| Message ID | 87jzb2tdb7.fsf_-_@email.froward.int.ebiederm.org (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | alpha/elf: Fix misc/setarch test of util-linux by removing 32bit support | expand |
On 1/10/25 16:16, Eric W. Biederman wrote: > > Richard Henderson <richard.henderson@linaro.org> writes[1]: > >> There was a Spec benchmark (I forget which) which was memory bound and ran >> twice as fast with 32-bit pointers. >> >> I copied the idea from DEC to the ELF abi, but never did all the other work >> to allow the toolchain to take advantage. >> >> Amusingly, a later Spec changed the benchmark data sets to not fit into a >> 32-bit address space, specifically because of this. >> >> I expect one could delete the ELF bit and personality and no one would >> notice. Not even the 10 remaining Alpha users. > > In [2] it was pointed out that parts of setarch weren't working > properly on alpha because it has it's own SET_PERSONALITY > implementation. In the discussion that followed Richard Henderson > pointed out that the 32bit pointer support for alpha was never > completed. > > Fix this by removing alpha's 32bit pointer support. > > As a bit of paranoia refuse to execute any alpha binaries that hafe > the EF_ALPHA_32BIT flag set. Just to fail explicitly in case someone > somewhere has binaries that trying to use alpha's 32bit pointer > support. > > [1] https://lkml.kernel.org/r/CAFXwXrkgu=4Qn-v1PjnOR4SG0oUb9LSa0g6QXpBq4ttm52pJOQ@mail.gmail.com > [2] https://lkml.kernel.org/r/20250103140148.370368-1-glaubitz@physik.fu-berlin.de > Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> Thanks for cleaning this up. Reviewed-by: Richard Henderson <richard.henderson@linaro.org> r~ > --- > arch/alpha/include/asm/elf.h | 6 +----- > arch/alpha/include/asm/pgtable.h | 2 +- > arch/alpha/include/asm/processor.h | 8 ++------ > arch/alpha/kernel/osf_sys.c | 11 ++--------- > 4 files changed, 6 insertions(+), 21 deletions(-) > > diff --git a/arch/alpha/include/asm/elf.h b/arch/alpha/include/asm/elf.h > index 4d7c46f50382..50c82187e60e 100644 > --- a/arch/alpha/include/asm/elf.h > +++ b/arch/alpha/include/asm/elf.h > @@ -74,7 +74,7 @@ typedef elf_fpreg_t elf_fpregset_t[ELF_NFPREG]; > /* > * This is used to ensure we don't load something for the wrong architecture. > */ > -#define elf_check_arch(x) ((x)->e_machine == EM_ALPHA) > +#define elf_check_arch(x) (((x)->e_machine == EM_ALPHA) && !((x)->e_flags & EF_ALPHA_32BIT)) > > /* > * These are used to set parameters in the core dumps. > @@ -137,10 +137,6 @@ extern int dump_elf_task(elf_greg_t *dest, struct task_struct *task); > : amask (AMASK_CIX) ? "ev6" : "ev67"); \ > }) > > -#define SET_PERSONALITY(EX) \ > - set_personality(((EX).e_flags & EF_ALPHA_32BIT) \ > - ? PER_LINUX_32BIT : PER_LINUX) > - > extern int alpha_l1i_cacheshape; > extern int alpha_l1d_cacheshape; > extern int alpha_l2_cacheshape; > diff --git a/arch/alpha/include/asm/pgtable.h b/arch/alpha/include/asm/pgtable.h > index 635f0a5f5bbd..02e8817a8921 100644 > --- a/arch/alpha/include/asm/pgtable.h > +++ b/arch/alpha/include/asm/pgtable.h > @@ -360,7 +360,7 @@ static inline pte_t pte_swp_clear_exclusive(pte_t pte) > > extern void paging_init(void); > > -/* We have our own get_unmapped_area to cope with ADDR_LIMIT_32BIT. */ > +/* We have our own get_unmapped_area */ > #define HAVE_ARCH_UNMAPPED_AREA > > #endif /* _ALPHA_PGTABLE_H */ > diff --git a/arch/alpha/include/asm/processor.h b/arch/alpha/include/asm/processor.h > index 55bb1c09fd39..5dce5518a211 100644 > --- a/arch/alpha/include/asm/processor.h > +++ b/arch/alpha/include/asm/processor.h > @@ -8,23 +8,19 @@ > #ifndef __ASM_ALPHA_PROCESSOR_H > #define __ASM_ALPHA_PROCESSOR_H > > -#include <linux/personality.h> /* for ADDR_LIMIT_32BIT */ > - > /* > * We have a 42-bit user address space: 4TB user VM... > */ > #define TASK_SIZE (0x40000000000UL) > > -#define STACK_TOP \ > - (current->personality & ADDR_LIMIT_32BIT ? 0x80000000 : 0x00120000000UL) > +#define STACK_TOP (0x00120000000UL) > > #define STACK_TOP_MAX 0x00120000000UL > > /* This decides where the kernel will search for a free chunk of vm > * space during mmap's. > */ > -#define TASK_UNMAPPED_BASE \ > - ((current->personality & ADDR_LIMIT_32BIT) ? 0x40000000 : TASK_SIZE / 2) > +#define TASK_UNMAPPED_BASE (TASK_SIZE / 2) > > /* This is dead. Everything has been moved to thread_info. */ > struct thread_struct { }; > diff --git a/arch/alpha/kernel/osf_sys.c b/arch/alpha/kernel/osf_sys.c > index 86185021f75a..a08e8edef1a4 100644 > --- a/arch/alpha/kernel/osf_sys.c > +++ b/arch/alpha/kernel/osf_sys.c > @@ -1210,8 +1210,7 @@ SYSCALL_DEFINE1(old_adjtimex, struct timex32 __user *, txc_p) > return ret; > } > > -/* Get an address range which is currently unmapped. Similar to the > - generic version except that we know how to honor ADDR_LIMIT_32BIT. */ > +/* Get an address range which is currently unmapped. */ > > static unsigned long > arch_get_unmapped_area_1(unsigned long addr, unsigned long len, > @@ -1230,13 +1229,7 @@ arch_get_unmapped_area(struct file *filp, unsigned long addr, > unsigned long len, unsigned long pgoff, > unsigned long flags, vm_flags_t vm_flags) > { > - unsigned long limit; > - > - /* "32 bit" actually means 31 bit, since pointers sign extend. */ > - if (current->personality & ADDR_LIMIT_32BIT) > - limit = 0x80000000; > - else > - limit = TASK_SIZE; > + unsigned long limit = TASK_SIZE; > > if (len > limit) > return -ENOMEM;
diff --git a/arch/alpha/include/asm/elf.h b/arch/alpha/include/asm/elf.h index 4d7c46f50382..50c82187e60e 100644 --- a/arch/alpha/include/asm/elf.h +++ b/arch/alpha/include/asm/elf.h @@ -74,7 +74,7 @@ typedef elf_fpreg_t elf_fpregset_t[ELF_NFPREG]; /* * This is used to ensure we don't load something for the wrong architecture. */ -#define elf_check_arch(x) ((x)->e_machine == EM_ALPHA) +#define elf_check_arch(x) (((x)->e_machine == EM_ALPHA) && !((x)->e_flags & EF_ALPHA_32BIT)) /* * These are used to set parameters in the core dumps. @@ -137,10 +137,6 @@ extern int dump_elf_task(elf_greg_t *dest, struct task_struct *task); : amask (AMASK_CIX) ? "ev6" : "ev67"); \ }) -#define SET_PERSONALITY(EX) \ - set_personality(((EX).e_flags & EF_ALPHA_32BIT) \ - ? PER_LINUX_32BIT : PER_LINUX) - extern int alpha_l1i_cacheshape; extern int alpha_l1d_cacheshape; extern int alpha_l2_cacheshape; diff --git a/arch/alpha/include/asm/pgtable.h b/arch/alpha/include/asm/pgtable.h index 635f0a5f5bbd..02e8817a8921 100644 --- a/arch/alpha/include/asm/pgtable.h +++ b/arch/alpha/include/asm/pgtable.h @@ -360,7 +360,7 @@ static inline pte_t pte_swp_clear_exclusive(pte_t pte) extern void paging_init(void); -/* We have our own get_unmapped_area to cope with ADDR_LIMIT_32BIT. */ +/* We have our own get_unmapped_area */ #define HAVE_ARCH_UNMAPPED_AREA #endif /* _ALPHA_PGTABLE_H */ diff --git a/arch/alpha/include/asm/processor.h b/arch/alpha/include/asm/processor.h index 55bb1c09fd39..5dce5518a211 100644 --- a/arch/alpha/include/asm/processor.h +++ b/arch/alpha/include/asm/processor.h @@ -8,23 +8,19 @@ #ifndef __ASM_ALPHA_PROCESSOR_H #define __ASM_ALPHA_PROCESSOR_H -#include <linux/personality.h> /* for ADDR_LIMIT_32BIT */ - /* * We have a 42-bit user address space: 4TB user VM... */ #define TASK_SIZE (0x40000000000UL) -#define STACK_TOP \ - (current->personality & ADDR_LIMIT_32BIT ? 0x80000000 : 0x00120000000UL) +#define STACK_TOP (0x00120000000UL) #define STACK_TOP_MAX 0x00120000000UL /* This decides where the kernel will search for a free chunk of vm * space during mmap's. */ -#define TASK_UNMAPPED_BASE \ - ((current->personality & ADDR_LIMIT_32BIT) ? 0x40000000 : TASK_SIZE / 2) +#define TASK_UNMAPPED_BASE (TASK_SIZE / 2) /* This is dead. Everything has been moved to thread_info. */ struct thread_struct { }; diff --git a/arch/alpha/kernel/osf_sys.c b/arch/alpha/kernel/osf_sys.c index 86185021f75a..a08e8edef1a4 100644 --- a/arch/alpha/kernel/osf_sys.c +++ b/arch/alpha/kernel/osf_sys.c @@ -1210,8 +1210,7 @@ SYSCALL_DEFINE1(old_adjtimex, struct timex32 __user *, txc_p) return ret; } -/* Get an address range which is currently unmapped. Similar to the - generic version except that we know how to honor ADDR_LIMIT_32BIT. */ +/* Get an address range which is currently unmapped. */ static unsigned long arch_get_unmapped_area_1(unsigned long addr, unsigned long len, @@ -1230,13 +1229,7 @@ arch_get_unmapped_area(struct file *filp, unsigned long addr, unsigned long len, unsigned long pgoff, unsigned long flags, vm_flags_t vm_flags) { - unsigned long limit; - - /* "32 bit" actually means 31 bit, since pointers sign extend. */ - if (current->personality & ADDR_LIMIT_32BIT) - limit = 0x80000000; - else - limit = TASK_SIZE; + unsigned long limit = TASK_SIZE; if (len > limit) return -ENOMEM;