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Commit ec23847d authored by Paul Mundt's avatar Paul Mundt Committed by Linus Torvalds
Browse files

binfmt_elf_fdpic: support auxvec base platform string 



Commit 483fad1c ("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: default avatarPaul Mundt <lethal@linux-sh.org>
Acked-by: default avatarDavid Howells <dhowells@redhat.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 758222f8

fs/binfmt_elf_fdpic.c

+43 −7
Original line number Diff line number Diff line
@@ -455,6 +455,16 @@ static int load_elf_fdpic_binary(struct linux_binprm *bprm, 
}



/*****************************************************************************/



#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);