We are currently out of free bits in AT_HWCAP. With POWER8, we have
several hardware features that we need to advertise.
Tested on POWER and x86.
Signed-off-by: Michael Neuling <[email protected]>
Signed-off-by: Nishanth Aravamudan <[email protected]>
---
> Wouldn't it be safer to not emit AT_HWCAP2 unless it is defined by the arch?
>
> That way the change would only impact powerpc.
Should be addressed with this version.
Mikey
diff --git a/arch/powerpc/include/asm/cputable.h b/arch/powerpc/include/asm/cputable.h
index fb3245e..ccadad6 100644
--- a/arch/powerpc/include/asm/cputable.h
+++ b/arch/powerpc/include/asm/cputable.h
@@ -52,6 +52,7 @@ struct cpu_spec {
char *cpu_name;
unsigned long cpu_features; /* Kernel features */
unsigned int cpu_user_features; /* Userland features */
+ unsigned int cpu_user_features2; /* Userland features v2 */
unsigned int mmu_features; /* MMU features */
/* cache line sizes */
diff --git a/arch/powerpc/include/asm/elf.h b/arch/powerpc/include/asm/elf.h
index ac9790f..cc0655a 100644
--- a/arch/powerpc/include/asm/elf.h
+++ b/arch/powerpc/include/asm/elf.h
@@ -61,6 +61,7 @@ typedef elf_vrregset_t elf_fpxregset_t;
instruction set this cpu supports. This could be done in userspace,
but it's not easy, and we've already done it here. */
# define ELF_HWCAP (cur_cpu_spec->cpu_user_features)
+# define ELF_HWCAP2 (cur_cpu_spec->cpu_user_features2)
/* This yields a string that ld.so will use to load implementation
specific libraries for optimization. This is more specific in
diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c
index 3939829..1f8b5d5 100644
--- a/fs/binfmt_elf.c
+++ b/fs/binfmt_elf.c
@@ -240,6 +240,9 @@ create_elf_tables(struct linux_binprm *bprm, struct elfhdr *exec,
NEW_AUX_ENT(AT_EGID, from_kgid_munged(cred->user_ns, cred->egid));
NEW_AUX_ENT(AT_SECURE, security_bprm_secureexec(bprm));
NEW_AUX_ENT(AT_RANDOM, (elf_addr_t)(unsigned long)u_rand_bytes);
+#ifdef ELF_HWCAP2
+ NEW_AUX_ENT(AT_HWCAP2, ELF_HWCAP2);
+#endif
NEW_AUX_ENT(AT_EXECFN, bprm->exec);
if (k_platform) {
NEW_AUX_ENT(AT_PLATFORM,
diff --git a/fs/binfmt_elf_fdpic.c b/fs/binfmt_elf_fdpic.c
index 9c13e02..bf2381d 100644
--- a/fs/binfmt_elf_fdpic.c
+++ b/fs/binfmt_elf_fdpic.c
@@ -483,7 +483,6 @@ static int create_elf_fdpic_tables(struct linux_binprm *bprm,
size_t platform_len = 0, len;
char *k_platform, *k_base_platform;
char __user *u_platform, *u_base_platform, *p;
- long hwcap;
int loop;
int nr; /* reset for each csp adjustment */
@@ -502,8 +501,6 @@ static int create_elf_fdpic_tables(struct linux_binprm *bprm,
return -EFAULT;
#endif
- hwcap = ELF_HWCAP;
-
/*
* If this architecture has a platform capability string, copy it
* to userspace. In some cases (Sparc), this info is impossible
@@ -617,7 +614,10 @@ static int create_elf_fdpic_tables(struct linux_binprm *bprm,
nr = 0;
csp -= DLINFO_ITEMS * 2 * sizeof(unsigned long);
- NEW_AUX_ENT(AT_HWCAP, hwcap);
+ NEW_AUX_ENT(AT_HWCAP, ELF_HWCAP);
+#ifdef ELF_HWCAP2
+ NEW_AUX_ENT(AT_HWCAP2, ELF_HWCAP2);
+#endif
NEW_AUX_ENT(AT_PAGESZ, PAGE_SIZE);
NEW_AUX_ENT(AT_CLKTCK, CLOCKS_PER_SEC);
NEW_AUX_ENT(AT_PHDR, exec_params->ph_addr);
diff --git a/include/uapi/linux/auxvec.h b/include/uapi/linux/auxvec.h
index 61594d5..835c065 100644
--- a/include/uapi/linux/auxvec.h
+++ b/include/uapi/linux/auxvec.h
@@ -28,6 +28,7 @@
#define AT_BASE_PLATFORM 24 /* string identifying real platform, may
* differ from AT_PLATFORM. */
#define AT_RANDOM 25 /* address of 16 random bytes */
+#define AT_HWCAP2 26 /* extension of AT_HWCAP */
#define AT_EXECFN 31 /* filename of program */
akpm,
If you're happy with this, is it something you can take in your tree?
Mikey
Michael Neuling <[email protected]> wrote:
> We are currently out of free bits in AT_HWCAP. With POWER8, we have
> several hardware features that we need to advertise.
>
> Tested on POWER and x86.
>
> Signed-off-by: Michael Neuling <[email protected]>
> Signed-off-by: Nishanth Aravamudan <[email protected]>
> ---
>
> > Wouldn't it be safer to not emit AT_HWCAP2 unless it is defined by the arch?
> >
> > That way the change would only impact powerpc.
>
> Should be addressed with this version.
>
> Mikey
>
> diff --git a/arch/powerpc/include/asm/cputable.h b/arch/powerpc/include/asm/cputable.h
> index fb3245e..ccadad6 100644
> --- a/arch/powerpc/include/asm/cputable.h
> +++ b/arch/powerpc/include/asm/cputable.h
> @@ -52,6 +52,7 @@ struct cpu_spec {
> char *cpu_name;
> unsigned long cpu_features; /* Kernel features */
> unsigned int cpu_user_features; /* Userland features */
> + unsigned int cpu_user_features2; /* Userland features v2 */
> unsigned int mmu_features; /* MMU features */
>
> /* cache line sizes */
> diff --git a/arch/powerpc/include/asm/elf.h b/arch/powerpc/include/asm/elf.h
> index ac9790f..cc0655a 100644
> --- a/arch/powerpc/include/asm/elf.h
> +++ b/arch/powerpc/include/asm/elf.h
> @@ -61,6 +61,7 @@ typedef elf_vrregset_t elf_fpxregset_t;
> instruction set this cpu supports. This could be done in userspace,
> but it's not easy, and we've already done it here. */
> # define ELF_HWCAP (cur_cpu_spec->cpu_user_features)
> +# define ELF_HWCAP2 (cur_cpu_spec->cpu_user_features2)
>
> /* This yields a string that ld.so will use to load implementation
> specific libraries for optimization. This is more specific in
> diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c
> index 3939829..1f8b5d5 100644
> --- a/fs/binfmt_elf.c
> +++ b/fs/binfmt_elf.c
> @@ -240,6 +240,9 @@ create_elf_tables(struct linux_binprm *bprm, struct elfhdr *exec,
> NEW_AUX_ENT(AT_EGID, from_kgid_munged(cred->user_ns, cred->egid));
> NEW_AUX_ENT(AT_SECURE, security_bprm_secureexec(bprm));
> NEW_AUX_ENT(AT_RANDOM, (elf_addr_t)(unsigned long)u_rand_bytes);
> +#ifdef ELF_HWCAP2
> + NEW_AUX_ENT(AT_HWCAP2, ELF_HWCAP2);
> +#endif
> NEW_AUX_ENT(AT_EXECFN, bprm->exec);
> if (k_platform) {
> NEW_AUX_ENT(AT_PLATFORM,
> diff --git a/fs/binfmt_elf_fdpic.c b/fs/binfmt_elf_fdpic.c
> index 9c13e02..bf2381d 100644
> --- a/fs/binfmt_elf_fdpic.c
> +++ b/fs/binfmt_elf_fdpic.c
> @@ -483,7 +483,6 @@ static int create_elf_fdpic_tables(struct linux_binprm *bprm,
> size_t platform_len = 0, len;
> char *k_platform, *k_base_platform;
> char __user *u_platform, *u_base_platform, *p;
> - long hwcap;
> int loop;
> int nr; /* reset for each csp adjustment */
>
> @@ -502,8 +501,6 @@ static int create_elf_fdpic_tables(struct linux_binprm *bprm,
> return -EFAULT;
> #endif
>
> - hwcap = ELF_HWCAP;
> -
> /*
> * If this architecture has a platform capability string, copy it
> * to userspace. In some cases (Sparc), this info is impossible
> @@ -617,7 +614,10 @@ static int create_elf_fdpic_tables(struct linux_binprm *bprm,
>
> nr = 0;
> csp -= DLINFO_ITEMS * 2 * sizeof(unsigned long);
> - NEW_AUX_ENT(AT_HWCAP, hwcap);
> + NEW_AUX_ENT(AT_HWCAP, ELF_HWCAP);
> +#ifdef ELF_HWCAP2
> + NEW_AUX_ENT(AT_HWCAP2, ELF_HWCAP2);
> +#endif
> NEW_AUX_ENT(AT_PAGESZ, PAGE_SIZE);
> NEW_AUX_ENT(AT_CLKTCK, CLOCKS_PER_SEC);
> NEW_AUX_ENT(AT_PHDR, exec_params->ph_addr);
> diff --git a/include/uapi/linux/auxvec.h b/include/uapi/linux/auxvec.h
> index 61594d5..835c065 100644
> --- a/include/uapi/linux/auxvec.h
> +++ b/include/uapi/linux/auxvec.h
> @@ -28,6 +28,7 @@
> #define AT_BASE_PLATFORM 24 /* string identifying real platform, may
> * differ from AT_PLATFORM. */
> #define AT_RANDOM 25 /* address of 16 random bytes */
> +#define AT_HWCAP2 26 /* extension of AT_HWCAP */
>
> #define AT_EXECFN 31 /* filename of program */
>
> _______________________________________________
> Linuxppc-dev mailing list
> [email protected]
> https://lists.ozlabs.org/listinfo/linuxppc-dev
>
On Thu, 2013-04-18 at 13:41 +1000, Michael Neuling wrote:
> akpm,
>
> If you're happy with this, is it something you can take in your tree?
Andrew ? Or give me an ack ? :-) I'm happy to carry this, we need that
rather urgently and we have the glibc folks on board.
Cheers,
Ben.
> Mikey
>
> Michael Neuling <[email protected]> wrote:
> > We are currently out of free bits in AT_HWCAP. With POWER8, we have
> > several hardware features that we need to advertise.
> >
> > Tested on POWER and x86.
> >
> > Signed-off-by: Michael Neuling <[email protected]>
> > Signed-off-by: Nishanth Aravamudan <[email protected]>
> > ---
> >
> > > Wouldn't it be safer to not emit AT_HWCAP2 unless it is defined by the arch?
> > >
> > > That way the change would only impact powerpc.
> >
> > Should be addressed with this version.
> >
> > Mikey
> >
> > diff --git a/arch/powerpc/include/asm/cputable.h b/arch/powerpc/include/asm/cputable.h
> > index fb3245e..ccadad6 100644
> > --- a/arch/powerpc/include/asm/cputable.h
> > +++ b/arch/powerpc/include/asm/cputable.h
> > @@ -52,6 +52,7 @@ struct cpu_spec {
> > char *cpu_name;
> > unsigned long cpu_features; /* Kernel features */
> > unsigned int cpu_user_features; /* Userland features */
> > + unsigned int cpu_user_features2; /* Userland features v2 */
> > unsigned int mmu_features; /* MMU features */
> >
> > /* cache line sizes */
> > diff --git a/arch/powerpc/include/asm/elf.h b/arch/powerpc/include/asm/elf.h
> > index ac9790f..cc0655a 100644
> > --- a/arch/powerpc/include/asm/elf.h
> > +++ b/arch/powerpc/include/asm/elf.h
> > @@ -61,6 +61,7 @@ typedef elf_vrregset_t elf_fpxregset_t;
> > instruction set this cpu supports. This could be done in userspace,
> > but it's not easy, and we've already done it here. */
> > # define ELF_HWCAP (cur_cpu_spec->cpu_user_features)
> > +# define ELF_HWCAP2 (cur_cpu_spec->cpu_user_features2)
> >
> > /* This yields a string that ld.so will use to load implementation
> > specific libraries for optimization. This is more specific in
> > diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c
> > index 3939829..1f8b5d5 100644
> > --- a/fs/binfmt_elf.c
> > +++ b/fs/binfmt_elf.c
> > @@ -240,6 +240,9 @@ create_elf_tables(struct linux_binprm *bprm, struct elfhdr *exec,
> > NEW_AUX_ENT(AT_EGID, from_kgid_munged(cred->user_ns, cred->egid));
> > NEW_AUX_ENT(AT_SECURE, security_bprm_secureexec(bprm));
> > NEW_AUX_ENT(AT_RANDOM, (elf_addr_t)(unsigned long)u_rand_bytes);
> > +#ifdef ELF_HWCAP2
> > + NEW_AUX_ENT(AT_HWCAP2, ELF_HWCAP2);
> > +#endif
> > NEW_AUX_ENT(AT_EXECFN, bprm->exec);
> > if (k_platform) {
> > NEW_AUX_ENT(AT_PLATFORM,
> > diff --git a/fs/binfmt_elf_fdpic.c b/fs/binfmt_elf_fdpic.c
> > index 9c13e02..bf2381d 100644
> > --- a/fs/binfmt_elf_fdpic.c
> > +++ b/fs/binfmt_elf_fdpic.c
> > @@ -483,7 +483,6 @@ static int create_elf_fdpic_tables(struct linux_binprm *bprm,
> > size_t platform_len = 0, len;
> > char *k_platform, *k_base_platform;
> > char __user *u_platform, *u_base_platform, *p;
> > - long hwcap;
> > int loop;
> > int nr; /* reset for each csp adjustment */
> >
> > @@ -502,8 +501,6 @@ static int create_elf_fdpic_tables(struct linux_binprm *bprm,
> > return -EFAULT;
> > #endif
> >
> > - hwcap = ELF_HWCAP;
> > -
> > /*
> > * If this architecture has a platform capability string, copy it
> > * to userspace. In some cases (Sparc), this info is impossible
> > @@ -617,7 +614,10 @@ static int create_elf_fdpic_tables(struct linux_binprm *bprm,
> >
> > nr = 0;
> > csp -= DLINFO_ITEMS * 2 * sizeof(unsigned long);
> > - NEW_AUX_ENT(AT_HWCAP, hwcap);
> > + NEW_AUX_ENT(AT_HWCAP, ELF_HWCAP);
> > +#ifdef ELF_HWCAP2
> > + NEW_AUX_ENT(AT_HWCAP2, ELF_HWCAP2);
> > +#endif
> > NEW_AUX_ENT(AT_PAGESZ, PAGE_SIZE);
> > NEW_AUX_ENT(AT_CLKTCK, CLOCKS_PER_SEC);
> > NEW_AUX_ENT(AT_PHDR, exec_params->ph_addr);
> > diff --git a/include/uapi/linux/auxvec.h b/include/uapi/linux/auxvec.h
> > index 61594d5..835c065 100644
> > --- a/include/uapi/linux/auxvec.h
> > +++ b/include/uapi/linux/auxvec.h
> > @@ -28,6 +28,7 @@
> > #define AT_BASE_PLATFORM 24 /* string identifying real platform, may
> > * differ from AT_PLATFORM. */
> > #define AT_RANDOM 25 /* address of 16 random bytes */
> > +#define AT_HWCAP2 26 /* extension of AT_HWCAP */
> >
> > #define AT_EXECFN 31 /* filename of program */
> >
> > _______________________________________________
> > Linuxppc-dev mailing list
> > [email protected]
> > https://lists.ozlabs.org/listinfo/linuxppc-dev
> >
> _______________________________________________
> Linuxppc-dev mailing list
> [email protected]
> https://lists.ozlabs.org/listinfo/linuxppc-dev
On Tue, 23 Apr 2013 10:41:42 +1000 Benjamin Herrenschmidt <[email protected]> wrote:
> On Thu, 2013-04-18 at 13:41 +1000, Michael Neuling wrote:
> > akpm,
> >
> > If you're happy with this, is it something you can take in your tree?
>
> Andrew ? Or give me an ack ? :-) I'm happy to carry this, we need that
> rather urgently and we have the glibc folks on board.
Looks good to me - please proceed with the patch.