binfmt_elf_fdpic: support auxvec base platform string

Commit 483fad1c3fa1060d7e6710e84a065ad514571739 ("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>

binfmt_elf_fdpic: support auxvec base platform string
Commit 483fad1c3fa1060d7e6710e84a065ad514571739 ("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>
Paul Mundt · Linus Torvalds
1 parent 758222f842
Showing 1 changed file with 43 additions and 7 deletions Side-by-side Diff
fs/binfmt_elf_fdpic.c
@@ -455,7 +455,17 @@
 }
  
 /*****************************************************************************/
+
+#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
  */
 static int create_elf_fdpic_tables(struct linux_binprm *bprm,
@@ -466,8 +476,8 @@
 	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 @@
 		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 @@
 			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 @@
 	/* 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);
@@ -573,6 +602,13 @@
 		csp -= 2 * sizeof(unsigned long);
 		NEW_AUX_ENT(AT_PLATFORM,
 			    (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;
...	...	@@ -455,7 +455,17 @@
455	455	}
456	456
457	457	/*****************************************************************************/
	458	+
	459	+#ifndef ELF_BASE_PLATFORM
458	460	/*
	461	+ * AT_BASE_PLATFORM indicates the "real" hardware/microarchitecture.
	462	+ * If the arch defines ELF_BASE_PLATFORM (in asm/elf.h), the value
	463	+ * will be copied to the user stack in the same manner as AT_PLATFORM.
	464	+ */
	465	+#define ELF_BASE_PLATFORM NULL
	466	+#endif
	467	+
	468	+/*
459	469	* present useful information to the program
460	470	*/
461	471	static int create_elf_fdpic_tables(struct linux_binprm *bprm,
...	...	@@ -466,8 +476,8 @@
466	476	unsigned long sp, csp, nitems;
467	477	elf_caddr_t __user argv, envp;
468	478	size_t platform_len = 0, len;
469		- char *k_platform;
470		- char __user u_platform, p;
	479	+ char k_platform, k_base_platform;
	480	+ char __user u_platform, u_base_platform, *p;
471	481	long hwcap;
472	482	int loop;
473	483	int nr; /* reset for each csp adjustment */
474	484
...	...	@@ -483,11 +493,14 @@
483	493	return -EFAULT;
484	494	#endif
485	495
486		- /* get hold of platform and hardware capabilities masks for the machine
487		- * we are running on. In some cases (Sparc), this info is impossible
488		- * to get, in others (i386) it is merely difficult.
489		- */
490	496	hwcap = ELF_HWCAP;
	497	+
	498	+ /*
	499	+ * If this architecture has a platform capability string, copy it
	500	+ * to userspace. In some cases (Sparc), this info is impossible
	501	+ * for userspace to get any other way, in others (i386) it is
	502	+ * merely difficult.
	503	+ */
491	504	k_platform = ELF_PLATFORM;
492	505	u_platform = NULL;
493	506
...	...	@@ -499,6 +512,21 @@
499	512	return -EFAULT;
500	513	}
501	514
	515	+ /*
	516	+ * If this architecture has a "base" platform capability
	517	+ * string, copy it to userspace.
	518	+ */
	519	+ k_base_platform = ELF_BASE_PLATFORM;
	520	+ u_base_platform = NULL;
	521	+
	522	+ if (k_base_platform) {
	523	+ platform_len = strlen(k_base_platform) + 1;
	524	+ sp -= platform_len;
	525	+ u_base_platform = (char __user *) sp;
	526	+ if (__copy_to_user(u_base_platform, k_base_platform, platform_len) != 0)
	527	+ return -EFAULT;
	528	+ }
	529	+
502	530	#if defined(__i386__) && defined(CONFIG_SMP)
503	531	/* in some cases (e.g. Hyper-Threading), we want to avoid L1 evictions
504	532	* by the processes running on the same package. One thing we can do is
...	...	@@ -543,7 +571,8 @@
543	571	/* force 16 byte _final_ alignment here for generality */
544	572	#define DLINFO_ITEMS 13
545	573
546		- nitems = 1 + DLINFO_ITEMS + (k_platform ? 1 : 0) + AT_VECTOR_SIZE_ARCH;
	574	+ nitems = 1 + DLINFO_ITEMS + (k_platform ? 1 : 0) +
	575	+ (k_base_platform ? 1 : 0) + AT_VECTOR_SIZE_ARCH;
547	576
548	577	csp = sp;
549	578	sp -= nitems * 2 * sizeof(unsigned long);
...	...	@@ -573,6 +602,13 @@
573	602	csp -= 2 * sizeof(unsigned long);
574	603	NEW_AUX_ENT(AT_PLATFORM,
575	604	(elf_addr_t) (unsigned long) u_platform);
	605	+ }
	606	+
	607	+ if (k_base_platform) {
	608	+ nr = 0;
	609	+ csp -= 2 * sizeof(unsigned long);
	610	+ NEW_AUX_ENT(AT_BASE_PLATFORM,
	611	+ (elf_addr_t) (unsigned long) u_base_platform);
576	612	}
577	613
578	614	nr = 0;