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| author | Mathieu Desnoyers <mathieu.desnoyers@efficios.com> | 2022-01-24 20:12:43 +0300 |
|---|---|---|
| committer | Peter Zijlstra <peterz@infradead.org> | 2022-02-02 15:11:35 +0300 |
| commit | e546cd48ccc456074ddb8920732aef4af65d7ca7 (patch) | |
| tree | e9ca24ec796e1635c74982918b875776e19c5aee /tools/testing/selftests/rseq/rseq.h | |
| parent | 94b80a19ebfe347a01301d750040a61c38200e2b (diff) | |
| download | linux-e546cd48ccc456074ddb8920732aef4af65d7ca7.tar.xz | |
selftests/rseq: Introduce rseq_get_abi() helper
This is done in preparation for the selftest uplift to become compatible
with glibc-2.35.
glibc-2.35 exposes the rseq per-thread data in the TCB, accessible
at an offset from the thread pointer, rather than through an actual
Thread-Local Storage (TLS) variable, as the kernel selftests initially
expected.
Introduce a rseq_get_abi() helper, initially using the __rseq_abi
TLS variable, in preparation for changing this userspace ABI for one
which is compatible with glibc-2.35.
Note that the __rseq_abi TLS and glibc-2.35's ABI for per-thread data
cannot actively coexist in a process, because the kernel supports only
a single rseq registration per thread.
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20220124171253.22072-6-mathieu.desnoyers@efficios.com
Diffstat (limited to 'tools/testing/selftests/rseq/rseq.h')
| -rw-r--r-- | tools/testing/selftests/rseq/rseq.h | 11 |
1 files changed, 8 insertions, 3 deletions
diff --git a/tools/testing/selftests/rseq/rseq.h b/tools/testing/selftests/rseq/rseq.h index d580f8e9c001..ca668a2af172 100644 --- a/tools/testing/selftests/rseq/rseq.h +++ b/tools/testing/selftests/rseq/rseq.h @@ -46,6 +46,11 @@ extern __thread struct rseq_abi __rseq_abi; extern int __rseq_handled; +static inline struct rseq_abi *rseq_get_abi(void) +{ + return &__rseq_abi; +} + #define rseq_likely(x) __builtin_expect(!!(x), 1) #define rseq_unlikely(x) __builtin_expect(!!(x), 0) #define rseq_barrier() __asm__ __volatile__("" : : : "memory") @@ -108,7 +113,7 @@ int32_t rseq_fallback_current_cpu(void); */ static inline int32_t rseq_current_cpu_raw(void) { - return RSEQ_ACCESS_ONCE(__rseq_abi.cpu_id); + return RSEQ_ACCESS_ONCE(rseq_get_abi()->cpu_id); } /* @@ -124,7 +129,7 @@ static inline int32_t rseq_current_cpu_raw(void) */ static inline uint32_t rseq_cpu_start(void) { - return RSEQ_ACCESS_ONCE(__rseq_abi.cpu_id_start); + return RSEQ_ACCESS_ONCE(rseq_get_abi()->cpu_id_start); } static inline uint32_t rseq_current_cpu(void) @@ -139,7 +144,7 @@ static inline uint32_t rseq_current_cpu(void) static inline void rseq_clear_rseq_cs(void) { - RSEQ_WRITE_ONCE(__rseq_abi.rseq_cs.arch.ptr, 0); + RSEQ_WRITE_ONCE(rseq_get_abi()->rseq_cs.arch.ptr, 0); } /* |