Attachment 199401 Details for Bug 294541 – Andis proposed patch

[patch] Andis proposed patch

1.txt (text/plain), 3.15 KB, created by Mark J. Cox on 2007-09-19 10:51:23 UTC

(hide)

Description:

Filename:

MIME Type:

Creator: Mark J. Cox

Created: 2007-09-19 10:51:23 UTC

Size: 3.15 KB

patch

obsolete

>Zero extend eax after ptrace in 32bit entry path.
>It actually does a little more than strictly needed -- the other registers are 
>already zero extended.
>
>Signed-off-by: Andi Kleen <ak@suse.de>
>
>Index: linux/arch/x86_64/ia32/ia32entry.S
>===================================================================
>--- linux.orig/arch/x86_64/ia32/ia32entry.S
>+++ linux/arch/x86_64/ia32/ia32entry.S
>@@ -38,6 +38,18 @@
> 	movq	%rax,R8(%rsp)
> 	.endm
> 
>+	.macro LOAD_ARGS32 offset
>+	movl \offset(%rsp),%r11d
>+	movl \offset+8(%rsp),%r10d
>+	movl \offset+16(%rsp),%r9d
>+	movl \offset+24(%rsp),%r8d
>+	movl \offset+40(%rsp),%ecx
>+	movl \offset+48(%rsp),%edx
>+	movl \offset+56(%rsp),%esi
>+	movl \offset+64(%rsp),%edi
>+	movl \offset+72(%rsp),%eax
>+	.endm
>+	
> 	.macro CFI_STARTPROC32 simple
> 	CFI_STARTPROC	\simple
> 	CFI_UNDEFINED	r8
>@@ -152,7 +164,7 @@ sysenter_tracesys:
> 	movq	$-ENOSYS,RAX(%rsp)	/* really needed? */
> 	movq	%rsp,%rdi        /* &pt_regs -> arg1 */
> 	call	syscall_trace_enter
>-	LOAD_ARGS ARGOFFSET  /* reload args from stack in case ptrace changed it */
>+	LOAD_ARGS32 ARGOFFSET  /* reload args from stack in case ptrace changed it 
>*/
> 	RESTORE_REST
> 	movl	%ebp, %ebp
> 	/* no need to do an access_ok check here because rbp has been
>@@ -255,7 +267,7 @@ cstar_tracesys:	
> 	movq $-ENOSYS,RAX(%rsp)	/* really needed? */
> 	movq %rsp,%rdi        /* &pt_regs -> arg1 */
> 	call syscall_trace_enter
>-	LOAD_ARGS ARGOFFSET  /* reload args from stack in case ptrace changed it */
>+	LOAD_ARGS32 ARGOFFSET  /* reload args from stack in case ptrace changed it 
>*/
> 	RESTORE_REST
> 	movl RSP-ARGOFFSET(%rsp), %r8d
> 	/* no need to do an access_ok check here because r8 has been
>@@ -334,7 +346,7 @@ ia32_tracesys:			 
> 	movq $-ENOSYS,RAX(%rsp)	/* really needed? */
> 	movq %rsp,%rdi        /* &pt_regs -> arg1 */
> 	call syscall_trace_enter
>-	LOAD_ARGS ARGOFFSET  /* reload args from stack in case ptrace changed it */
>+	LOAD_ARGS32 ARGOFFSET  /* reload args from stack in case ptrace changed it 
>*/
> 	RESTORE_REST
> 	jmp ia32_do_syscall
> END(ia32_syscall)
>Index: linux/arch/x86_64/kernel/ptrace.c
>===================================================================
>--- linux.orig/arch/x86_64/kernel/ptrace.c
>+++ linux/arch/x86_64/kernel/ptrace.c
>@@ -232,10 +232,6 @@ static int putreg(struct task_struct *ch
> {
> 	unsigned long tmp; 
> 	
>-	/* Some code in the 64bit emulation may not be 64bit clean.
>-	   Don't take any chances. */
>-	if (test_tsk_thread_flag(child, TIF_IA32))
>-		value &= 0xffffffff;
> 	switch (regno) {
> 		case offsetof(struct user_regs_struct,fs):
> 			if (value && (value & 3) != 3)
>
>
>----------------------------------------------
>
>2.4 patch
>
>Make sure to validate all 64bits of ptrace information
>
>Signed-off-by: Andi Kleen <ak@suse.de>
>
>Index: linux-2.4.33/arch/x86_64/ia32/ia32entry.S
>===================================================================
>--- linux-2.4.33.orig/arch/x86_64/ia32/ia32entry.S
>+++ linux-2.4.33/arch/x86_64/ia32/ia32entry.S
>@@ -73,7 +73,7 @@ ia32_tracesys:			 
> 	call syscall_trace
> 	LOAD_ARGS ARGOFFSET  /* reload args from stack in case ptrace changed it */
> 	RESTORE_REST
>-	cmpl $(IA32_NR_syscalls),%eax
>+	cmpq $(IA32_NR_syscalls),%rax
> 	jae  1f
> 	IA32_ARG_FIXUP
> 	call *ia32_sys_call_table(,%rax,8)
>
>

Actions: View | Diff

Attachments on bug 294541: 199401