b7926ce6d7
It's currently ambiguous in IR whether the source language explicitly did not want a stack a stack protector (in C, via function attribute no_stack_protector) or doesn't care for any given function. It's common for code that manipulates the stack via inline assembly or that has to set up its own stack canary (such as the Linux kernel) would like to avoid stack protectors in certain functions. In this case, we've been bitten by numerous bugs where a callee with a stack protector is inlined into an __attribute__((__no_stack_protector__)) caller, which generally breaks the caller's assumptions about not having a stack protector. LTO exacerbates the issue. While developers can avoid this by putting all no_stack_protector functions in one translation unit together and compiling those with -fno-stack-protector, it's generally not very ergonomic or as ergonomic as a function attribute, and still doesn't work for LTO. See also: https://lore.kernel.org/linux-pm/20200915172658.1432732-1-rkir@google.com/ https://lore.kernel.org/lkml/20200918201436.2932360-30-samitolvanen@google.com/T/#u Typically, when inlining a callee into a caller, the caller will be upgraded in its level of stack protection (see adjustCallerSSPLevel()). By adding an explicit attribute in the IR when the function attribute is used in the source language, we can now identify such cases and prevent inlining. Block inlining when the callee and caller differ in the case that one contains `nossp` when the other has `ssp`, `sspstrong`, or `sspreq`. Fixes pr/47479. Reviewed By: void Differential Revision: https://reviews.llvm.org/D87956
166 lines
4.2 KiB
LLVM
166 lines
4.2 KiB
LLVM
; RUN: opt -inline %s -S | FileCheck %s
|
|
; RUN: opt -passes='cgscc(inline)' %s -S | FileCheck %s
|
|
; Ensure SSP attributes are propagated correctly when inlining.
|
|
; This test case covers callers that are unspecified in their level of stack
|
|
; protection. See also llvm/test/Transforms/Inline/inline_nossp.ll
|
|
; which tests callers with ``nossp`` function attribute which is stack
|
|
; protection explicitly disabled.
|
|
|
|
@.str = private unnamed_addr constant [11 x i8] c"fun_nossp\0A\00", align 1
|
|
@.str1 = private unnamed_addr constant [9 x i8] c"fun_ssp\0A\00", align 1
|
|
@.str2 = private unnamed_addr constant [15 x i8] c"fun_sspstrong\0A\00", align 1
|
|
@.str3 = private unnamed_addr constant [12 x i8] c"fun_sspreq\0A\00", align 1
|
|
|
|
; These first four functions (@fun_sspreq, @fun_sspstrong, @fun_ssp, @fun_nossp)
|
|
; are used by the remaining functions to ensure that the SSP attributes are
|
|
; propagated correctly. The caller should have its SSP attribute set as:
|
|
; strictest(caller-ssp-attr, callee-ssp-attr), where strictness is ordered as:
|
|
; sspreq > sspstrong > ssp > [no ssp]
|
|
define internal void @fun_sspreq() nounwind sspreq uwtable {
|
|
entry:
|
|
%call = call i32 (i8*, ...) @printf(i8* getelementptr inbounds ([12 x i8], [12 x i8]* @.str3, i32 0, i32 0))
|
|
ret void
|
|
}
|
|
|
|
define internal void @fun_sspstrong() nounwind sspstrong uwtable {
|
|
entry:
|
|
%call = call i32 (i8*, ...) @printf(i8* getelementptr inbounds ([15 x i8], [15 x i8]* @.str2, i32 0, i32 0))
|
|
ret void
|
|
}
|
|
|
|
define internal void @fun_ssp() nounwind ssp uwtable {
|
|
entry:
|
|
%call = call i32 (i8*, ...) @printf(i8* getelementptr inbounds ([9 x i8], [9 x i8]* @.str1, i32 0, i32 0))
|
|
ret void
|
|
}
|
|
|
|
define internal void @fun_nossp() nounwind uwtable {
|
|
entry:
|
|
%call = call i32 (i8*, ...) @printf(i8* getelementptr inbounds ([11 x i8], [11 x i8]* @.str, i32 0, i32 0))
|
|
ret void
|
|
}
|
|
|
|
; Tests start below
|
|
|
|
define void @inline_req_req() nounwind sspreq uwtable {
|
|
entry:
|
|
; CHECK: @inline_req_req() #0
|
|
call void @fun_sspreq()
|
|
ret void
|
|
}
|
|
|
|
define void @inline_req_strong() nounwind sspstrong uwtable {
|
|
entry:
|
|
; CHECK: @inline_req_strong() #0
|
|
call void @fun_sspreq()
|
|
ret void
|
|
}
|
|
|
|
define void @inline_req_ssp() nounwind ssp uwtable {
|
|
entry:
|
|
; CHECK: @inline_req_ssp() #0
|
|
call void @fun_sspreq()
|
|
ret void
|
|
}
|
|
|
|
define void @inline_req_nossp() nounwind uwtable {
|
|
entry:
|
|
; CHECK: @inline_req_nossp() #0
|
|
call void @fun_sspreq()
|
|
ret void
|
|
}
|
|
|
|
define void @inline_strong_req() nounwind sspreq uwtable {
|
|
entry:
|
|
; CHECK: @inline_strong_req() #0
|
|
call void @fun_sspstrong()
|
|
ret void
|
|
}
|
|
|
|
|
|
define void @inline_strong_strong() nounwind sspstrong uwtable {
|
|
entry:
|
|
; CHECK: @inline_strong_strong() #1
|
|
call void @fun_sspstrong()
|
|
ret void
|
|
}
|
|
|
|
define void @inline_strong_ssp() nounwind ssp uwtable {
|
|
entry:
|
|
; CHECK: @inline_strong_ssp() #1
|
|
call void @fun_sspstrong()
|
|
ret void
|
|
}
|
|
|
|
define void @inline_strong_nossp() nounwind uwtable {
|
|
entry:
|
|
; CHECK: @inline_strong_nossp() #1
|
|
call void @fun_sspstrong()
|
|
ret void
|
|
}
|
|
|
|
define void @inline_ssp_req() nounwind sspreq uwtable {
|
|
entry:
|
|
; CHECK: @inline_ssp_req() #0
|
|
call void @fun_ssp()
|
|
ret void
|
|
}
|
|
|
|
|
|
define void @inline_ssp_strong() nounwind sspstrong uwtable {
|
|
entry:
|
|
; CHECK: @inline_ssp_strong() #1
|
|
call void @fun_ssp()
|
|
ret void
|
|
}
|
|
|
|
define void @inline_ssp_ssp() nounwind ssp uwtable {
|
|
entry:
|
|
; CHECK: @inline_ssp_ssp() #2
|
|
call void @fun_ssp()
|
|
ret void
|
|
}
|
|
|
|
define void @inline_ssp_nossp() nounwind uwtable {
|
|
entry:
|
|
; CHECK: @inline_ssp_nossp() #2
|
|
call void @fun_ssp()
|
|
ret void
|
|
}
|
|
|
|
define void @inline_nossp_req() nounwind uwtable sspreq {
|
|
entry:
|
|
; CHECK: @inline_nossp_req() #0
|
|
call void @fun_nossp()
|
|
ret void
|
|
}
|
|
|
|
|
|
define void @inline_nossp_strong() nounwind sspstrong uwtable {
|
|
entry:
|
|
; CHECK: @inline_nossp_strong() #1
|
|
call void @fun_nossp()
|
|
ret void
|
|
}
|
|
|
|
define void @inline_nossp_ssp() nounwind ssp uwtable {
|
|
entry:
|
|
; CHECK: @inline_nossp_ssp() #2
|
|
call void @fun_nossp()
|
|
ret void
|
|
}
|
|
|
|
define void @inline_nossp_nossp() nounwind uwtable {
|
|
entry:
|
|
; CHECK: @inline_nossp_nossp() #3
|
|
call void @fun_nossp()
|
|
ret void
|
|
}
|
|
|
|
declare i32 @printf(i8*, ...)
|
|
|
|
; CHECK: attributes #0 = { nounwind sspreq uwtable }
|
|
; CHECK: attributes #1 = { nounwind sspstrong uwtable }
|
|
; CHECK: attributes #2 = { nounwind ssp uwtable }
|
|
; CHECK: attributes #3 = { nounwind uwtable }
|