A recent change to sanitizer_common caused us to issue the syscall
madvise(MADV_HUGEPAGE) during HWASAN initialization. This may lead to a
problem if madvise is instrumented (e.g. because libc is instrumented
or the user intercepted it). For example, on Android the syscall may
fail if the kernel does not support transparent hugepages, which leads
to an attempt to set errno in a HWASAN instrumented function. Avoid
this problem by introducing a syscall wrapper and using it to issue
this syscall.
Tested only on Linux; includes untested updates for the other
platforms.
Differential Revision: https://reviews.llvm.org/D85870
`TARGET_OS_IOS` and `TARGET_OS_WATCH` are not mutually exclusive.
`SANITIZER_IOS` is defined for all embedded platforms. So the branch
for watchOS is never taken. We could fix this by switching the order
of the branches (but the reason for doing so is non-obvious). Instead,
lets use the Darwin-specific `TARGET_OS_*` macros which are mutually
exclusive.
Add a fallback for `sysctl kern.osproductversion` for XNU 17 (macOS
10.13) and below, which do not provide this property.
Unfortunately, this means we have to take the detour via Darwin kernel
version again (at least for the fallback).
Reviewed By: delcypher
Differential Revision: https://reviews.llvm.org/D84892
Checking the OS version via `GetMacosAlignedVersion()` now works in
simulators [1]. Let's use it to simplify `DyldNeedsEnvVariable()`.
[1] 3fb0de8207
Reviewed By: delcypher
Differential Revision: https://reviews.llvm.org/D81197
compiler-rt checks OS versions by querying the Darwin kernel version.
This is not necessarily correct inside the simulators if the simulator
runtime is not aligned with the host macOS. Let's instead check the
`SIMULATOR_RUNTIME_VERSION` env var.
rdar://63031937
Reviewed By: delcypher
Differential Revision: https://reviews.llvm.org/D83977
Summary:
This refactors some common support related to shadow memory setup from
asan and hwasan into sanitizer_common. This should not only reduce code
duplication but also make these facilities available for new compiler-rt
uses (e.g. heap profiling).
In most cases the separate copies of the code were either identical, or
at least functionally identical. A few notes:
In ProtectGap, the asan version checked the address against an upper
bound (kZeroBaseMaxShadowStart, which is (2^18). I have created a copy
of kZeroBaseMaxShadowStart in hwasan_mapping.h, with the same value, as
it isn't clear why that code should not do the same check. If it
shouldn't, I can remove this and guard this check so that it only
happens for asan.
In asan's InitializeShadowMemory, in the dynamic shadow case it was
setting __asan_shadow_memory_dynamic_address to 0 (which then sets both
macro SHADOW_OFFSET as well as macro kLowShadowBeg to 0) before calling
FindDynamicShadowStart(). AFAICT this is only needed because
FindDynamicShadowStart utilizes kHighShadowEnd to
get the shadow size, and kHighShadowEnd is a macro invoking
MEM_TO_SHADOW(kHighMemEnd) which in turn invokes:
(((kHighMemEnd) >> SHADOW_SCALE) + (SHADOW_OFFSET))
I.e. it computes the shadow space needed by kHighMemEnd (the shift), and
adds the offset. Since we only want the shadow space here, the earlier
setting of SHADOW_OFFSET to 0 via __asan_shadow_memory_dynamic_address
accomplishes this. In the hwasan version, it simply gets the shadow
space via "MemToShadowSize(kHighMemEnd)", where MemToShadowSize just
does the shift. I've simplified the asan handling to do the same
thing, and therefore was able to remove the setting of the SHADOW_OFFSET
via __asan_shadow_memory_dynamic_address to 0.
Reviewers: vitalybuka, kcc, eugenis
Subscribers: dberris, #sanitizers, llvm-commits, davidxl
Tags: #sanitizers
Differential Revision: https://reviews.llvm.org/D83247
compiler-rt checks OS versions by querying the Darwin kernel version.
This is not necessarily correct inside the simulators if the simulator
runtime is not aligned with the host macOS. Let's instead check the
`SIMULATOR_RUNTIME_VERSION` env var.
Note that we still use the old code path as a fallback in case the
`SIMULATOR_RUNTIME_VERSION` environment variable isn't set.
rdar://63031937
Reviewers: delcypher
Differential Revision: https://reviews.llvm.org/D79979
Support macOS 11 in our runtime version checking code and update
`GetMacosAlignedVersionInternal()` accordingly. This follows the
implementation of `Triple::getMacOSXVersion()` in the Clang driver.
Reviewed By: delcypher
Differential Revision: https://reviews.llvm.org/D82918
Use a struct to represent numerical versions instead of encoding release
names in an enumeration. This avoids the need to extend the enumeration
every time there is a new release.
Rename `GetMacosVersion() -> GetMacosAlignedVersion()` to better reflect
how this is used on non-MacOS platforms.
Reviewed By: delcypher
Differential Revision: https://reviews.llvm.org/D79970
This applies the learnings from [1]. What I intended as a simple
cleanup made me realize that the compiler-rt version checks have two
separate issues:
1) In some places (e.g., mmap flag setting) what matters is the kernel
version, not the OS version.
2) OS version checks are implemented by querying the kernel version.
This is not necessarily correct inside the simulators if the
simulator runtime isn't aligned with the host macOS.
This commit tackles 1) by adopting a separate query function for the
Darwin kernel version. 2) (and cleanups) will be dealt with in
follow-ups.
[1] https://reviews.llvm.org/D78942
rdar://63031937
Reviewed By: delcypher
Differential Revision: https://reviews.llvm.org/D79965
Create a sanitizer_ptrauth.h header that #includes <ptrauth> when
available and defines just the required macros as "no ops" otherwise.
This should avoid the need for excessive #ifdef'ing.
Follow-up to and discussed in: https://reviews.llvm.org/D79132
Reviewed By: delcypher
Differential Revision: https://reviews.llvm.org/D79540
When reporting diagnostics from ASan's (and other sanitizer's) signal
handlers we should strip the "invalid signature" bit before printing
addresses. This makes the report less confusing and let's the user
focus on the real issue.
rdar://62615826
Reviewed By: kubamracek, delcypher
Differential Revision: https://reviews.llvm.org/D79132
Newer iOS SDK introduce accessors to retrieve the register values
(arm_thread_state64_get_*) and disallows direct access to fields. If
arm_thread_state64_get_sp is defined, the accessors are available.
Summary:
This change introduces the `Symbolizer::GetEnvP()` method that returns a
pointer to environment array used for spawning the symbolizer process.
The motivation is to allow implementations to customise the environment
if required. The default implementation just returns
`__sanitizer::GetEnviron()` which (provided it's implemented) should
preserve the existing behaviours of the various implementations.
This change has been plumbed through the `internal_spawn(...)` and
`StartSubprocess(...)` process spawning implementations.
For the `StartSubprocess()` implementation we need to call `execve()`
rather than `execv()` to pass the environment. However, it appears that
`internal_execve(...)` exists in sanitizer_common so this patch use that
which seems like a nice clean up.
Support in the Windows implementation of
`SymbolizerProcess:StartSymbolizerSubprocess()` has not been added
because the Windows sanitizer runtime doesn't implement `GetEnviron()`.
rdar://problem/58789439
Reviewers: kubamracek, yln, dvyukov, vitalybuka, eugenis, phosek, aizatsky, rnk
Subscribers: #sanitizers, llvm-commits
Tags: #sanitizers
Differential Revision: https://reviews.llvm.org/D76666
Summary:
Instead of hand-crafting an offset into the structure returned by
dlopen(3) to get at the link map, use the documented API. This is
described in dlinfo(3): by calling it with `RTLD_DI_LINKMAP`, the
dynamic linker ensures the right address is returned.
This is a recommit of 92e267a94d, with
dlinfo(3) expliclity being referenced only for FreeBSD, non-Android
Linux, NetBSD and Solaris. Other OSes will have to add their own
implementation.
Reviewers: devnexen, emaste, MaskRay, krytarowski
Reviewed By: krytarowski
Subscribers: krytarowski, vitalybuka, #sanitizers, llvm-commits
Tags: #sanitizers, #llvm
Differential Revision: https://reviews.llvm.org/D73990
Summary:
Instead of hand-crafting an offset into the structure returned by
dlopen(3) to get at the link map, use the documented API. This is
described in dlinfo(3): by calling it with `RTLD_DI_LINKMAP`, the
dynamic linker ensures the right address is returned.
Reviewers: devnexen, emaste, MaskRay, krytarowski
Reviewed By: krytarowski
Subscribers: krytarowski, vitalybuka, #sanitizers, llvm-commits
Tags: #sanitizers, #llvm
Differential Revision: https://reviews.llvm.org/D73990
Updated: Removed offending TODO comment.
Dereferences with addresses above the 48-bit hardware addressable range
produce "invalid instruction" (instead of "invalid access") hardware
exceptions (there is no hardware address decoding logic for those bits),
and the address provided by this exception is the address of the
instruction (not the faulting address). The kernel maps the "invalid
instruction" to SEGV, but fails to provide the real fault address.
Because of this ASan lies and says that those cases are null
dereferences. This downgrades the severity of a found bug in terms of
security. In the ASan signal handler, we can not provide the real
faulting address, but at least we can try not to lie.
rdar://50366151
Reviewed By: vitalybuka
Differential Revision: https://reviews.llvm.org/D68676
> llvm-svn: 374265
llvm-svn: 374384
Dereferences with addresses above the 48-bit hardware addressable range
produce "invalid instruction" (instead of "invalid access") hardware
exceptions (there is no hardware address decoding logic for those bits),
and the address provided by this exception is the address of the
instruction (not the faulting address). The kernel maps the "invalid
instruction" to SEGV, but fails to provide the real fault address.
Because of this ASan lies and says that those cases are null
dereferences. This downgrades the severity of a found bug in terms of
security. In the ASan signal handler, we can not provide the real
faulting address, but at least we can try not to lie.
rdar://50366151
Reviewed By: vitalybuka
Differential Revision: https://reviews.llvm.org/D68676
llvm-svn: 374265
Use attribute flag `POSIX_SPAWN_CLOEXEC_DEFAULT` in the call to
`posix_spawn`.
If this flag is set, then only file descriptors explicitly described by
the file_actions argument are available in the spawned process; all of
the other file descriptors are automatically closed in the spawned
process.
POSIX_SPAWN_CLOEXEC_DEFAULT is an Apple-specific extension.
llvm-svn: 370121
On Darwin, we currently use forkpty to communicate with the "atos"
symbolizer. There are several problems that fork[pty] has, e.g. that
after fork, interceptors are still active and this sometimes causes
crashes or hangs. This is especially problematic for TSan, which uses
interceptors for OS-provided locks and mutexes, and even Libc functions
use those.
This patch replaces forkpty with posix_spawn on Darwin. Since
posix_spawn doesn't fork (at least on Darwin), the interceptors are not
a problem. Another benefit is that we'll handle post-fork failures (e.g.
sandbox disallows "exec") gracefully now.
Related revisions and previous attempts that were blocked by or had to
be revered due to test failures:
https://reviews.llvm.org/D48451https://reviews.llvm.org/D40032
Reviewed By: kubamracek
Differential Revision: https://reviews.llvm.org/D65253
llvm-svn: 368947
See https://reviews.llvm.org/D58620 for discussion, and for the commands
I ran. In addition I also ran
for f in $(svn diff | diffstat | grep .cc | cut -f 2 -d ' '); do rg $f . ; done
and manually updated (many) references to renamed files found by that.
llvm-svn: 367463
Peter Collingbourne