf_fdpic_loadseg) *
>>>>>> interp_params->loadmap->nsegs;
>>>>>> sp = (sp - len) & ~7UL;
>>>>>> interp_params->map_addr = sp;
>>>>>> @@ -740,12 +740,12 @@ static int elf_fdpic_map_file(struct elf_fdpic_params *params,
>>>>>> struct mm_struct *mm,
>>>>>> const char *what)
>>>>>> {
>>>>>> - struct elf32_fdpic_loadmap *loadmap;
>>>>>> + struct elf_fdpic_loadmap *loadmap;
>>>>>> #ifdef CONFIG_MMU
>>>>>> - struct elf32_fdpic_loadseg *mseg;
>>>>>> + struct elf_fdpic_loadseg *mseg;
>>>>>> #endif
>>>>>> - struct elf32_fdpic_loadseg *seg;
>>>>>> - struct elf32_phdr *phdr;
>>>>>> + struct elf_fdpic_loadseg *seg;
>>>>>> + struct elf_phdr *phdr;
>>>>>> unsigned long load_addr, stop;
>>>>>> unsigned nloads, tmp;
>>>>>> size_t size;
>>>>>> @@ -767,7 +767,7 @@ static int elf_fdpic_map_file(struct elf_fdpic_params *params,
>>>>>>
>>>>>> params->loadmap = loadmap;
>>>>>>
>>>>>> - loadmap->version = ELF32_FDPIC_LOADMAP_VERSION;
>>>>>> + loadmap->version = ELF_FDPIC_LOADMAP_VERSION;
>>>>>> loadmap->nsegs = nloads;
>>>>>>
>>>>>> load_addr = params->load_addr;
>>>>>> @@ -843,8 +843,8 @@ static int elf_fdpic_map_file(struct elf_fdpic_params *params,
>>>>>> if (phdr->p_vaddr >= seg->p_vaddr &&
>>>>>> phdr->p_vaddr + phdr->p_memsz <=
>>>>>> seg->p_vaddr + seg->p_memsz) {
>>>>>> - Elf32_Dyn __user *dyn;
>>>>>> - Elf32_Sword d_tag;
>>>>>> + Elf_Dyn __user *dyn;
>>>>>> + Elf_Sword d_tag;
>>>>>>
>>>>>> params->dynamic_addr =
>>>>>> (phdr->p_vaddr - seg->p_vaddr) +
>>>>>> @@ -854,11 +854,11 @@ static int elf_fdpic_map_file(struct elf_fdpic_params *params,
>>>>>> * one item, and that the last item is a NULL
>>>>>> * entry */
>>>>>> if (phdr->p_memsz == 0 ||
>>>>>> - phdr->p_memsz % sizeof(Elf32_Dyn) != 0)
>>>>>> + phdr->p_memsz % sizeof(Elf_Dyn) != 0)
>>>>>> goto dynamic_error;
>>>>>>
>>>>>> - tmp = phdr->p_memsz / sizeof(Elf32_Dyn);
>>>>>> - dyn = (Elf32_Dyn __user *)params->dynamic_addr;
>>>>>> + tmp = phdr->p_memsz / sizeof(Elf_Dyn);
>>>>>> + dyn = (Elf_Dyn __user *)params->dynamic_addr;
>>>>>> if (get_user(d_tag, &dyn[tmp - 1].d_tag) ||
>>>>>> d_tag != 0)
>>>>>> goto dynamic_error;
>>>>>> @@ -927,8 +927,8 @@ static int elf_fdpic_map_file_constdisp_on_uclinux(
>>>>>> struct file *file,
>>>>>> struct mm_struct *mm)
>>>>>> {
>>>>>> - struct elf32_fdpic_loadseg *seg;
>>>>>> - struct elf32_phdr *phdr;
>>>>>> + struct elf_fdpic_loadseg *seg;
>>>>>> + struct elf_phdr *phdr;
>>>>>> unsigned long load_addr, base = ULONG_MAX, top = 0, maddr = 0;
>>>>>> int loop, ret;
>>>>>>
>>>>>> @@ -1011,8 +1011,8 @@ static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *params,
>>>>>> struct file *file,
>>>>>> struct mm_struct *mm)
>>>>>> {
>>>>>> - struct elf32_fdpic_loadseg *seg;
>>>>>> - struct elf32_phdr *phdr;
>>>>>> + struct elf_fdpic_loadseg *seg;
>>>>>> + struct elf_phdr *phdr;
>>>>>> unsigned long load_addr, delta_vaddr;
>>>>>> int loop, dvset;
>>>>>>
>>>>>> diff --git a/include/linux/elf-fdpic.h b/include/linux/elf-fdpic.h
>>>>>> index 3bea95a1af537..e533f45131945 100644
>>>>>> --- a/include/linux/elf-fdpic.h
>>>>>> +++ b/include/linux/elf-fdpic.h
>>>>>> @@ -10,13 +10,25 @@
>>>>>>
>>>>>> #include <uapi/linux/elf-fdpic.h>
>>>>>>
>>>>>> +#if ELF_CLASS == ELFCLASS32
>>>>>> +#define Elf_Sword Elf32_Sword
>>>>>> +#define elf_fdpic_loadseg elf32_fdpic_loadseg
>>>>>> +#define elf_fdpic_loadmap elf32_fdpic_loadmap
>>>>>> +#define ELF_FDPIC_LOADMAP_VERSION ELF32_FDPIC_LOADMAP_VERSION
>>>>>> +#else
>>>>>> +#define Elf_Sword Elf64_Sxword
>>>>>> +#define elf_fdpic_loadmap elf64_fdpic_loadmap
>>>>>> +#define elf_fdpic_loadseg elf64_fdpic_loadseg
>>>>>> +#define ELF_FDPIC_LOADMAP_VERSION ELF64_FDPIC_LOADMAP_VERSION
>>>>>> +#endif
>>>>>> +
>>>>>> /*
>>>>>> * binfmt binary parameters structure
>>>>>> */
>>>>>> struct elf_fdpic_params {
>>>>>> struct elfhdr hdr; /* ref copy of ELF header */
>>>>>> struct elf_phdr *phdrs; /* ref copy of PT_PHDR table */
>>>>>> - struct elf32_fdpic_loadmap *loadmap; /* loadmap to be passed to userspace */
>>>>>> + struct elf_fdpic_loadmap *loadmap; /* loadmap to be passed to userspace */
>>>>>> unsigned long elfhdr_addr; /* mapped ELF header user address */
>>>>>> unsigned long ph_addr; /* mapped PT_PHDR user address */
>>>>>> unsigned long map_addr; /* mapped loadmap user address */
>>>>>> diff --git a/include/uapi/linux/elf-fdpic.h b/include/uapi/linux/elf-fdpic.h
>>>>>> index 4fcc6cfebe185..ec23f08711292 100644
>>>>>> --- a/include/uapi/linux/elf-fdpic.h
>>>>>> +++ b/include/uapi/linux/elf-fdpic.h
>>>>>> @@ -32,4 +32,19 @@ struct elf32_fdpic_loadmap {
>>>>>>
>>>>>> #define ELF32_FDPIC_LOADMAP_VERSION 0x0000
>>>>>>
>>>>>> +/* segment mappings for ELF FDPIC libraries/executables/interpreters */
>>>>>> +struct elf64_fdpic_loadseg {
>>>>>> + Elf64_Addr addr; /* core address to which mapped */
>>>>>> + Elf64_Addr p_vaddr; /* VMA recorded in file */
>>>>>> + Elf64_Word p_memsz; /* allocation size recorded in file */
>>>>>> +};
>>>>>> +
>>>>>> +struct elf64_fdpic_loadmap {
>>>>>> + Elf64_Half version; /* version of these structures, just in case... */
>>>>>> + Elf64_Half nsegs; /* number of segments */
>>>>>> + struct elf64_fdpic_loadseg segs[];
>>>>>> +};
>>>>>> +
>>>>>> +#define ELF64_FDPIC_LOADMAP_VERSION 0x0000
>>>>>> +
>>>>>> #endif /* _UAPI_LINUX_ELF_FDPIC_H */
>>>>>
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