Commit bd1d6e24 authored by Robin Holt's avatar Robin Holt Committed by Tony Luck
Browse files

[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: default avatarRobin Holt <holt@sgi.com>
Signed-off-by: default avatarTony Luck <tony.luck@intel.com>
parent acb7f672

arch/ia64/ia32/binfmt_elf32.c

+0 −2
Original line number Diff line number Diff line
@@ -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

arch/ia64/ia32/ia32priv.h

+0 −1
Original line number Diff line number Diff line
@@ -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

arch/ia64/kernel/process.c

+4 −1
Original line number Diff line number Diff line
@@ -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);

	}

}



/*

include/asm-ia64/ia32.h

+2 −0
Original line number Diff line number Diff line
@@ -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);

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