| Message ID | 20211117160412.71563-3-richard.henderson@linaro.org |
|---|---|
| State | Superseded |
| Headers | show |
| Series | linux-user: simplify safe signal handling | expand |
On Wed, Nov 17, 2021 at 9:04 AM Richard Henderson < richard.henderson@linaro.org> wrote: > From: Warner Losh <imp@bsdimp.com> > > 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. > > Signed-off-by: Warner Losh <imp@bsdimp.com> > Reviewed-by: Richard Henderson <richard.henderson@linaro.org> > Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org> > Message-Id: <20211113045603.60391-3-imp@bsdimp.com> > [rth: include safe-syscall.h, simplify ifdefs] > Signed-off-by: Richard Henderson <richard.henderson@linaro.org> > --- > 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(-) > Reviewed by: Warner Losh <imp@bsdimp.com> (this one I'm sure it's ok since things changed from my original and the changes are good). > 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) > { > -- > 2.25.1 > >
Richard Henderson <richard.henderson@linaro.org> writes: > From: Warner Losh <imp@bsdimp.com> > > 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. > > Signed-off-by: Warner Losh <imp@bsdimp.com> > Reviewed-by: Richard Henderson <richard.henderson@linaro.org> > Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org> > Message-Id: <20211113045603.60391-3-imp@bsdimp.com> > [rth: include safe-syscall.h, simplify ifdefs] > Signed-off-by: Richard Henderson <richard.henderson@linaro.org> Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
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) {