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binfmt_elf_fdpic: support auxvec base platform string

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Commit 483fad1c3f ("ELF loader support for
auxvec base platform string") introduced AT_BASE_PLATFORM, but only
implemented it for binfmt_elf.

Given that AT_VECTOR_SIZE_BASE is unconditionally enlarged for us, and
it's only optionally added in for the platforms that set
ELF_BASE_PLATFORM, wire it up for binfmt_elf_fdpic, too.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Acked-by: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Paul Mundt 2008-10-15 22:04:15 -07:00 committed by Linus Torvalds
parent 758222f842
commit ec23847d6c
1 changed files with 43 additions and 7 deletions
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50
fs/binfmt_elf_fdpic.c
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@ -455,6 +455,16 @@ error_kill:
}
/*****************************************************************************/
#ifndef ELF_BASE_PLATFORM
/*
* AT_BASE_PLATFORM indicates the "real" hardware/microarchitecture.
* If the arch defines ELF_BASE_PLATFORM (in asm/elf.h), the value
* will be copied to the user stack in the same manner as AT_PLATFORM.
*/
#define ELF_BASE_PLATFORM NULL
#endif
/*
* present useful information to the program
*/
@ -466,8 +476,8 @@ static int create_elf_fdpic_tables(struct linux_binprm *bprm,
unsigned long sp, csp, nitems;
elf_caddr_t __user *argv, *envp;
size_t platform_len = 0, len;
char *k_platform;
char __user *u_platform, *p;
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 */
@ -483,11 +493,14 @@ static int create_elf_fdpic_tables(struct linux_binprm *bprm,
return -EFAULT;
#endif
/* get hold of platform and hardware capabilities masks for the machine
* we are running on. In some cases (Sparc), this info is impossible
* to get, in others (i386) it is merely difficult.
*/
hwcap = ELF_HWCAP;
/*
* If this architecture has a platform capability string, copy it
* to userspace. In some cases (Sparc), this info is impossible
* for userspace to get any other way, in others (i386) it is
* merely difficult.
*/
k_platform = ELF_PLATFORM;
u_platform = NULL;
@ -499,6 +512,21 @@ static int create_elf_fdpic_tables(struct linux_binprm *bprm,
return -EFAULT;
}
/*
* If this architecture has a "base" platform capability
* string, copy it to userspace.
*/
k_base_platform = ELF_BASE_PLATFORM;
u_base_platform = NULL;
if (k_base_platform) {
platform_len = strlen(k_base_platform) + 1;
sp -= platform_len;
u_base_platform = (char __user *) sp;
if (__copy_to_user(u_base_platform, k_base_platform, platform_len) != 0)
return -EFAULT;
}
#if defined(__i386__) && defined(CONFIG_SMP)
/* in some cases (e.g. Hyper-Threading), we want to avoid L1 evictions
* by the processes running on the same package. One thing we can do is
@ -543,7 +571,8 @@ static int create_elf_fdpic_tables(struct linux_binprm *bprm,
/* force 16 byte _final_ alignment here for generality */
#define DLINFO_ITEMS 13
nitems = 1 + DLINFO_ITEMS + (k_platform ? 1 : 0) + AT_VECTOR_SIZE_ARCH;
nitems = 1 + DLINFO_ITEMS + (k_platform ? 1 : 0) +
(k_base_platform ? 1 : 0) + AT_VECTOR_SIZE_ARCH;
csp = sp;
sp -= nitems * 2 * sizeof(unsigned long);
@ -575,6 +604,13 @@ static int create_elf_fdpic_tables(struct linux_binprm *bprm,
(elf_addr_t) (unsigned long) u_platform);
}
if (k_base_platform) {
nr = 0;
csp -= 2 * sizeof(unsigned long);
NEW_AUX_ENT(AT_BASE_PLATFORM,
(elf_addr_t) (unsigned long) u_base_platform);
}
nr = 0;
csp -= DLINFO_ITEMS * 2 * sizeof(unsigned long);
NEW_AUX_ENT(AT_HWCAP, hwcap);