Introduce the -msan-kernel flag, which enables the kernel instrumentation.
The main differences between KMSAN and MSan instrumentations are:
- KMSAN implies msan-track-origins=2, msan-keep-going=true;
- there're no explicit accesses to shadow and origin memory.
Shadow and origin values for a particular X-byte memory location are
read and written via pointers returned by
__msan_metadata_ptr_for_load_X(u8 *addr) and
__msan_store_shadow_origin_X(u8 *addr, uptr shadow, uptr origin);
- TLS variables are stored in a single struct in per-task storage. A call
to a function returning that struct is inserted into every instrumented
function before the entry block;
- __msan_warning() takes a 32-bit origin parameter;
- local variables are poisoned with __msan_poison_alloca() upon function
entry and unpoisoned with __msan_unpoison_alloca() before leaving the
function;
- the pass doesn't declare any global variables or add global constructors
to the translation unit.
llvm-svn: 341637
Add the __msan_va_arg_origin_tls TLS array to keep the origins for variadic function parameters.
Change the instrumentation pass to store parameter origins in this array.
This is a reland of r341528.
test/msan/vararg.cc doesn't work on Mips, PPC and AArch64 (because this
patch doesn't touch them), XFAIL these arches.
Also turned out Clang crashed on i80 vararg arguments because of
incorrect origin type returned by getOriginPtrForVAArgument() - fixed it
and added a test.
llvm-svn: 341554
Add the __msan_va_arg_origin_tls TLS array to keep the origins for
variadic function parameters.
Change the instrumentation pass to store parameter origins in this array.
llvm-svn: 341528
Turns out that calling a variadic function with too many (e.g. >100 i64's)
arguments overflows __msan_va_arg_tls, which leads to smashing other TLS
data with function argument shadow values.
getShadow() already checks for kParamTLSSize and returns clean shadow if
the argument does not fit, so just skip storing argument shadow for such
arguments.
llvm-svn: 341525
If code is compiled for X86 without SSE support, the register save area
doesn't contain FPU registers, so `AMD64FpEndOffset` should be equal to
`AMD64GpEndOffset`.
llvm-svn: 339414
When pointer checking is enabled, it's important that every pointer is
checked before its value is used.
For stores MSan used to generate code that calculates shadow/origin
addresses from a pointer before checking it.
For userspace this isn't a problem, because the shadow calculation code
is quite simple and compiler is able to move it after the check on -O2.
But for KMSAN getShadowOriginPtr() creates a runtime call, so we want the
check to be performed strictly before that call.
Swapping materializeChecks() and materializeStores() resolves the issue:
both functions insert code before the given IR location, so the new
insertion order guarantees that the code calculating shadow address is
between the address check and the memory access.
llvm-svn: 337571
See https://reviews.llvm.org/D47106 for details.
Reviewed By: probinson
Differential Revision: https://reviews.llvm.org/D47171
This commit drops that patch's changes to:
llvm/test/CodeGen/NVPTX/f16x2-instructions.ll
llvm/test/CodeGen/NVPTX/param-load-store.ll
For some reason, the dos line endings there prevent me from commiting
via the monorepo. A follow-up commit (not via the monorepo) will
finish the patch.
llvm-svn: 336843
Summary:
Floating point division by zero or even undef does not have undefined
behavior and may occur due to optimizations.
Fixes https://bugs.llvm.org/show_bug.cgi?id=37523.
Reviewers: kcc
Subscribers: hiraditya, llvm-commits
Differential Revision: https://reviews.llvm.org/D47085
llvm-svn: 332761
In order to set breakpoints on labels and list source code around
labels, we need collect debug information for labels, i.e., label
name, the function label belong, line number in the file, and the
address label located. In order to keep these information in LLVM
IR and to allow backend to generate debug information correctly.
We create a new kind of metadata for labels, DILabel. The format
of DILabel is
!DILabel(scope: !1, name: "foo", file: !2, line: 3)
We hope to keep debug information as much as possible even the
code is optimized. So, we create a new kind of intrinsic for label
metadata to avoid the metadata is eliminated with basic block.
The intrinsic will keep existing if we keep it from optimized out.
The format of the intrinsic is
llvm.dbg.label(metadata !1)
It has only one argument, that is the DILabel metadata. The
intrinsic will follow the label immediately. Backend could get the
label metadata through the intrinsic's parameter.
We also create DIBuilder API for labels to be used by Frontend.
Frontend could use createLabel() to allocate DILabel objects, and use
insertLabel() to insert llvm.dbg.label intrinsic in LLVM IR.
Differential Revision: https://reviews.llvm.org/D45024
Patch by Hsiangkai Wang.
llvm-svn: 331841
This is the patch that lowers x86 intrinsics to native IR
in order to enable optimizations. The patch also includes folding
of previously missing saturation patterns so that IR emits the same
machine instructions as the intrinsics.
Patch by tkrupa
Differential Revision: https://reviews.llvm.org/D44785
llvm-svn: 330322
The default assembly handling mode may introduce false positives in the
cases when MSan doesn't understand that the assembly call initializes
the memory pointed to by one of its arguments.
We introduce the conservative mode, which initializes the first
|sizeof(type)| bytes for every |type*| pointer passed into the
assembly statement.
llvm-svn: 329054
MSan used to insert the shadow check of the store pointer operand
_after_ the shadow of the value operand has been written.
This happens to work in the userspace, as the whole shadow range is
always mapped. However in the kernel the shadow page may not exist, so
the bug may cause a crash.
This patch moves the address check in front of the shadow access.
llvm-svn: 318901
Summary:
Add canary tests to verify that MSAN currently does nothing with the element atomic memory intrinsics for memcpy, memmove, and memset.
Placeholder tests that will fail once element atomic @llvm.mem[cpy|move|set] instrinsics have been added to the MemIntrinsic class hierarchy. These will act as a reminder to verify that MSAN handles these intrinsics properly once they have been added to that class hierarchy.
Reviewers: reames
Reviewed By: reames
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D35510
llvm-svn: 308251
It turned out that MSan was incorrectly calculating the shadow for int comparisons: it was done by truncating the result of (Shadow1 OR Shadow2) to i1, effectively rendering all bits except LSB useless.
This approach doesn't work e.g. in the case where the values being compared are even (i.e. have the LSB of the shadow equal to zero).
Instead, if CreateShadowCast() has to cast a bigger int to i1, we replace the truncation with an ICMP to 0.
This patch doesn't affect the code generated for SPEC 2006 binaries, i.e. there's no performance impact.
For the test case reported in PR32842 MSan with the patch generates a slightly more efficient code:
orq %rcx, %rax
jne .LBB0_6
, instead of:
orl %ecx, %eax
testb $1, %al
jne .LBB0_6
llvm-svn: 302787
Fix incorrect calculation of the type size for __msan_maybe_warning_N
call that resulted in an invalid (narrowing) zext instruction and
"Assertion `castIsValid(op, S, Ty) && "Invalid cast!"' failed."
Only happens in very large functions (with more than 3500 MSan
checks) operating on integer types that are not power-of-two.
llvm-svn: 274395
CodeGen has hooks that allow targets to emit specialized code instead
of calls to memcmp, memchr, strcpy, stpcpy, strcmp, strlen, strnlen.
When ASan/MSan/TSan/ESan is in use, this sidesteps its interceptors, resulting
in uninstrumented memory accesses. To avoid that, make these sanitizers
mark the calls as nobuiltin.
Differential Revision: http://reviews.llvm.org/D19781
llvm-svn: 273083
This fixes http://llvm.org/PR27646 on AArch64.
There are three issues here:
- The GR save area is 7 words in size, instead of 8. This is not enough
if none of the fixed arguments is passed in GRs (they're all floats or
aggregates).
- The first argument is ignored (which counteracts the above if it's passed
in GR).
- Like x86_64, fixed arguments landing in the overflow area are wrongly
counted towards the overflow offset.
Differential Revision: http://reviews.llvm.org/D20023
llvm-svn: 268967
Currently each Function points to a DISubprogram and DISubprogram has a
scope field. For member functions the scope is a DICompositeType. DIScopes
point to the DICompileUnit to facilitate type uniquing.
Distinct DISubprograms (with isDefinition: true) are not part of the type
hierarchy and cannot be uniqued. This change removes the subprograms
list from DICompileUnit and instead adds a pointer to the owning compile
unit to distinct DISubprograms. This would make it easy for ThinLTO to
strip unneeded DISubprograms and their transitively referenced debug info.
Motivation
----------
Materializing DISubprograms is currently the most expensive operation when
doing a ThinLTO build of clang.
We want the DISubprogram to be stored in a separate Bitcode block (or the
same block as the function body) so we can avoid having to expensively
deserialize all DISubprograms together with the global metadata. If a
function has been inlined into another subprogram we need to store a
reference the block containing the inlined subprogram.
Attached to https://llvm.org/bugs/show_bug.cgi?id=27284 is a python script
that updates LLVM IR testcases to the new format.
http://reviews.llvm.org/D19034
<rdar://problem/25256815>
llvm-svn: 266446
There is something strange going on with debug info (.eh_frame_hdr)
disappearing when msan.module_ctor are placed in comdat sections.
Moving this functionality under flag, disabled by default.
llvm-svn: 263579
MSan adds a constructor to each translation unit that calls
__msan_init, and does nothing else. The idea is to run __msan_init
before any instrumented code. This results in multiple constructors
and multiple .init_array entries in the final binary, one per
translation unit. This is absolutely unnecessary; one would be
enough.
This change moves the constructors to a comdat group in order to drop
the extra ones.
llvm-svn: 260632
This patch fixes the memory sanitizer origin store instrumentation for
array types. This can be triggered by cases where frontend lowers
function return to array type instead of aggregation.
For instance, the C code:
--
struct mypair {
int64_t x;
int y;
};
mypair my_make_pair(int64_t x, int y) {
mypair p;
p.x = x;
p.y = y;
return p;
}
int foo (int p)
{
mypair z = my_make_pair(p, 0);
return z.y + z.x;
}
--
It will be lowered with target set to aarch64-linux and -O0 to:
--
[...]
define i32 @_Z3fooi(i32 %p) #0 {
[...]
%call = call [2 x i64] @_Z12my_make_pairxi(i64 %conv, i32 0)
%1 = bitcast %struct.mypair* %z to [2 x i64]*
store [2 x i64] %call, [2 x i64]* %1, align 8
[...]
--
The origin store will emit a 'icmp' to test each store value again the
TLS origin array. However since 'icmp' does not support ArrayType the
memory instrumentation phase will bail out with an error.
This patch change it by using the same strategy used for struct type on
array.
It fixes the 'test/msan/insertvalue_origin.cc' for aarch64 (the -O0 case).
llvm-svn: 257375
This patch add support for variadic argument for AArch64. All the MSAN
unit tests are not passing as well the signal_stress_test (currently
set as XFAIl for aarch64).
llvm-svn: 255495
Change origin-alignment test to test only the alignment of the origin
store, and not the exact instruction sequence used to compute the
address. This makes the test less fragile and, in particular, lets it
pass both with the old and new MSan ABIs.
llvm-svn: 254027