From c6cda6a44a8adaeb30bd6dc185f021809625433d Mon Sep 17 00:00:00 2001 From: Warner Losh Date: Fri, 12 Nov 2021 21:55:59 -0700 Subject: [PATCH 1/2] linux-user: Add host_signal_set_pc to set pc in mcontext MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Add a new function host_signal_set_pc to set the next pc in an mcontext. The caller should ensure this is a valid PC for execution. Acked-by: Laurent Vivier Signed-off-by: Warner Losh Reviewed-by: Philippe Mathieu-Daudé Reviewed-by: Richard Henderson Message-Id: <20211113045603.60391-2-imp@bsdimp.com> Signed-off-by: Richard Henderson --- linux-user/host/aarch64/host-signal.h | 5 +++++ linux-user/host/alpha/host-signal.h | 5 +++++ linux-user/host/arm/host-signal.h | 5 +++++ linux-user/host/i386/host-signal.h | 5 +++++ linux-user/host/mips/host-signal.h | 5 +++++ linux-user/host/ppc/host-signal.h | 5 +++++ linux-user/host/riscv/host-signal.h | 5 +++++ linux-user/host/s390/host-signal.h | 5 +++++ linux-user/host/sparc/host-signal.h | 9 +++++++++ linux-user/host/x86_64/host-signal.h | 5 +++++ 10 files changed, 54 insertions(+) diff --git a/linux-user/host/aarch64/host-signal.h b/linux-user/host/aarch64/host-signal.h index 0c0b08383a..9770b36dc1 100644 --- a/linux-user/host/aarch64/host-signal.h +++ b/linux-user/host/aarch64/host-signal.h @@ -35,6 +35,11 @@ static inline uintptr_t host_signal_pc(ucontext_t *uc) return uc->uc_mcontext.pc; } +static inline void host_signal_set_pc(ucontext_t *uc, uintptr_t pc) +{ + uc->uc_mcontext.pc = pc; +} + static inline bool host_signal_write(siginfo_t *info, ucontext_t *uc) { struct _aarch64_ctx *hdr; diff --git a/linux-user/host/alpha/host-signal.h b/linux-user/host/alpha/host-signal.h index e080be412f..f4c942948a 100644 --- a/linux-user/host/alpha/host-signal.h +++ b/linux-user/host/alpha/host-signal.h @@ -16,6 +16,11 @@ static inline uintptr_t host_signal_pc(ucontext_t *uc) return uc->uc_mcontext.sc_pc; } +static inline void host_signal_set_pc(ucontext_t *uc, uintptr_t pc) +{ + uc->uc_mcontext.sc_pc = pc; +} + static inline bool host_signal_write(siginfo_t *info, ucontext_t *uc) { uint32_t *pc = (uint32_t *)host_signal_pc(uc); diff --git a/linux-user/host/arm/host-signal.h b/linux-user/host/arm/host-signal.h index efb165c0c5..6c095773c0 100644 --- a/linux-user/host/arm/host-signal.h +++ b/linux-user/host/arm/host-signal.h @@ -16,6 +16,11 @@ static inline uintptr_t host_signal_pc(ucontext_t *uc) return uc->uc_mcontext.arm_pc; } +static inline void host_signal_set_pc(ucontext_t *uc, uintptr_t pc) +{ + uc->uc_mcontext.arm_pc = pc; +} + static inline bool host_signal_write(siginfo_t *info, ucontext_t *uc) { /* diff --git a/linux-user/host/i386/host-signal.h b/linux-user/host/i386/host-signal.h index 4c8eef99ce..abe1ece5c9 100644 --- a/linux-user/host/i386/host-signal.h +++ b/linux-user/host/i386/host-signal.h @@ -16,6 +16,11 @@ static inline uintptr_t host_signal_pc(ucontext_t *uc) return uc->uc_mcontext.gregs[REG_EIP]; } +static inline void host_signal_set_pc(ucontext_t *uc, uintptr_t pc) +{ + uc->uc_mcontext.gregs[REG_EIP] = pc; +} + static inline bool host_signal_write(siginfo_t *info, ucontext_t *uc) { return uc->uc_mcontext.gregs[REG_TRAPNO] == 0xe diff --git a/linux-user/host/mips/host-signal.h b/linux-user/host/mips/host-signal.h index ef341f7c20..c666ed8c3f 100644 --- a/linux-user/host/mips/host-signal.h +++ b/linux-user/host/mips/host-signal.h @@ -16,6 +16,11 @@ static inline uintptr_t host_signal_pc(ucontext_t *uc) return uc->uc_mcontext.pc; } +static inline void host_signal_set_pc(ucontext_t *uc, uintptr_t pc) +{ + uc->uc_mcontext.pc = pc; +} + #if defined(__misp16) || defined(__mips_micromips) #error "Unsupported encoding" #endif diff --git a/linux-user/host/ppc/host-signal.h b/linux-user/host/ppc/host-signal.h index a491c413dc..1d8e658ff7 100644 --- a/linux-user/host/ppc/host-signal.h +++ b/linux-user/host/ppc/host-signal.h @@ -16,6 +16,11 @@ static inline uintptr_t host_signal_pc(ucontext_t *uc) return uc->uc_mcontext.regs->nip; } +static inline void host_signal_set_pc(ucontext_t *uc, uintptr_t pc) +{ + uc->uc_mcontext.regs->nip = pc; +} + static inline bool host_signal_write(siginfo_t *info, ucontext_t *uc) { return uc->uc_mcontext.regs->trap != 0x400 diff --git a/linux-user/host/riscv/host-signal.h b/linux-user/host/riscv/host-signal.h index 3b168cb58b..a4f170efb0 100644 --- a/linux-user/host/riscv/host-signal.h +++ b/linux-user/host/riscv/host-signal.h @@ -16,6 +16,11 @@ static inline uintptr_t host_signal_pc(ucontext_t *uc) return uc->uc_mcontext.__gregs[REG_PC]; } +static inline void host_signal_set_pc(ucontext_t *uc, uintptr_t pc) +{ + uc->uc_mcontext.__gregs[REG_PC] = pc; +} + static inline bool host_signal_write(siginfo_t *info, ucontext_t *uc) { /* diff --git a/linux-user/host/s390/host-signal.h b/linux-user/host/s390/host-signal.h index 26990e4893..a524f2ab00 100644 --- a/linux-user/host/s390/host-signal.h +++ b/linux-user/host/s390/host-signal.h @@ -16,6 +16,11 @@ static inline uintptr_t host_signal_pc(ucontext_t *uc) return uc->uc_mcontext.psw.addr; } +static inline void host_signal_set_pc(ucontext_t *uc, uintptr_t pc) +{ + uc->uc_mcontext.psw.addr = pc; +} + static inline bool host_signal_write(siginfo_t *info, ucontext_t *uc) { uint16_t *pinsn = (uint16_t *)host_signal_pc(uc); diff --git a/linux-user/host/sparc/host-signal.h b/linux-user/host/sparc/host-signal.h index 5e71d33f8e..7342936071 100644 --- a/linux-user/host/sparc/host-signal.h +++ b/linux-user/host/sparc/host-signal.h @@ -20,6 +20,15 @@ static inline uintptr_t host_signal_pc(ucontext_t *uc) #endif } +static inline void host_signal_set_pc(ucontext_t *uc, uintptr_t pc) +{ +#ifdef __arch64__ + uc->uc_mcontext.mc_gregs[MC_PC] = pc; +#else + uc->uc_mcontext.gregs[REG_PC] = pc; +#endif +} + static inline bool host_signal_write(siginfo_t *info, ucontext_t *uc) { uint32_t insn = *(uint32_t *)host_signal_pc(uc); diff --git a/linux-user/host/x86_64/host-signal.h b/linux-user/host/x86_64/host-signal.h index 883d2fcf65..c71d597eb2 100644 --- a/linux-user/host/x86_64/host-signal.h +++ b/linux-user/host/x86_64/host-signal.h @@ -15,6 +15,11 @@ static inline uintptr_t host_signal_pc(ucontext_t *uc) return uc->uc_mcontext.gregs[REG_RIP]; } +static inline void host_signal_set_pc(ucontext_t *uc, uintptr_t pc) +{ + uc->uc_mcontext.gregs[REG_RIP] = pc; +} + static inline bool host_signal_write(siginfo_t *info, ucontext_t *uc) { return uc->uc_mcontext.gregs[REG_TRAPNO] == 0xe From 07637888687bfecf3c0cc8351c5c24f29a611691 Mon Sep 17 00:00:00 2001 From: Warner Losh Date: Fri, 12 Nov 2021 21:56:00 -0700 Subject: [PATCH 2/2] linux-user/signal.c: Create a common rewind_if_in_safe_syscall MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit All instances of rewind_if_in_safe_syscall are the same, differing only in how the instruction point is fetched from the ucontext and the size of the registers. Use host_signal_pc and new host_signal_set_pc interfaces to fetch the pointer to the PC and adjust if needed. Delete all the old copies of rewind_if_in_safe_syscall. Acked-by: Laurent Vivier Signed-off-by: Warner Losh Reviewed-by: Richard Henderson Reviewed-by: Philippe Mathieu-Daudé Message-Id: <20211113045603.60391-3-imp@bsdimp.com> [rth: include safe-syscall.h, simplify ifdefs] Signed-off-by: Richard Henderson --- linux-user/host/aarch64/hostdep.h | 20 -------------------- linux-user/host/arm/hostdep.h | 20 -------------------- linux-user/host/i386/hostdep.h | 20 -------------------- linux-user/host/ppc64/hostdep.h | 20 -------------------- linux-user/host/riscv/hostdep.h | 20 -------------------- linux-user/host/s390x/hostdep.h | 20 -------------------- linux-user/host/x86_64/hostdep.h | 20 -------------------- linux-user/safe-syscall.h | 3 +++ linux-user/signal.c | 15 ++++++++++++--- 9 files changed, 15 insertions(+), 143 deletions(-) diff --git a/linux-user/host/aarch64/hostdep.h b/linux-user/host/aarch64/hostdep.h index a8d41a21ad..39299d798a 100644 --- a/linux-user/host/aarch64/hostdep.h +++ b/linux-user/host/aarch64/hostdep.h @@ -15,24 +15,4 @@ /* We have a safe-syscall.inc.S */ #define HAVE_SAFE_SYSCALL -#ifndef __ASSEMBLER__ - -/* These are defined by the safe-syscall.inc.S file */ -extern char safe_syscall_start[]; -extern char safe_syscall_end[]; - -/* Adjust the signal context to rewind out of safe-syscall if we're in it */ -static inline void rewind_if_in_safe_syscall(void *puc) -{ - ucontext_t *uc = puc; - __u64 *pcreg = &uc->uc_mcontext.pc; - - if (*pcreg > (uintptr_t)safe_syscall_start - && *pcreg < (uintptr_t)safe_syscall_end) { - *pcreg = (uintptr_t)safe_syscall_start; - } -} - -#endif /* __ASSEMBLER__ */ - #endif diff --git a/linux-user/host/arm/hostdep.h b/linux-user/host/arm/hostdep.h index 9276fe6ceb..86b137875a 100644 --- a/linux-user/host/arm/hostdep.h +++ b/linux-user/host/arm/hostdep.h @@ -15,24 +15,4 @@ /* We have a safe-syscall.inc.S */ #define HAVE_SAFE_SYSCALL -#ifndef __ASSEMBLER__ - -/* These are defined by the safe-syscall.inc.S file */ -extern char safe_syscall_start[]; -extern char safe_syscall_end[]; - -/* Adjust the signal context to rewind out of safe-syscall if we're in it */ -static inline void rewind_if_in_safe_syscall(void *puc) -{ - ucontext_t *uc = puc; - unsigned long *pcreg = &uc->uc_mcontext.arm_pc; - - if (*pcreg > (uintptr_t)safe_syscall_start - && *pcreg < (uintptr_t)safe_syscall_end) { - *pcreg = (uintptr_t)safe_syscall_start; - } -} - -#endif /* __ASSEMBLER__ */ - #endif diff --git a/linux-user/host/i386/hostdep.h b/linux-user/host/i386/hostdep.h index 073be74d87..ce7136501f 100644 --- a/linux-user/host/i386/hostdep.h +++ b/linux-user/host/i386/hostdep.h @@ -15,24 +15,4 @@ /* We have a safe-syscall.inc.S */ #define HAVE_SAFE_SYSCALL -#ifndef __ASSEMBLER__ - -/* These are defined by the safe-syscall.inc.S file */ -extern char safe_syscall_start[]; -extern char safe_syscall_end[]; - -/* Adjust the signal context to rewind out of safe-syscall if we're in it */ -static inline void rewind_if_in_safe_syscall(void *puc) -{ - ucontext_t *uc = puc; - greg_t *pcreg = &uc->uc_mcontext.gregs[REG_EIP]; - - if (*pcreg > (uintptr_t)safe_syscall_start - && *pcreg < (uintptr_t)safe_syscall_end) { - *pcreg = (uintptr_t)safe_syscall_start; - } -} - -#endif /* __ASSEMBLER__ */ - #endif diff --git a/linux-user/host/ppc64/hostdep.h b/linux-user/host/ppc64/hostdep.h index 98979ad917..0c290dd904 100644 --- a/linux-user/host/ppc64/hostdep.h +++ b/linux-user/host/ppc64/hostdep.h @@ -15,24 +15,4 @@ /* We have a safe-syscall.inc.S */ #define HAVE_SAFE_SYSCALL -#ifndef __ASSEMBLER__ - -/* These are defined by the safe-syscall.inc.S file */ -extern char safe_syscall_start[]; -extern char safe_syscall_end[]; - -/* Adjust the signal context to rewind out of safe-syscall if we're in it */ -static inline void rewind_if_in_safe_syscall(void *puc) -{ - ucontext_t *uc = puc; - unsigned long *pcreg = &uc->uc_mcontext.gp_regs[PT_NIP]; - - if (*pcreg > (uintptr_t)safe_syscall_start - && *pcreg < (uintptr_t)safe_syscall_end) { - *pcreg = (uintptr_t)safe_syscall_start; - } -} - -#endif /* __ASSEMBLER__ */ - #endif diff --git a/linux-user/host/riscv/hostdep.h b/linux-user/host/riscv/hostdep.h index 2ba07456ae..7f67c22868 100644 --- a/linux-user/host/riscv/hostdep.h +++ b/linux-user/host/riscv/hostdep.h @@ -11,24 +11,4 @@ /* We have a safe-syscall.inc.S */ #define HAVE_SAFE_SYSCALL -#ifndef __ASSEMBLER__ - -/* These are defined by the safe-syscall.inc.S file */ -extern char safe_syscall_start[]; -extern char safe_syscall_end[]; - -/* Adjust the signal context to rewind out of safe-syscall if we're in it */ -static inline void rewind_if_in_safe_syscall(void *puc) -{ - ucontext_t *uc = puc; - unsigned long *pcreg = &uc->uc_mcontext.__gregs[REG_PC]; - - if (*pcreg > (uintptr_t)safe_syscall_start - && *pcreg < (uintptr_t)safe_syscall_end) { - *pcreg = (uintptr_t)safe_syscall_start; - } -} - -#endif /* __ASSEMBLER__ */ - #endif diff --git a/linux-user/host/s390x/hostdep.h b/linux-user/host/s390x/hostdep.h index 4f0171f36f..d801145854 100644 --- a/linux-user/host/s390x/hostdep.h +++ b/linux-user/host/s390x/hostdep.h @@ -15,24 +15,4 @@ /* We have a safe-syscall.inc.S */ #define HAVE_SAFE_SYSCALL -#ifndef __ASSEMBLER__ - -/* These are defined by the safe-syscall.inc.S file */ -extern char safe_syscall_start[]; -extern char safe_syscall_end[]; - -/* Adjust the signal context to rewind out of safe-syscall if we're in it */ -static inline void rewind_if_in_safe_syscall(void *puc) -{ - ucontext_t *uc = puc; - unsigned long *pcreg = &uc->uc_mcontext.psw.addr; - - if (*pcreg > (uintptr_t)safe_syscall_start - && *pcreg < (uintptr_t)safe_syscall_end) { - *pcreg = (uintptr_t)safe_syscall_start; - } -} - -#endif /* __ASSEMBLER__ */ - #endif diff --git a/linux-user/host/x86_64/hostdep.h b/linux-user/host/x86_64/hostdep.h index a4fefb5114..9c62bd26bd 100644 --- a/linux-user/host/x86_64/hostdep.h +++ b/linux-user/host/x86_64/hostdep.h @@ -15,24 +15,4 @@ /* We have a safe-syscall.inc.S */ #define HAVE_SAFE_SYSCALL -#ifndef __ASSEMBLER__ - -/* These are defined by the safe-syscall.inc.S file */ -extern char safe_syscall_start[]; -extern char safe_syscall_end[]; - -/* Adjust the signal context to rewind out of safe-syscall if we're in it */ -static inline void rewind_if_in_safe_syscall(void *puc) -{ - ucontext_t *uc = puc; - greg_t *pcreg = &uc->uc_mcontext.gregs[REG_RIP]; - - if (*pcreg > (uintptr_t)safe_syscall_start - && *pcreg < (uintptr_t)safe_syscall_end) { - *pcreg = (uintptr_t)safe_syscall_start; - } -} - -#endif /* __ASSEMBLER__ */ - #endif diff --git a/linux-user/safe-syscall.h b/linux-user/safe-syscall.h index 6bc0390262..aaa9ffc0e2 100644 --- a/linux-user/safe-syscall.h +++ b/linux-user/safe-syscall.h @@ -127,6 +127,9 @@ #ifdef HAVE_SAFE_SYSCALL /* The core part of this function is implemented in assembly */ extern long safe_syscall_base(int *pending, long number, ...); +/* These are defined by the safe-syscall.inc.S file */ +extern char safe_syscall_start[]; +extern char safe_syscall_end[]; #define safe_syscall(...) \ ({ \ diff --git a/linux-user/signal.c b/linux-user/signal.c index 81c45bfce9..6d5e5b698c 100644 --- a/linux-user/signal.c +++ b/linux-user/signal.c @@ -31,6 +31,7 @@ #include "trace.h" #include "signal-common.h" #include "host-signal.h" +#include "safe-syscall.h" static struct target_sigaction sigact_table[TARGET_NSIG]; @@ -793,12 +794,20 @@ int queue_signal(CPUArchState *env, int sig, int si_type, return 1; /* indicates that the signal was queued */ } -#ifndef HAVE_SAFE_SYSCALL + +/* Adjust the signal context to rewind out of safe-syscall if we're in it */ static inline void rewind_if_in_safe_syscall(void *puc) { - /* Default version: never rewind */ -} +#ifdef HAVE_SAFE_SYSCALL + ucontext_t *uc = (ucontext_t *)puc; + uintptr_t pcreg = host_signal_pc(uc); + + if (pcreg > (uintptr_t)safe_syscall_start + && pcreg < (uintptr_t)safe_syscall_end) { + host_signal_set_pc(uc, (uintptr_t)safe_syscall_start); + } #endif +} static void host_signal_handler(int host_sig, siginfo_t *info, void *puc) {