From: Robin Holt <holt@sgi.com>
Date: Tue, 6 Dec 2005 02:02:31 +0000 (-0600)
Subject: [IA64] Change SET_PERSONALITY to comply with comment in binfmt_elf.c.
X-Git-Tag: v2.6.15-rc6~97^2~3
X-Git-Url: http://bbs.cooldavid.org/git/?a=commitdiff_plain;h=bd1d6e2451f2bb0132416fda4d129c4f57a827bc;p=net-next-2.6.git

[IA64] Change SET_PERSONALITY to comply with comment in binfmt_elf.c.

We have a customer application which trips a bug.  The problem arises
when a driver attempts to call do_munmap on an area which is mapped, but
because current->thread.task_size has been set to 0xC0000000, the call
to do_munmap fails thinking it is an unmap beyond the user's address
space.

The comment in fs/binfmt_elf.c in load_elf_library() before the call
to SET_PERSONALITY() indicates that task_size must not be changed for
the running application until flush_thread, but is for ia64 executing
ia32 binaries.

This patch moves the setting of task_size from SET_PERSONALITY() to
flush_thread() as indicated.  The customer application no longer is able
to trip the bug.

Signed-off-by: Robin Holt <holt@sgi.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
---

diff --git a/arch/ia64/ia32/binfmt_elf32.c b/arch/ia64/ia32/binfmt_elf32.c
index a7280d9f6c1..4e7a6a1ec6c 100644
--- a/arch/ia64/ia32/binfmt_elf32.c
+++ b/arch/ia64/ia32/binfmt_elf32.c
@@ -261,8 +261,6 @@ elf32_set_personality (void)
 {
 	set_personality(PER_LINUX32);
 	current->thread.map_base  = IA32_PAGE_OFFSET/3;
-	current->thread.task_size = IA32_PAGE_OFFSET;	/* use what Linux/x86 uses... */
-	set_fs(USER_DS);				/* set addr limit for new TASK_SIZE */
 }
 
 static unsigned long
diff --git a/arch/ia64/ia32/ia32priv.h b/arch/ia64/ia32/ia32priv.h
index e3e9290e3ff..68ceb4e690c 100644
--- a/arch/ia64/ia32/ia32priv.h
+++ b/arch/ia64/ia32/ia32priv.h
@@ -305,7 +305,6 @@ struct old_linux32_dirent {
 #define ELF_DATA	ELFDATA2LSB
 #define ELF_ARCH	EM_386
 
-#define IA32_PAGE_OFFSET	0xc0000000
 #define IA32_STACK_TOP		IA32_PAGE_OFFSET
 #define IA32_GATE_OFFSET	IA32_PAGE_OFFSET
 #define IA32_GATE_END		IA32_PAGE_OFFSET + PAGE_SIZE
diff --git a/arch/ia64/kernel/process.c b/arch/ia64/kernel/process.c
index 2e33665d9c1..a4da715a360 100644
--- a/arch/ia64/kernel/process.c
+++ b/arch/ia64/kernel/process.c
@@ -721,8 +721,11 @@ flush_thread (void)
 	/* drop floating-point and debug-register state if it exists: */
 	current->thread.flags &= ~(IA64_THREAD_FPH_VALID | IA64_THREAD_DBG_VALID);
 	ia64_drop_fpu(current);
-	if (IS_IA32_PROCESS(ia64_task_regs(current)))
+	if (IS_IA32_PROCESS(ia64_task_regs(current))) {
 		ia32_drop_partial_page_list(current);
+		current->thread.task_size = IA32_PAGE_OFFSET;
+		set_fs(USER_DS);
+	}
 }
 
 /*
diff --git a/include/asm-ia64/ia32.h b/include/asm-ia64/ia32.h
index 8e746b2413a..f8044a1169c 100644
--- a/include/asm-ia64/ia32.h
+++ b/include/asm-ia64/ia32.h
@@ -13,6 +13,8 @@
 
 # ifdef CONFIG_IA32_SUPPORT
 
+#define IA32_PAGE_OFFSET	0xc0000000
+
 extern void ia32_cpu_init (void);
 extern void ia32_mem_init (void);
 extern void ia32_gdt_init (void);