diff options
| author | Peter Maydell <peter.maydell@linaro.org> | 2019-01-29 11:46:04 +0000 |
|---|---|---|
| committer | Peter Maydell <peter.maydell@linaro.org> | 2019-01-29 11:46:04 +0000 |
| commit | f454a54f3bf95920d236ad893344141085db061a (patch) | |
| tree | 041a9d9d82141804b74a61088960dfc37452a640 /accel | |
| parent | ea7a5330b79523540ba776c529b09dc8cf3fa0c5 (diff) | |
accel/tcg/user-exec: Don't parse aarch64 insns to test for read vs write
In cpu_signal_handler() for aarch64 hosts, currently we parse
the faulting instruction to see if it is a load or a store.
Since the 3.16 kernel (~2014), the kernel has provided us with
the syndrome register for a fault, which includes the WnR bit.
Use this instead if it is present, only falling back to
instruction parsing if not.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20190108180014.32386-1-peter.maydell@linaro.org
Diffstat (limited to 'accel')
| -rw-r--r-- | accel/tcg/user-exec.c | 66 |
1 files changed, 52 insertions, 14 deletions
diff --git a/accel/tcg/user-exec.c b/accel/tcg/user-exec.c index 941295ea49..66cc818e3f 100644 --- a/accel/tcg/user-exec.c +++ b/accel/tcg/user-exec.c @@ -479,28 +479,66 @@ int cpu_signal_handler(int host_signum, void *pinfo, #elif defined(__aarch64__) +#ifndef ESR_MAGIC +/* Pre-3.16 kernel headers don't have these, so provide fallback definitions */ +#define ESR_MAGIC 0x45535201 +struct esr_context { + struct _aarch64_ctx head; + uint64_t esr; +}; +#endif + +static inline struct _aarch64_ctx *first_ctx(ucontext_t *uc) +{ + return (struct _aarch64_ctx *)&uc->uc_mcontext.__reserved; +} + +static inline struct _aarch64_ctx *next_ctx(struct _aarch64_ctx *hdr) +{ + return (struct _aarch64_ctx *)((char *)hdr + hdr->size); +} + int cpu_signal_handler(int host_signum, void *pinfo, void *puc) { siginfo_t *info = pinfo; ucontext_t *uc = puc; uintptr_t pc = uc->uc_mcontext.pc; - uint32_t insn = *(uint32_t *)pc; bool is_write; + struct _aarch64_ctx *hdr; + struct esr_context const *esrctx = NULL; - /* XXX: need kernel patch to get write flag faster. */ - is_write = ( (insn & 0xbfff0000) == 0x0c000000 /* C3.3.1 */ - || (insn & 0xbfe00000) == 0x0c800000 /* C3.3.2 */ - || (insn & 0xbfdf0000) == 0x0d000000 /* C3.3.3 */ - || (insn & 0xbfc00000) == 0x0d800000 /* C3.3.4 */ - || (insn & 0x3f400000) == 0x08000000 /* C3.3.6 */ - || (insn & 0x3bc00000) == 0x39000000 /* C3.3.13 */ - || (insn & 0x3fc00000) == 0x3d800000 /* ... 128bit */ - /* Ingore bits 10, 11 & 21, controlling indexing. */ - || (insn & 0x3bc00000) == 0x38000000 /* C3.3.8-12 */ - || (insn & 0x3fe00000) == 0x3c800000 /* ... 128bit */ - /* Ignore bits 23 & 24, controlling indexing. */ - || (insn & 0x3a400000) == 0x28000000); /* C3.3.7,14-16 */ + /* Find the esr_context, which has the WnR bit in it */ + for (hdr = first_ctx(uc); hdr->magic; hdr = next_ctx(hdr)) { + if (hdr->magic == ESR_MAGIC) { + esrctx = (struct esr_context const *)hdr; + break; + } + } + if (esrctx) { + /* For data aborts ESR.EC is 0b10010x: then bit 6 is the WnR bit */ + uint64_t esr = esrctx->esr; + is_write = extract32(esr, 27, 5) == 0x12 && extract32(esr, 6, 1) == 1; + } else { + /* + * Fall back to parsing instructions; will only be needed + * for really ancient (pre-3.16) kernels. + */ + uint32_t insn = *(uint32_t *)pc; + + is_write = ((insn & 0xbfff0000) == 0x0c000000 /* C3.3.1 */ + || (insn & 0xbfe00000) == 0x0c800000 /* C3.3.2 */ + || (insn & 0xbfdf0000) == 0x0d000000 /* C3.3.3 */ + || (insn & 0xbfc00000) == 0x0d800000 /* C3.3.4 */ + || (insn & 0x3f400000) == 0x08000000 /* C3.3.6 */ + || (insn & 0x3bc00000) == 0x39000000 /* C3.3.13 */ + || (insn & 0x3fc00000) == 0x3d800000 /* ... 128bit */ + /* Ignore bits 10, 11 & 21, controlling indexing. */ + || (insn & 0x3bc00000) == 0x38000000 /* C3.3.8-12 */ + || (insn & 0x3fe00000) == 0x3c800000 /* ... 128bit */ + /* Ignore bits 23 & 24, controlling indexing. */ + || (insn & 0x3a400000) == 0x28000000); /* C3.3.7,14-16 */ + } return handle_cpu_signal(pc, info, is_write, &uc->uc_sigmask); } |