ab9ccfa850
The new noexec test fails on s390x with "unexpected SEGV". This test
overwrites code using libc's memcpy(), which uses VSTL instruction.
host_signal_write() does not recognize it, which causes SEGV to be
incorrectly forwarded to the test.
Add all vector instructions that write to memory to
host_signal_write().
Fixes: ab12c95d3f ("target/s390x: Make translator stop before the end of a page")
Reported-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Message-Id: <20220920113907.334144-1-iii@linux.ibm.com>
Tested-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>
139 lines
3.9 KiB
C
139 lines
3.9 KiB
C
/*
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* host-signal.h: signal info dependent on the host architecture
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*
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* Copyright (c) 2003-2005 Fabrice Bellard
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* Copyright (c) 2021 Linaro Limited
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*
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* This work is licensed under the terms of the GNU LGPL, version 2.1 or later.
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* See the COPYING file in the top-level directory.
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*/
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#ifndef S390_HOST_SIGNAL_H
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#define S390_HOST_SIGNAL_H
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/* The third argument to a SA_SIGINFO handler is ucontext_t. */
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typedef ucontext_t host_sigcontext;
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static inline uintptr_t host_signal_pc(host_sigcontext *uc)
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{
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return uc->uc_mcontext.psw.addr;
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}
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static inline void host_signal_set_pc(host_sigcontext *uc, uintptr_t pc)
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{
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uc->uc_mcontext.psw.addr = pc;
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}
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static inline void *host_signal_mask(host_sigcontext *uc)
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{
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return &uc->uc_sigmask;
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}
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static inline bool host_signal_write(siginfo_t *info, host_sigcontext *uc)
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{
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uint16_t *pinsn = (uint16_t *)host_signal_pc(uc);
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/*
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* ??? On linux, the non-rt signal handler has 4 (!) arguments instead
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* of the normal 2 arguments. The 4th argument contains the "Translation-
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* Exception Identification for DAT Exceptions" from the hardware (aka
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* "int_parm_long"), which does in fact contain the is_write value.
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* The rt signal handler, as far as I can tell, does not give this value
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* at all. Not that we could get to it from here even if it were.
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* So fall back to parsing instructions. Treat read-modify-write ones as
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* writes, which is not fully correct, but for tracking self-modifying code
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* this is better than treating them as reads. Checking si_addr page flags
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* might be a viable improvement, albeit a racy one.
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*/
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/* ??? This is not even close to complete. */
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switch (pinsn[0] >> 8) {
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case 0x50: /* ST */
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case 0x42: /* STC */
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case 0x40: /* STH */
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case 0x44: /* EX */
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case 0xba: /* CS */
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case 0xbb: /* CDS */
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return true;
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case 0xc4: /* RIL format insns */
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switch (pinsn[0] & 0xf) {
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case 0xf: /* STRL */
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case 0xb: /* STGRL */
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case 0x7: /* STHRL */
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return true;
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}
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break;
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case 0xc6: /* RIL-b format insns */
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switch (pinsn[0] & 0xf) {
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case 0x0: /* EXRL */
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return true;
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}
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break;
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case 0xc8: /* SSF format insns */
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switch (pinsn[0] & 0xf) {
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case 0x2: /* CSST */
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return true;
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}
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break;
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case 0xe3: /* RXY format insns */
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switch (pinsn[2] & 0xff) {
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case 0x50: /* STY */
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case 0x24: /* STG */
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case 0x72: /* STCY */
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case 0x70: /* STHY */
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case 0x8e: /* STPQ */
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case 0x3f: /* STRVH */
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case 0x3e: /* STRV */
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case 0x2f: /* STRVG */
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return true;
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}
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break;
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case 0xe6:
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switch (pinsn[2] & 0xff) {
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case 0x09: /* VSTEBRH */
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case 0x0a: /* VSTEBRG */
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case 0x0b: /* VSTEBRF */
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case 0x0e: /* VSTBR */
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case 0x0f: /* VSTER */
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case 0x3f: /* VSTRLR */
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return true;
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}
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break;
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case 0xe7:
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switch (pinsn[2] & 0xff) {
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case 0x08: /* VSTEB */
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case 0x09: /* VSTEH */
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case 0x0a: /* VSTEG */
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case 0x0b: /* VSTEF */
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case 0x0e: /* VST */
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case 0x1a: /* VSCEG */
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case 0x1b: /* VSCEF */
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case 0x3e: /* VSTM */
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case 0x3f: /* VSTL */
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return true;
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}
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break;
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case 0xeb: /* RSY format insns */
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switch (pinsn[2] & 0xff) {
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case 0x14: /* CSY */
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case 0x30: /* CSG */
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case 0x31: /* CDSY */
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case 0x3e: /* CDSG */
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case 0xe4: /* LANG */
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case 0xe6: /* LAOG */
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case 0xe7: /* LAXG */
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case 0xe8: /* LAAG */
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case 0xea: /* LAALG */
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case 0xf4: /* LAN */
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case 0xf6: /* LAO */
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case 0xf7: /* LAX */
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case 0xfa: /* LAAL */
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case 0xf8: /* LAA */
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return true;
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}
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break;
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}
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return false;
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}
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#endif
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