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authorEric Paris <eparis@redhat.com>2012-01-03 20:23:06 +0100
committerAl Viro <viro@zeniv.linux.org.uk>2012-01-17 22:16:56 +0100
commitf031cd25568a390dc2c9c3a4015054183753449a (patch)
treeb837ca821ea5138af2f80400afb2175fa68763f2
parentAudit: push audit success and retcode into arch ptrace.h (diff)
downloadlinux-f031cd25568a390dc2c9c3a4015054183753449a.tar.xz
linux-f031cd25568a390dc2c9c3a4015054183753449a.zip
audit: ia32entry.S sign extend error codes when calling 64 bit code
In the ia32entry syscall exit audit fastpath we have assembly code which calls __audit_syscall_exit directly. This code was, however, zeroes the upper 32 bits of the return code. It then proceeded to call code which expects longs to be 64bits long. In order to handle code which expects longs to be 64bit we sign extend the return code if that code is an error. Thus the __audit_syscall_exit function can correctly handle using the values in snprintf("%ld"). This fixes the regression introduced in 5cbf1565f29eb57a86a. Old record: type=SYSCALL msg=audit(1306197182.256:281): arch=40000003 syscall=192 success=no exit=4294967283 New record: type=SYSCALL msg=audit(1306197182.256:281): arch=40000003 syscall=192 success=no exit=-13 Signed-off-by: Eric Paris <eparis@redhat.com> Acked-by: H. Peter Anvin <hpa@zytor.com>
-rw-r--r--arch/x86/ia32/ia32entry.S4
1 files changed, 3 insertions, 1 deletions
diff --git a/arch/x86/ia32/ia32entry.S b/arch/x86/ia32/ia32entry.S
index 64ced0b8f8fd..025f0f01d254 100644
--- a/arch/x86/ia32/ia32entry.S
+++ b/arch/x86/ia32/ia32entry.S
@@ -210,7 +210,9 @@ sysexit_from_sys_call:
sti
movl %eax,%esi /* second arg, syscall return value */
cmpl $-MAX_ERRNO,%eax /* is it an error ? */
- setbe %al /* 1 if so, 0 if not */
+ jbe 1f
+ movslq %eax, %rsi /* if error sign extend to 64 bits */
+1: setbe %al /* 1 if error, 0 if not */
movzbl %al,%edi /* zero-extend that into %edi */
call __audit_syscall_exit
movq RAX-ARGOFFSET(%rsp),%rax /* reload syscall return value */