| Message ID | 20230524054647.1093758-1-richard.henderson@linaro.org |
|---|---|
| State | New |
| Headers | show |
| Series | linux-user/i386: Properly align signal frame | expand |
On 5/23/23 22:46, Richard Henderson wrote: > The beginning of the structure, with pretaddr, should be just below > 16-byte alignment. Disconnect fpstate from sigframe, just like the > kernel does. > > Signed-off-by: Richard Henderson <richard.henderson@linaro.org> > --- > linux-user/i386/signal.c | 104 +++++++++++++++++-------------- > tests/tcg/x86_64/sigstack.c | 33 ++++++++++ > tests/tcg/x86_64/Makefile.target | 1 + > 3 files changed, 90 insertions(+), 48 deletions(-) > create mode 100644 tests/tcg/x86_64/sigstack.c Oops, meant to add Resolves: https://gitlab.com/qemu-project/qemu/-/issues/1648 r~ > > diff --git a/linux-user/i386/signal.c b/linux-user/i386/signal.c > index 60fa07d6f9..c49467de78 100644 > --- a/linux-user/i386/signal.c > +++ b/linux-user/i386/signal.c > @@ -191,16 +191,7 @@ struct sigframe { > struct target_fpstate fpstate_unused; > abi_ulong extramask[TARGET_NSIG_WORDS-1]; > char retcode[8]; > - > - /* > - * This field will be 16-byte aligned in memory. Applying QEMU_ALIGNED > - * to it ensures that the base of the frame has an appropriate alignment > - * too. > - */ > - struct target_fpstate fpstate QEMU_ALIGNED(8); > }; > -#define TARGET_SIGFRAME_FXSAVE_OFFSET ( \ > - offsetof(struct sigframe, fpstate) + TARGET_FPSTATE_FXSAVE_OFFSET) > > struct rt_sigframe { > abi_ulong pretcode; > @@ -210,27 +201,21 @@ struct rt_sigframe { > struct target_siginfo info; > struct target_ucontext uc; > char retcode[8]; > - struct target_fpstate fpstate QEMU_ALIGNED(8); > }; > -#define TARGET_RT_SIGFRAME_FXSAVE_OFFSET ( \ > - offsetof(struct rt_sigframe, fpstate) + TARGET_FPSTATE_FXSAVE_OFFSET) > #else > - > struct rt_sigframe { > abi_ulong pretcode; > struct target_ucontext uc; > struct target_siginfo info; > - struct target_fpstate fpstate QEMU_ALIGNED(16); > }; > -#define TARGET_RT_SIGFRAME_FXSAVE_OFFSET ( \ > - offsetof(struct rt_sigframe, fpstate) + TARGET_FPSTATE_FXSAVE_OFFSET) > #endif > > /* > * Set up a signal frame. > */ > > -static void xsave_sigcontext(CPUX86State *env, struct target_fpstate_fxsave *fxsave, > +static void xsave_sigcontext(CPUX86State *env, > + struct target_fpstate_fxsave *fxsave, > abi_ulong fxsave_addr) > { > if (!(env->features[FEAT_1_ECX] & CPUID_EXT_XSAVE)) { > @@ -266,8 +251,9 @@ static void xsave_sigcontext(CPUX86State *env, struct target_fpstate_fxsave *fxs > } > > static void setup_sigcontext(struct target_sigcontext *sc, > - struct target_fpstate *fpstate, CPUX86State *env, abi_ulong mask, > - abi_ulong fpstate_addr) > + struct target_fpstate *fpstate, > + CPUX86State *env, abi_ulong mask, > + abi_ulong fpstate_addr) > { > CPUState *cs = env_cpu(env); > #ifndef TARGET_X86_64 > @@ -347,10 +333,11 @@ static void setup_sigcontext(struct target_sigcontext *sc, > * Determine which stack to use.. > */ > > -static inline abi_ulong > -get_sigframe(struct target_sigaction *ka, CPUX86State *env, size_t fxsave_offset) > +static abi_ulong get_sigframe(struct target_sigaction *ka, CPUX86State *env, > + size_t *frame_size, abi_ulong *fpsave_addr) > { > - unsigned long esp; > + abi_ulong esp, orig; > + size_t fpsave_size; > > /* Default to using normal stack */ > esp = get_sp_from_cpustate(env); > @@ -371,16 +358,23 @@ get_sigframe(struct target_sigaction *ka, CPUX86State *env, size_t fxsave_offset > } > #endif > } > + orig = esp; > > - if (!(env->features[FEAT_1_EDX] & CPUID_FXSR)) { > - return (esp - (fxsave_offset + TARGET_FXSAVE_SIZE)) & -8ul; > - } else if (!(env->features[FEAT_1_ECX] & CPUID_EXT_XSAVE)) { > - return ((esp - TARGET_FXSAVE_SIZE) & -16ul) - fxsave_offset; > + if (!(env->features[FEAT_1_ECX] & CPUID_EXT_XSAVE)) { > + fpsave_size = TARGET_FXSAVE_SIZE; > + esp = ROUND_DOWN(esp - fpsave_size, 16); > } else { > - size_t xstate_size = > - xsave_area_size(env->xcr0, false) + TARGET_FP_XSTATE_MAGIC2_SIZE; > - return ((esp - xstate_size) & -64ul) - fxsave_offset; > + fpsave_size = xsave_area_size(env->xcr0, false) > + + TARGET_FP_XSTATE_MAGIC2_SIZE; > + esp = ROUND_DOWN(esp - fpsave_size, 64); > } > + *fpsave_addr = esp; > + > + esp = esp - *frame_size + sizeof(abi_ulong); > + esp = ROUND_DOWN(esp, 16) - sizeof(abi_ulong); > + > + *frame_size = orig - esp; > + return esp; > } > > #ifndef TARGET_X86_64 > @@ -405,26 +399,34 @@ void setup_frame(int sig, struct target_sigaction *ka, > target_sigset_t *set, CPUX86State *env) > { > abi_ulong frame_addr; > + abi_ulong fpstate_addr; > + size_t frame_size; > struct sigframe *frame; > + struct target_fpstate *fpstate; > int i; > > - frame_addr = get_sigframe(ka, env, TARGET_SIGFRAME_FXSAVE_OFFSET); > + frame_size = sizeof(struct sigframe); > + frame_addr = get_sigframe(ka, env, &frame_size, &fpstate_addr); > trace_user_setup_frame(env, frame_addr); > > - if (!lock_user_struct(VERIFY_WRITE, frame, frame_addr, 0)) > + frame = lock_user(VERIFY_WRITE, frame_addr, frame_size, false); > + if (!frame) { > goto give_sigsegv; > + } > + fpstate = (void *)frame + (fpstate_addr - frame_addr); > > __put_user(sig, &frame->sig); > > - setup_sigcontext(&frame->sc, &frame->fpstate, env, set->sig[0], > - frame_addr + offsetof(struct sigframe, fpstate)); > + setup_sigcontext(&frame->sc, fpstate, env, set->sig[0], fpstate_addr); > > - for(i = 1; i < TARGET_NSIG_WORDS; i++) { > + for (i = 1; i < TARGET_NSIG_WORDS; i++) { > __put_user(set->sig[i], &frame->extramask[i - 1]); > } > > - /* Set up to return from userspace. If provided, use a stub > - already in userspace. */ > + /* > + * Set up to return from userspace. > + * If provided, use a stub already in userspace. > + */ > if (ka->sa_flags & TARGET_SA_RESTORER) { > __put_user(ka->sa_restorer, &frame->pretcode); > } else { > @@ -443,11 +445,10 @@ void setup_frame(int sig, struct target_sigaction *ka, > cpu_x86_load_seg(env, R_CS, __USER_CS); > env->eflags &= ~TF_MASK; > > - unlock_user_struct(frame, frame_addr, 1); > - > + unlock_user(frame, frame_addr, frame_size); > return; > > -give_sigsegv: > + give_sigsegv: > force_sigsegv(sig); > } > #endif > @@ -458,17 +459,24 @@ void setup_rt_frame(int sig, struct target_sigaction *ka, > target_sigset_t *set, CPUX86State *env) > { > abi_ulong frame_addr; > + abi_ulong fpstate_addr; > + size_t frame_size; > #ifndef TARGET_X86_64 > abi_ulong addr; > #endif > struct rt_sigframe *frame; > + struct target_fpstate *fpstate; > int i; > > - frame_addr = get_sigframe(ka, env, TARGET_RT_SIGFRAME_FXSAVE_OFFSET); > + frame_size = sizeof(struct rt_sigframe); > + frame_addr = get_sigframe(ka, env, &frame_size, &fpstate_addr); > trace_user_setup_rt_frame(env, frame_addr); > > - if (!lock_user_struct(VERIFY_WRITE, frame, frame_addr, 0)) > + frame = lock_user(VERIFY_WRITE, frame_addr, frame_size, false); > + if (!frame) { > goto give_sigsegv; > + } > + fpstate = (void *)frame + (fpstate_addr - frame_addr); > > /* These fields are only in rt_sigframe on 32 bit */ > #ifndef TARGET_X86_64 > @@ -490,10 +498,10 @@ void setup_rt_frame(int sig, struct target_sigaction *ka, > } > __put_user(0, &frame->uc.tuc_link); > target_save_altstack(&frame->uc.tuc_stack, env); > - setup_sigcontext(&frame->uc.tuc_mcontext, &frame->fpstate, env, > - set->sig[0], frame_addr + offsetof(struct rt_sigframe, fpstate)); > + setup_sigcontext(&frame->uc.tuc_mcontext, fpstate, env, > + set->sig[0], fpstate_addr); > > - for(i = 0; i < TARGET_NSIG_WORDS; i++) { > + for (i = 0; i < TARGET_NSIG_WORDS; i++) { > __put_user(set->sig[i], &frame->uc.tuc_sigmask.sig[i]); > } > > @@ -533,15 +541,15 @@ void setup_rt_frame(int sig, struct target_sigaction *ka, > cpu_x86_load_seg(env, R_SS, __USER_DS); > env->eflags &= ~TF_MASK; > > - unlock_user_struct(frame, frame_addr, 1); > - > + unlock_user(frame, frame_addr, frame_size); > return; > > -give_sigsegv: > + give_sigsegv: > force_sigsegv(sig); > } > > -static int xrstor_sigcontext(CPUX86State *env, struct target_fpstate_fxsave *fxsave, > +static int xrstor_sigcontext(CPUX86State *env, > + struct target_fpstate_fxsave *fxsave, > abi_ulong fxsave_addr) > { > if (env->features[FEAT_1_ECX] & CPUID_EXT_XSAVE) { > diff --git a/tests/tcg/x86_64/sigstack.c b/tests/tcg/x86_64/sigstack.c > new file mode 100644 > index 0000000000..06cb847569 > --- /dev/null > +++ b/tests/tcg/x86_64/sigstack.c > @@ -0,0 +1,33 @@ > +#include <stdlib.h> > +#include <assert.h> > +#include <signal.h> > +#include <stdint.h> > + > +void __attribute__((noinline)) bar(void) > +{ > + exit(EXIT_SUCCESS); > +} > + > +void __attribute__((noinline, ms_abi)) foo(void) > +{ > + /* > + * With ms_abi, there are call-saved xmm registers, which are forced > + * to the stack around the call to sysv_abi bar(). If the signal > + * stack frame is not properly aligned, movaps will raise #GP. > + */ > + bar(); > +} > + > +void sighandler(int num) > +{ > + void* sp = __builtin_dwarf_cfa(); > + assert((uintptr_t)sp % 16 == 0); > + foo(); > +} > + > +int main(void) > +{ > + signal(SIGUSR1, sighandler); > + raise(SIGUSR1); > + abort(); > +} > diff --git a/tests/tcg/x86_64/Makefile.target b/tests/tcg/x86_64/Makefile.target > index e64aab1b81..d961599f64 100644 > --- a/tests/tcg/x86_64/Makefile.target > +++ b/tests/tcg/x86_64/Makefile.target > @@ -13,6 +13,7 @@ X86_64_TESTS += vsyscall > X86_64_TESTS += noexec > X86_64_TESTS += cmpxchg > X86_64_TESTS += adox > +X86_64_TESTS += sigstack > TESTS=$(MULTIARCH_TESTS) $(X86_64_TESTS) test-x86_64 > else > TESTS=$(MULTIARCH_TESTS)
"The beginning of the structure, with pretaddr, should be just below 16-byte alignment." It is incorrect! The beginning of the structure, with pretaddr not aligned as 16-byte! On x86-64, It aligned as (16n - sizeof(void*)) because of instruction "call" ! > -----原始邮件----- > 发件人: "Richard Henderson" <richard.henderson@linaro.org> > 发送时间: 2023-05-24 13:50:43 (星期三) > 收件人: qemu-devel@nongnu.org > 抄送: fanwj@mail.ustc.edu.cn, laurent@vivier.eu > 主题: Re: [PATCH] linux-user/i386: Properly align signal frame > > On 5/23/23 22:46, Richard Henderson wrote: > > The beginning of the structure, with pretaddr, should be just below > > 16-byte alignment. Disconnect fpstate from sigframe, just like the > > kernel does. > > > > Signed-off-by: Richard Henderson <richard.henderson@linaro.org> > > --- > > linux-user/i386/signal.c | 104 +++++++++++++++++-------------- > > tests/tcg/x86_64/sigstack.c | 33 ++++++++++ > > tests/tcg/x86_64/Makefile.target | 1 + > > 3 files changed, 90 insertions(+), 48 deletions(-) > > create mode 100644 tests/tcg/x86_64/sigstack.c > > Oops, meant to add > > Resolves: https://gitlab.com/qemu-project/qemu/-/issues/1648 > > r~ > > > > > diff --git a/linux-user/i386/signal.c b/linux-user/i386/signal.c > > index 60fa07d6f9..c49467de78 100644 > > --- a/linux-user/i386/signal.c > > +++ b/linux-user/i386/signal.c > > @@ -191,16 +191,7 @@ struct sigframe { > > struct target_fpstate fpstate_unused; > > abi_ulong extramask[TARGET_NSIG_WORDS-1]; > > char retcode[8]; > > - > > - /* > > - * This field will be 16-byte aligned in memory. Applying QEMU_ALIGNED > > - * to it ensures that the base of the frame has an appropriate alignment > > - * too. > > - */ > > - struct target_fpstate fpstate QEMU_ALIGNED(8); > > }; > > -#define TARGET_SIGFRAME_FXSAVE_OFFSET ( \ > > - offsetof(struct sigframe, fpstate) + TARGET_FPSTATE_FXSAVE_OFFSET) > > > > struct rt_sigframe { > > abi_ulong pretcode; > > @@ -210,27 +201,21 @@ struct rt_sigframe { > > struct target_siginfo info; > > struct target_ucontext uc; > > char retcode[8]; > > - struct target_fpstate fpstate QEMU_ALIGNED(8); > > }; > > -#define TARGET_RT_SIGFRAME_FXSAVE_OFFSET ( \ > > - offsetof(struct rt_sigframe, fpstate) + TARGET_FPSTATE_FXSAVE_OFFSET) > > #else > > - > > struct rt_sigframe { > > abi_ulong pretcode; > > struct target_ucontext uc; > > struct target_siginfo info; > > - struct target_fpstate fpstate QEMU_ALIGNED(16); > > }; > > -#define TARGET_RT_SIGFRAME_FXSAVE_OFFSET ( \ > > - offsetof(struct rt_sigframe, fpstate) + TARGET_FPSTATE_FXSAVE_OFFSET) > > #endif > > > > /* > > * Set up a signal frame. > > */ > > > > -static void xsave_sigcontext(CPUX86State *env, struct target_fpstate_fxsave *fxsave, > > +static void xsave_sigcontext(CPUX86State *env, > > + struct target_fpstate_fxsave *fxsave, > > abi_ulong fxsave_addr) > > { > > if (!(env->features[FEAT_1_ECX] & CPUID_EXT_XSAVE)) { > > @@ -266,8 +251,9 @@ static void xsave_sigcontext(CPUX86State *env, struct target_fpstate_fxsave *fxs > > } > > > > static void setup_sigcontext(struct target_sigcontext *sc, > > - struct target_fpstate *fpstate, CPUX86State *env, abi_ulong mask, > > - abi_ulong fpstate_addr) > > + struct target_fpstate *fpstate, > > + CPUX86State *env, abi_ulong mask, > > + abi_ulong fpstate_addr) > > { > > CPUState *cs = env_cpu(env); > > #ifndef TARGET_X86_64 > > @@ -347,10 +333,11 @@ static void setup_sigcontext(struct target_sigcontext *sc, > > * Determine which stack to use.. > > */ > > > > -static inline abi_ulong > > -get_sigframe(struct target_sigaction *ka, CPUX86State *env, size_t fxsave_offset) > > +static abi_ulong get_sigframe(struct target_sigaction *ka, CPUX86State *env, > > + size_t *frame_size, abi_ulong *fpsave_addr) > > { > > - unsigned long esp; > > + abi_ulong esp, orig; > > + size_t fpsave_size; > > > > /* Default to using normal stack */ > > esp = get_sp_from_cpustate(env); > > @@ -371,16 +358,23 @@ get_sigframe(struct target_sigaction *ka, CPUX86State *env, size_t fxsave_offset > > } > > #endif > > } > > + orig = esp; > > > > - if (!(env->features[FEAT_1_EDX] & CPUID_FXSR)) { > > - return (esp - (fxsave_offset + TARGET_FXSAVE_SIZE)) & -8ul; > > - } else if (!(env->features[FEAT_1_ECX] & CPUID_EXT_XSAVE)) { > > - return ((esp - TARGET_FXSAVE_SIZE) & -16ul) - fxsave_offset; > > + if (!(env->features[FEAT_1_ECX] & CPUID_EXT_XSAVE)) { > > + fpsave_size = TARGET_FXSAVE_SIZE; > > + esp = ROUND_DOWN(esp - fpsave_size, 16); > > } else { > > - size_t xstate_size = > > - xsave_area_size(env->xcr0, false) + TARGET_FP_XSTATE_MAGIC2_SIZE; > > - return ((esp - xstate_size) & -64ul) - fxsave_offset; > > + fpsave_size = xsave_area_size(env->xcr0, false) > > + + TARGET_FP_XSTATE_MAGIC2_SIZE; > > + esp = ROUND_DOWN(esp - fpsave_size, 64); > > } > > + *fpsave_addr = esp; > > + > > + esp = esp - *frame_size + sizeof(abi_ulong); > > + esp = ROUND_DOWN(esp, 16) - sizeof(abi_ulong); > > + > > + *frame_size = orig - esp; > > + return esp; > > } > > > > #ifndef TARGET_X86_64 > > @@ -405,26 +399,34 @@ void setup_frame(int sig, struct target_sigaction *ka, > > target_sigset_t *set, CPUX86State *env) > > { > > abi_ulong frame_addr; > > + abi_ulong fpstate_addr; > > + size_t frame_size; > > struct sigframe *frame; > > + struct target_fpstate *fpstate; > > int i; > > > > - frame_addr = get_sigframe(ka, env, TARGET_SIGFRAME_FXSAVE_OFFSET); > > + frame_size = sizeof(struct sigframe); > > + frame_addr = get_sigframe(ka, env, &frame_size, &fpstate_addr); > > trace_user_setup_frame(env, frame_addr); > > > > - if (!lock_user_struct(VERIFY_WRITE, frame, frame_addr, 0)) > > + frame = lock_user(VERIFY_WRITE, frame_addr, frame_size, false); > > + if (!frame) { > > goto give_sigsegv; > > + } > > + fpstate = (void *)frame + (fpstate_addr - frame_addr); > > > > __put_user(sig, &frame->sig); > > > > - setup_sigcontext(&frame->sc, &frame->fpstate, env, set->sig[0], > > - frame_addr + offsetof(struct sigframe, fpstate)); > > + setup_sigcontext(&frame->sc, fpstate, env, set->sig[0], fpstate_addr); > > > > - for(i = 1; i < TARGET_NSIG_WORDS; i++) { > > + for (i = 1; i < TARGET_NSIG_WORDS; i++) { > > __put_user(set->sig[i], &frame->extramask[i - 1]); > > } > > > > - /* Set up to return from userspace. If provided, use a stub > > - already in userspace. */ > > + /* > > + * Set up to return from userspace. > > + * If provided, use a stub already in userspace. > > + */ > > if (ka->sa_flags & TARGET_SA_RESTORER) { > > __put_user(ka->sa_restorer, &frame->pretcode); > > } else { > > @@ -443,11 +445,10 @@ void setup_frame(int sig, struct target_sigaction *ka, > > cpu_x86_load_seg(env, R_CS, __USER_CS); > > env->eflags &= ~TF_MASK; > > > > - unlock_user_struct(frame, frame_addr, 1); > > - > > + unlock_user(frame, frame_addr, frame_size); > > return; > > > > -give_sigsegv: > > + give_sigsegv: > > force_sigsegv(sig); > > } > > #endif > > @@ -458,17 +459,24 @@ void setup_rt_frame(int sig, struct target_sigaction *ka, > > target_sigset_t *set, CPUX86State *env) > > { > > abi_ulong frame_addr; > > + abi_ulong fpstate_addr; > > + size_t frame_size; > > #ifndef TARGET_X86_64 > > abi_ulong addr; > > #endif > > struct rt_sigframe *frame; > > + struct target_fpstate *fpstate; > > int i; > > > > - frame_addr = get_sigframe(ka, env, TARGET_RT_SIGFRAME_FXSAVE_OFFSET); > > + frame_size = sizeof(struct rt_sigframe); > > + frame_addr = get_sigframe(ka, env, &frame_size, &fpstate_addr); > > trace_user_setup_rt_frame(env, frame_addr); > > > > - if (!lock_user_struct(VERIFY_WRITE, frame, frame_addr, 0)) > > + frame = lock_user(VERIFY_WRITE, frame_addr, frame_size, false); > > + if (!frame) { > > goto give_sigsegv; > > + } > > + fpstate = (void *)frame + (fpstate_addr - frame_addr); > > > > /* These fields are only in rt_sigframe on 32 bit */ > > #ifndef TARGET_X86_64 > > @@ -490,10 +498,10 @@ void setup_rt_frame(int sig, struct target_sigaction *ka, > > } > > __put_user(0, &frame->uc.tuc_link); > > target_save_altstack(&frame->uc.tuc_stack, env); > > - setup_sigcontext(&frame->uc.tuc_mcontext, &frame->fpstate, env, > > - set->sig[0], frame_addr + offsetof(struct rt_sigframe, fpstate)); > > + setup_sigcontext(&frame->uc.tuc_mcontext, fpstate, env, > > + set->sig[0], fpstate_addr); > > > > - for(i = 0; i < TARGET_NSIG_WORDS; i++) { > > + for (i = 0; i < TARGET_NSIG_WORDS; i++) { > > __put_user(set->sig[i], &frame->uc.tuc_sigmask.sig[i]); > > } > > > > @@ -533,15 +541,15 @@ void setup_rt_frame(int sig, struct target_sigaction *ka, > > cpu_x86_load_seg(env, R_SS, __USER_DS); > > env->eflags &= ~TF_MASK; > > > > - unlock_user_struct(frame, frame_addr, 1); > > - > > + unlock_user(frame, frame_addr, frame_size); > > return; > > > > -give_sigsegv: > > + give_sigsegv: > > force_sigsegv(sig); > > } > > > > -static int xrstor_sigcontext(CPUX86State *env, struct target_fpstate_fxsave *fxsave, > > +static int xrstor_sigcontext(CPUX86State *env, > > + struct target_fpstate_fxsave *fxsave, > > abi_ulong fxsave_addr) > > { > > if (env->features[FEAT_1_ECX] & CPUID_EXT_XSAVE) { > > diff --git a/tests/tcg/x86_64/sigstack.c b/tests/tcg/x86_64/sigstack.c > > new file mode 100644 > > index 0000000000..06cb847569 > > --- /dev/null > > +++ b/tests/tcg/x86_64/sigstack.c > > @@ -0,0 +1,33 @@ > > +#include <stdlib.h> > > +#include <assert.h> > > +#include <signal.h> > > +#include <stdint.h> > > + > > +void __attribute__((noinline)) bar(void) > > +{ > > + exit(EXIT_SUCCESS); > > +} > > + > > +void __attribute__((noinline, ms_abi)) foo(void) > > +{ > > + /* > > + * With ms_abi, there are call-saved xmm registers, which are forced > > + * to the stack around the call to sysv_abi bar(). If the signal > > + * stack frame is not properly aligned, movaps will raise #GP. > > + */ > > + bar(); > > +} > > + > > +void sighandler(int num) > > +{ > > + void* sp = __builtin_dwarf_cfa(); > > + assert((uintptr_t)sp % 16 == 0); > > + foo(); > > +} > > + > > +int main(void) > > +{ > > + signal(SIGUSR1, sighandler); > > + raise(SIGUSR1); > > + abort(); > > +} > > diff --git a/tests/tcg/x86_64/Makefile.target b/tests/tcg/x86_64/Makefile.target > > index e64aab1b81..d961599f64 100644 > > --- a/tests/tcg/x86_64/Makefile.target > > +++ b/tests/tcg/x86_64/Makefile.target > > @@ -13,6 +13,7 @@ X86_64_TESTS += vsyscall > > X86_64_TESTS += noexec > > X86_64_TESTS += cmpxchg > > X86_64_TESTS += adox > > +X86_64_TESTS += sigstack > > TESTS=$(MULTIARCH_TESTS) $(X86_64_TESTS) test-x86_64 > > else > > TESTS=$(MULTIARCH_TESTS) >
On 5/25/23 19:56, fanwj@mail.ustc.edu.cn wrote: > > "The beginning of the structure, with pretaddr, should be just below 16-byte alignment." > > It is incorrect! The beginning of the structure, with pretaddr not aligned as 16-byte! > On x86-64, It aligned as (16n - sizeof(void*)) because of instruction "call" ! Exactly: 16n - sizeof(void*) is why I mean by "just below 16-byte alignment". Which is exactly what I have done... >>> + esp = esp - *frame_size + sizeof(abi_ulong); >>> + esp = ROUND_DOWN(esp, 16) - sizeof(abi_ulong); ... here. r~
Ping. On 5/24/23 07:46, Richard Henderson wrote: > The beginning of the structure, with pretaddr, should be just below > 16-byte alignment. Disconnect fpstate from sigframe, just like the > kernel does. > > Signed-off-by: Richard Henderson <richard.henderson@linaro.org> > --- > linux-user/i386/signal.c | 104 +++++++++++++++++-------------- > tests/tcg/x86_64/sigstack.c | 33 ++++++++++ > tests/tcg/x86_64/Makefile.target | 1 + > 3 files changed, 90 insertions(+), 48 deletions(-) > create mode 100644 tests/tcg/x86_64/sigstack.c > > diff --git a/linux-user/i386/signal.c b/linux-user/i386/signal.c > index 60fa07d6f9..c49467de78 100644 > --- a/linux-user/i386/signal.c > +++ b/linux-user/i386/signal.c > @@ -191,16 +191,7 @@ struct sigframe { > struct target_fpstate fpstate_unused; > abi_ulong extramask[TARGET_NSIG_WORDS-1]; > char retcode[8]; > - > - /* > - * This field will be 16-byte aligned in memory. Applying QEMU_ALIGNED > - * to it ensures that the base of the frame has an appropriate alignment > - * too. > - */ > - struct target_fpstate fpstate QEMU_ALIGNED(8); > }; > -#define TARGET_SIGFRAME_FXSAVE_OFFSET ( \ > - offsetof(struct sigframe, fpstate) + TARGET_FPSTATE_FXSAVE_OFFSET) > > struct rt_sigframe { > abi_ulong pretcode; > @@ -210,27 +201,21 @@ struct rt_sigframe { > struct target_siginfo info; > struct target_ucontext uc; > char retcode[8]; > - struct target_fpstate fpstate QEMU_ALIGNED(8); > }; > -#define TARGET_RT_SIGFRAME_FXSAVE_OFFSET ( \ > - offsetof(struct rt_sigframe, fpstate) + TARGET_FPSTATE_FXSAVE_OFFSET) > #else > - > struct rt_sigframe { > abi_ulong pretcode; > struct target_ucontext uc; > struct target_siginfo info; > - struct target_fpstate fpstate QEMU_ALIGNED(16); > }; > -#define TARGET_RT_SIGFRAME_FXSAVE_OFFSET ( \ > - offsetof(struct rt_sigframe, fpstate) + TARGET_FPSTATE_FXSAVE_OFFSET) > #endif > > /* > * Set up a signal frame. > */ > > -static void xsave_sigcontext(CPUX86State *env, struct target_fpstate_fxsave *fxsave, > +static void xsave_sigcontext(CPUX86State *env, > + struct target_fpstate_fxsave *fxsave, > abi_ulong fxsave_addr) > { > if (!(env->features[FEAT_1_ECX] & CPUID_EXT_XSAVE)) { > @@ -266,8 +251,9 @@ static void xsave_sigcontext(CPUX86State *env, struct target_fpstate_fxsave *fxs > } > > static void setup_sigcontext(struct target_sigcontext *sc, > - struct target_fpstate *fpstate, CPUX86State *env, abi_ulong mask, > - abi_ulong fpstate_addr) > + struct target_fpstate *fpstate, > + CPUX86State *env, abi_ulong mask, > + abi_ulong fpstate_addr) > { > CPUState *cs = env_cpu(env); > #ifndef TARGET_X86_64 > @@ -347,10 +333,11 @@ static void setup_sigcontext(struct target_sigcontext *sc, > * Determine which stack to use.. > */ > > -static inline abi_ulong > -get_sigframe(struct target_sigaction *ka, CPUX86State *env, size_t fxsave_offset) > +static abi_ulong get_sigframe(struct target_sigaction *ka, CPUX86State *env, > + size_t *frame_size, abi_ulong *fpsave_addr) > { > - unsigned long esp; > + abi_ulong esp, orig; > + size_t fpsave_size; > > /* Default to using normal stack */ > esp = get_sp_from_cpustate(env); > @@ -371,16 +358,23 @@ get_sigframe(struct target_sigaction *ka, CPUX86State *env, size_t fxsave_offset > } > #endif > } > + orig = esp; > > - if (!(env->features[FEAT_1_EDX] & CPUID_FXSR)) { > - return (esp - (fxsave_offset + TARGET_FXSAVE_SIZE)) & -8ul; > - } else if (!(env->features[FEAT_1_ECX] & CPUID_EXT_XSAVE)) { > - return ((esp - TARGET_FXSAVE_SIZE) & -16ul) - fxsave_offset; > + if (!(env->features[FEAT_1_ECX] & CPUID_EXT_XSAVE)) { > + fpsave_size = TARGET_FXSAVE_SIZE; > + esp = ROUND_DOWN(esp - fpsave_size, 16); > } else { > - size_t xstate_size = > - xsave_area_size(env->xcr0, false) + TARGET_FP_XSTATE_MAGIC2_SIZE; > - return ((esp - xstate_size) & -64ul) - fxsave_offset; > + fpsave_size = xsave_area_size(env->xcr0, false) > + + TARGET_FP_XSTATE_MAGIC2_SIZE; > + esp = ROUND_DOWN(esp - fpsave_size, 64); > } > + *fpsave_addr = esp; > + > + esp = esp - *frame_size + sizeof(abi_ulong); > + esp = ROUND_DOWN(esp, 16) - sizeof(abi_ulong); > + > + *frame_size = orig - esp; > + return esp; > } > > #ifndef TARGET_X86_64 > @@ -405,26 +399,34 @@ void setup_frame(int sig, struct target_sigaction *ka, > target_sigset_t *set, CPUX86State *env) > { > abi_ulong frame_addr; > + abi_ulong fpstate_addr; > + size_t frame_size; > struct sigframe *frame; > + struct target_fpstate *fpstate; > int i; > > - frame_addr = get_sigframe(ka, env, TARGET_SIGFRAME_FXSAVE_OFFSET); > + frame_size = sizeof(struct sigframe); > + frame_addr = get_sigframe(ka, env, &frame_size, &fpstate_addr); > trace_user_setup_frame(env, frame_addr); > > - if (!lock_user_struct(VERIFY_WRITE, frame, frame_addr, 0)) > + frame = lock_user(VERIFY_WRITE, frame_addr, frame_size, false); > + if (!frame) { > goto give_sigsegv; > + } > + fpstate = (void *)frame + (fpstate_addr - frame_addr); > > __put_user(sig, &frame->sig); > > - setup_sigcontext(&frame->sc, &frame->fpstate, env, set->sig[0], > - frame_addr + offsetof(struct sigframe, fpstate)); > + setup_sigcontext(&frame->sc, fpstate, env, set->sig[0], fpstate_addr); > > - for(i = 1; i < TARGET_NSIG_WORDS; i++) { > + for (i = 1; i < TARGET_NSIG_WORDS; i++) { > __put_user(set->sig[i], &frame->extramask[i - 1]); > } > > - /* Set up to return from userspace. If provided, use a stub > - already in userspace. */ > + /* > + * Set up to return from userspace. > + * If provided, use a stub already in userspace. > + */ > if (ka->sa_flags & TARGET_SA_RESTORER) { > __put_user(ka->sa_restorer, &frame->pretcode); > } else { > @@ -443,11 +445,10 @@ void setup_frame(int sig, struct target_sigaction *ka, > cpu_x86_load_seg(env, R_CS, __USER_CS); > env->eflags &= ~TF_MASK; > > - unlock_user_struct(frame, frame_addr, 1); > - > + unlock_user(frame, frame_addr, frame_size); > return; > > -give_sigsegv: > + give_sigsegv: > force_sigsegv(sig); > } > #endif > @@ -458,17 +459,24 @@ void setup_rt_frame(int sig, struct target_sigaction *ka, > target_sigset_t *set, CPUX86State *env) > { > abi_ulong frame_addr; > + abi_ulong fpstate_addr; > + size_t frame_size; > #ifndef TARGET_X86_64 > abi_ulong addr; > #endif > struct rt_sigframe *frame; > + struct target_fpstate *fpstate; > int i; > > - frame_addr = get_sigframe(ka, env, TARGET_RT_SIGFRAME_FXSAVE_OFFSET); > + frame_size = sizeof(struct rt_sigframe); > + frame_addr = get_sigframe(ka, env, &frame_size, &fpstate_addr); > trace_user_setup_rt_frame(env, frame_addr); > > - if (!lock_user_struct(VERIFY_WRITE, frame, frame_addr, 0)) > + frame = lock_user(VERIFY_WRITE, frame_addr, frame_size, false); > + if (!frame) { > goto give_sigsegv; > + } > + fpstate = (void *)frame + (fpstate_addr - frame_addr); > > /* These fields are only in rt_sigframe on 32 bit */ > #ifndef TARGET_X86_64 > @@ -490,10 +498,10 @@ void setup_rt_frame(int sig, struct target_sigaction *ka, > } > __put_user(0, &frame->uc.tuc_link); > target_save_altstack(&frame->uc.tuc_stack, env); > - setup_sigcontext(&frame->uc.tuc_mcontext, &frame->fpstate, env, > - set->sig[0], frame_addr + offsetof(struct rt_sigframe, fpstate)); > + setup_sigcontext(&frame->uc.tuc_mcontext, fpstate, env, > + set->sig[0], fpstate_addr); > > - for(i = 0; i < TARGET_NSIG_WORDS; i++) { > + for (i = 0; i < TARGET_NSIG_WORDS; i++) { > __put_user(set->sig[i], &frame->uc.tuc_sigmask.sig[i]); > } > > @@ -533,15 +541,15 @@ void setup_rt_frame(int sig, struct target_sigaction *ka, > cpu_x86_load_seg(env, R_SS, __USER_DS); > env->eflags &= ~TF_MASK; > > - unlock_user_struct(frame, frame_addr, 1); > - > + unlock_user(frame, frame_addr, frame_size); > return; > > -give_sigsegv: > + give_sigsegv: > force_sigsegv(sig); > } > > -static int xrstor_sigcontext(CPUX86State *env, struct target_fpstate_fxsave *fxsave, > +static int xrstor_sigcontext(CPUX86State *env, > + struct target_fpstate_fxsave *fxsave, > abi_ulong fxsave_addr) > { > if (env->features[FEAT_1_ECX] & CPUID_EXT_XSAVE) { > diff --git a/tests/tcg/x86_64/sigstack.c b/tests/tcg/x86_64/sigstack.c > new file mode 100644 > index 0000000000..06cb847569 > --- /dev/null > +++ b/tests/tcg/x86_64/sigstack.c > @@ -0,0 +1,33 @@ > +#include <stdlib.h> > +#include <assert.h> > +#include <signal.h> > +#include <stdint.h> > + > +void __attribute__((noinline)) bar(void) > +{ > + exit(EXIT_SUCCESS); > +} > + > +void __attribute__((noinline, ms_abi)) foo(void) > +{ > + /* > + * With ms_abi, there are call-saved xmm registers, which are forced > + * to the stack around the call to sysv_abi bar(). If the signal > + * stack frame is not properly aligned, movaps will raise #GP. > + */ > + bar(); > +} > + > +void sighandler(int num) > +{ > + void* sp = __builtin_dwarf_cfa(); > + assert((uintptr_t)sp % 16 == 0); > + foo(); > +} > + > +int main(void) > +{ > + signal(SIGUSR1, sighandler); > + raise(SIGUSR1); > + abort(); > +} > diff --git a/tests/tcg/x86_64/Makefile.target b/tests/tcg/x86_64/Makefile.target > index e64aab1b81..d961599f64 100644 > --- a/tests/tcg/x86_64/Makefile.target > +++ b/tests/tcg/x86_64/Makefile.target > @@ -13,6 +13,7 @@ X86_64_TESTS += vsyscall > X86_64_TESTS += noexec > X86_64_TESTS += cmpxchg > X86_64_TESTS += adox > +X86_64_TESTS += sigstack > TESTS=$(MULTIARCH_TESTS) $(X86_64_TESTS) test-x86_64 > else > TESTS=$(MULTIARCH_TESTS)
Ping 2. On 6/20/23 15:26, Richard Henderson wrote: > Ping. > > On 5/24/23 07:46, Richard Henderson wrote: >> The beginning of the structure, with pretaddr, should be just below >> 16-byte alignment. Disconnect fpstate from sigframe, just like the >> kernel does. >> >> Signed-off-by: Richard Henderson <richard.henderson@linaro.org> >> --- >> linux-user/i386/signal.c | 104 +++++++++++++++++-------------- >> tests/tcg/x86_64/sigstack.c | 33 ++++++++++ >> tests/tcg/x86_64/Makefile.target | 1 + >> 3 files changed, 90 insertions(+), 48 deletions(-) >> create mode 100644 tests/tcg/x86_64/sigstack.c >> >> diff --git a/linux-user/i386/signal.c b/linux-user/i386/signal.c >> index 60fa07d6f9..c49467de78 100644 >> --- a/linux-user/i386/signal.c >> +++ b/linux-user/i386/signal.c >> @@ -191,16 +191,7 @@ struct sigframe { >> struct target_fpstate fpstate_unused; >> abi_ulong extramask[TARGET_NSIG_WORDS-1]; >> char retcode[8]; >> - >> - /* >> - * This field will be 16-byte aligned in memory. Applying QEMU_ALIGNED >> - * to it ensures that the base of the frame has an appropriate alignment >> - * too. >> - */ >> - struct target_fpstate fpstate QEMU_ALIGNED(8); >> }; >> -#define TARGET_SIGFRAME_FXSAVE_OFFSET ( \ >> - offsetof(struct sigframe, fpstate) + TARGET_FPSTATE_FXSAVE_OFFSET) >> struct rt_sigframe { >> abi_ulong pretcode; >> @@ -210,27 +201,21 @@ struct rt_sigframe { >> struct target_siginfo info; >> struct target_ucontext uc; >> char retcode[8]; >> - struct target_fpstate fpstate QEMU_ALIGNED(8); >> }; >> -#define TARGET_RT_SIGFRAME_FXSAVE_OFFSET ( \ >> - offsetof(struct rt_sigframe, fpstate) + TARGET_FPSTATE_FXSAVE_OFFSET) >> #else >> - >> struct rt_sigframe { >> abi_ulong pretcode; >> struct target_ucontext uc; >> struct target_siginfo info; >> - struct target_fpstate fpstate QEMU_ALIGNED(16); >> }; >> -#define TARGET_RT_SIGFRAME_FXSAVE_OFFSET ( \ >> - offsetof(struct rt_sigframe, fpstate) + TARGET_FPSTATE_FXSAVE_OFFSET) >> #endif >> /* >> * Set up a signal frame. >> */ >> -static void xsave_sigcontext(CPUX86State *env, struct target_fpstate_fxsave *fxsave, >> +static void xsave_sigcontext(CPUX86State *env, >> + struct target_fpstate_fxsave *fxsave, >> abi_ulong fxsave_addr) >> { >> if (!(env->features[FEAT_1_ECX] & CPUID_EXT_XSAVE)) { >> @@ -266,8 +251,9 @@ static void xsave_sigcontext(CPUX86State *env, struct >> target_fpstate_fxsave *fxs >> } >> static void setup_sigcontext(struct target_sigcontext *sc, >> - struct target_fpstate *fpstate, CPUX86State *env, abi_ulong mask, >> - abi_ulong fpstate_addr) >> + struct target_fpstate *fpstate, >> + CPUX86State *env, abi_ulong mask, >> + abi_ulong fpstate_addr) >> { >> CPUState *cs = env_cpu(env); >> #ifndef TARGET_X86_64 >> @@ -347,10 +333,11 @@ static void setup_sigcontext(struct target_sigcontext *sc, >> * Determine which stack to use.. >> */ >> -static inline abi_ulong >> -get_sigframe(struct target_sigaction *ka, CPUX86State *env, size_t fxsave_offset) >> +static abi_ulong get_sigframe(struct target_sigaction *ka, CPUX86State *env, >> + size_t *frame_size, abi_ulong *fpsave_addr) >> { >> - unsigned long esp; >> + abi_ulong esp, orig; >> + size_t fpsave_size; >> /* Default to using normal stack */ >> esp = get_sp_from_cpustate(env); >> @@ -371,16 +358,23 @@ get_sigframe(struct target_sigaction *ka, CPUX86State *env, size_t >> fxsave_offset >> } >> #endif >> } >> + orig = esp; >> - if (!(env->features[FEAT_1_EDX] & CPUID_FXSR)) { >> - return (esp - (fxsave_offset + TARGET_FXSAVE_SIZE)) & -8ul; >> - } else if (!(env->features[FEAT_1_ECX] & CPUID_EXT_XSAVE)) { >> - return ((esp - TARGET_FXSAVE_SIZE) & -16ul) - fxsave_offset; >> + if (!(env->features[FEAT_1_ECX] & CPUID_EXT_XSAVE)) { >> + fpsave_size = TARGET_FXSAVE_SIZE; >> + esp = ROUND_DOWN(esp - fpsave_size, 16); >> } else { >> - size_t xstate_size = >> - xsave_area_size(env->xcr0, false) + TARGET_FP_XSTATE_MAGIC2_SIZE; >> - return ((esp - xstate_size) & -64ul) - fxsave_offset; >> + fpsave_size = xsave_area_size(env->xcr0, false) >> + + TARGET_FP_XSTATE_MAGIC2_SIZE; >> + esp = ROUND_DOWN(esp - fpsave_size, 64); >> } >> + *fpsave_addr = esp; >> + >> + esp = esp - *frame_size + sizeof(abi_ulong); >> + esp = ROUND_DOWN(esp, 16) - sizeof(abi_ulong); >> + >> + *frame_size = orig - esp; >> + return esp; >> } >> #ifndef TARGET_X86_64 >> @@ -405,26 +399,34 @@ void setup_frame(int sig, struct target_sigaction *ka, >> target_sigset_t *set, CPUX86State *env) >> { >> abi_ulong frame_addr; >> + abi_ulong fpstate_addr; >> + size_t frame_size; >> struct sigframe *frame; >> + struct target_fpstate *fpstate; >> int i; >> - frame_addr = get_sigframe(ka, env, TARGET_SIGFRAME_FXSAVE_OFFSET); >> + frame_size = sizeof(struct sigframe); >> + frame_addr = get_sigframe(ka, env, &frame_size, &fpstate_addr); >> trace_user_setup_frame(env, frame_addr); >> - if (!lock_user_struct(VERIFY_WRITE, frame, frame_addr, 0)) >> + frame = lock_user(VERIFY_WRITE, frame_addr, frame_size, false); >> + if (!frame) { >> goto give_sigsegv; >> + } >> + fpstate = (void *)frame + (fpstate_addr - frame_addr); >> __put_user(sig, &frame->sig); >> - setup_sigcontext(&frame->sc, &frame->fpstate, env, set->sig[0], >> - frame_addr + offsetof(struct sigframe, fpstate)); >> + setup_sigcontext(&frame->sc, fpstate, env, set->sig[0], fpstate_addr); >> - for(i = 1; i < TARGET_NSIG_WORDS; i++) { >> + for (i = 1; i < TARGET_NSIG_WORDS; i++) { >> __put_user(set->sig[i], &frame->extramask[i - 1]); >> } >> - /* Set up to return from userspace. If provided, use a stub >> - already in userspace. */ >> + /* >> + * Set up to return from userspace. >> + * If provided, use a stub already in userspace. >> + */ >> if (ka->sa_flags & TARGET_SA_RESTORER) { >> __put_user(ka->sa_restorer, &frame->pretcode); >> } else { >> @@ -443,11 +445,10 @@ void setup_frame(int sig, struct target_sigaction *ka, >> cpu_x86_load_seg(env, R_CS, __USER_CS); >> env->eflags &= ~TF_MASK; >> - unlock_user_struct(frame, frame_addr, 1); >> - >> + unlock_user(frame, frame_addr, frame_size); >> return; >> -give_sigsegv: >> + give_sigsegv: >> force_sigsegv(sig); >> } >> #endif >> @@ -458,17 +459,24 @@ void setup_rt_frame(int sig, struct target_sigaction *ka, >> target_sigset_t *set, CPUX86State *env) >> { >> abi_ulong frame_addr; >> + abi_ulong fpstate_addr; >> + size_t frame_size; >> #ifndef TARGET_X86_64 >> abi_ulong addr; >> #endif >> struct rt_sigframe *frame; >> + struct target_fpstate *fpstate; >> int i; >> - frame_addr = get_sigframe(ka, env, TARGET_RT_SIGFRAME_FXSAVE_OFFSET); >> + frame_size = sizeof(struct rt_sigframe); >> + frame_addr = get_sigframe(ka, env, &frame_size, &fpstate_addr); >> trace_user_setup_rt_frame(env, frame_addr); >> - if (!lock_user_struct(VERIFY_WRITE, frame, frame_addr, 0)) >> + frame = lock_user(VERIFY_WRITE, frame_addr, frame_size, false); >> + if (!frame) { >> goto give_sigsegv; >> + } >> + fpstate = (void *)frame + (fpstate_addr - frame_addr); >> /* These fields are only in rt_sigframe on 32 bit */ >> #ifndef TARGET_X86_64 >> @@ -490,10 +498,10 @@ void setup_rt_frame(int sig, struct target_sigaction *ka, >> } >> __put_user(0, &frame->uc.tuc_link); >> target_save_altstack(&frame->uc.tuc_stack, env); >> - setup_sigcontext(&frame->uc.tuc_mcontext, &frame->fpstate, env, >> - set->sig[0], frame_addr + offsetof(struct rt_sigframe, fpstate)); >> + setup_sigcontext(&frame->uc.tuc_mcontext, fpstate, env, >> + set->sig[0], fpstate_addr); >> - for(i = 0; i < TARGET_NSIG_WORDS; i++) { >> + for (i = 0; i < TARGET_NSIG_WORDS; i++) { >> __put_user(set->sig[i], &frame->uc.tuc_sigmask.sig[i]); >> } >> @@ -533,15 +541,15 @@ void setup_rt_frame(int sig, struct target_sigaction *ka, >> cpu_x86_load_seg(env, R_SS, __USER_DS); >> env->eflags &= ~TF_MASK; >> - unlock_user_struct(frame, frame_addr, 1); >> - >> + unlock_user(frame, frame_addr, frame_size); >> return; >> -give_sigsegv: >> + give_sigsegv: >> force_sigsegv(sig); >> } >> -static int xrstor_sigcontext(CPUX86State *env, struct target_fpstate_fxsave *fxsave, >> +static int xrstor_sigcontext(CPUX86State *env, >> + struct target_fpstate_fxsave *fxsave, >> abi_ulong fxsave_addr) >> { >> if (env->features[FEAT_1_ECX] & CPUID_EXT_XSAVE) { >> diff --git a/tests/tcg/x86_64/sigstack.c b/tests/tcg/x86_64/sigstack.c >> new file mode 100644 >> index 0000000000..06cb847569 >> --- /dev/null >> +++ b/tests/tcg/x86_64/sigstack.c >> @@ -0,0 +1,33 @@ >> +#include <stdlib.h> >> +#include <assert.h> >> +#include <signal.h> >> +#include <stdint.h> >> + >> +void __attribute__((noinline)) bar(void) >> +{ >> + exit(EXIT_SUCCESS); >> +} >> + >> +void __attribute__((noinline, ms_abi)) foo(void) >> +{ >> + /* >> + * With ms_abi, there are call-saved xmm registers, which are forced >> + * to the stack around the call to sysv_abi bar(). If the signal >> + * stack frame is not properly aligned, movaps will raise #GP. >> + */ >> + bar(); >> +} >> + >> +void sighandler(int num) >> +{ >> + void* sp = __builtin_dwarf_cfa(); >> + assert((uintptr_t)sp % 16 == 0); >> + foo(); >> +} >> + >> +int main(void) >> +{ >> + signal(SIGUSR1, sighandler); >> + raise(SIGUSR1); >> + abort(); >> +} >> diff --git a/tests/tcg/x86_64/Makefile.target b/tests/tcg/x86_64/Makefile.target >> index e64aab1b81..d961599f64 100644 >> --- a/tests/tcg/x86_64/Makefile.target >> +++ b/tests/tcg/x86_64/Makefile.target >> @@ -13,6 +13,7 @@ X86_64_TESTS += vsyscall >> X86_64_TESTS += noexec >> X86_64_TESTS += cmpxchg >> X86_64_TESTS += adox >> +X86_64_TESTS += sigstack >> TESTS=$(MULTIARCH_TESTS) $(X86_64_TESTS) test-x86_64 >> else >> TESTS=$(MULTIARCH_TESTS) >
30.06.2023 20:53, Richard Henderson wrote: > Ping 2. > > On 6/20/23 15:26, Richard Henderson wrote: >> Ping. >> >> On 5/24/23 07:46, Richard Henderson wrote: >>> The beginning of the structure, with pretaddr, should be just below >>> 16-byte alignment. Disconnect fpstate from sigframe, just like the >>> kernel does. This smells like a -stable material too (I tagged it "stable" in my inbox a month ago already), as it is fixing real bug which people are hitting. /mjt
30.06.2023 20:53, Richard Henderson wrote: > Ping 2. > > On 6/20/23 15:26, Richard Henderson wrote: >> Ping. >> >> On 5/24/23 07:46, Richard Henderson wrote: >>> The beginning of the structure, with pretaddr, should be just below >>> 16-byte alignment. Disconnect fpstate from sigframe, just like the >>> kernel does. Whom we're pinging here? :) Ping 3 ;) (This is https://gitlab.com/qemu-project/qemu/-/issues/1648 and is a -stable material too, it seems) /mjt
On 8/5/23 14:56, Michael Tokarev wrote: > 30.06.2023 20:53, Richard Henderson wrote: >> Ping 2. >> >> On 6/20/23 15:26, Richard Henderson wrote: >>> Ping. >>> >>> On 5/24/23 07:46, Richard Henderson wrote: >>>> The beginning of the structure, with pretaddr, should be just below >>>> 16-byte alignment. Disconnect fpstate from sigframe, just like the >>>> kernel does. > > Whom we're pinging here? :) > Ping 3 ;) > > (This is https://gitlab.com/qemu-project/qemu/-/issues/1648 and is a > -stable material too, it seems) In the month since, I've discovered that fpstate needs even more work. This is extremely fiddly stuff, and we need a complete rewrite to match the kernel and the required alignments. r~
24.05.2023 08:46, Richard Henderson: > The beginning of the structure, with pretaddr, should be just below > 16-byte alignment. Disconnect fpstate from sigframe, just like the > kernel does. Resolves: https://gitlab.com/qemu-project/qemu/-/issues/1648 Ping? Has this been forgotten? It's been 5 months already.. /mjt
On 10/25/23 23:35, Michael Tokarev wrote: > 24.05.2023 08:46, Richard Henderson: >> The beginning of the structure, with pretaddr, should be just below >> 16-byte alignment. Disconnect fpstate from sigframe, just like the >> kernel does. > > Resolves: https://gitlab.com/qemu-project/qemu/-/issues/1648 > > Ping? Has this been forgotten? It's been 5 months already.. I have not returned to this problem yet. r~
diff --git a/linux-user/i386/signal.c b/linux-user/i386/signal.c index 60fa07d6f9..c49467de78 100644 --- a/linux-user/i386/signal.c +++ b/linux-user/i386/signal.c @@ -191,16 +191,7 @@ struct sigframe { struct target_fpstate fpstate_unused; abi_ulong extramask[TARGET_NSIG_WORDS-1]; char retcode[8]; - - /* - * This field will be 16-byte aligned in memory. Applying QEMU_ALIGNED - * to it ensures that the base of the frame has an appropriate alignment - * too. - */ - struct target_fpstate fpstate QEMU_ALIGNED(8); }; -#define TARGET_SIGFRAME_FXSAVE_OFFSET ( \ - offsetof(struct sigframe, fpstate) + TARGET_FPSTATE_FXSAVE_OFFSET) struct rt_sigframe { abi_ulong pretcode; @@ -210,27 +201,21 @@ struct rt_sigframe { struct target_siginfo info; struct target_ucontext uc; char retcode[8]; - struct target_fpstate fpstate QEMU_ALIGNED(8); }; -#define TARGET_RT_SIGFRAME_FXSAVE_OFFSET ( \ - offsetof(struct rt_sigframe, fpstate) + TARGET_FPSTATE_FXSAVE_OFFSET) #else - struct rt_sigframe { abi_ulong pretcode; struct target_ucontext uc; struct target_siginfo info; - struct target_fpstate fpstate QEMU_ALIGNED(16); }; -#define TARGET_RT_SIGFRAME_FXSAVE_OFFSET ( \ - offsetof(struct rt_sigframe, fpstate) + TARGET_FPSTATE_FXSAVE_OFFSET) #endif /* * Set up a signal frame. */ -static void xsave_sigcontext(CPUX86State *env, struct target_fpstate_fxsave *fxsave, +static void xsave_sigcontext(CPUX86State *env, + struct target_fpstate_fxsave *fxsave, abi_ulong fxsave_addr) { if (!(env->features[FEAT_1_ECX] & CPUID_EXT_XSAVE)) { @@ -266,8 +251,9 @@ static void xsave_sigcontext(CPUX86State *env, struct target_fpstate_fxsave *fxs } static void setup_sigcontext(struct target_sigcontext *sc, - struct target_fpstate *fpstate, CPUX86State *env, abi_ulong mask, - abi_ulong fpstate_addr) + struct target_fpstate *fpstate, + CPUX86State *env, abi_ulong mask, + abi_ulong fpstate_addr) { CPUState *cs = env_cpu(env); #ifndef TARGET_X86_64 @@ -347,10 +333,11 @@ static void setup_sigcontext(struct target_sigcontext *sc, * Determine which stack to use.. */ -static inline abi_ulong -get_sigframe(struct target_sigaction *ka, CPUX86State *env, size_t fxsave_offset) +static abi_ulong get_sigframe(struct target_sigaction *ka, CPUX86State *env, + size_t *frame_size, abi_ulong *fpsave_addr) { - unsigned long esp; + abi_ulong esp, orig; + size_t fpsave_size; /* Default to using normal stack */ esp = get_sp_from_cpustate(env); @@ -371,16 +358,23 @@ get_sigframe(struct target_sigaction *ka, CPUX86State *env, size_t fxsave_offset } #endif } + orig = esp; - if (!(env->features[FEAT_1_EDX] & CPUID_FXSR)) { - return (esp - (fxsave_offset + TARGET_FXSAVE_SIZE)) & -8ul; - } else if (!(env->features[FEAT_1_ECX] & CPUID_EXT_XSAVE)) { - return ((esp - TARGET_FXSAVE_SIZE) & -16ul) - fxsave_offset; + if (!(env->features[FEAT_1_ECX] & CPUID_EXT_XSAVE)) { + fpsave_size = TARGET_FXSAVE_SIZE; + esp = ROUND_DOWN(esp - fpsave_size, 16); } else { - size_t xstate_size = - xsave_area_size(env->xcr0, false) + TARGET_FP_XSTATE_MAGIC2_SIZE; - return ((esp - xstate_size) & -64ul) - fxsave_offset; + fpsave_size = xsave_area_size(env->xcr0, false) + + TARGET_FP_XSTATE_MAGIC2_SIZE; + esp = ROUND_DOWN(esp - fpsave_size, 64); } + *fpsave_addr = esp; + + esp = esp - *frame_size + sizeof(abi_ulong); + esp = ROUND_DOWN(esp, 16) - sizeof(abi_ulong); + + *frame_size = orig - esp; + return esp; } #ifndef TARGET_X86_64 @@ -405,26 +399,34 @@ void setup_frame(int sig, struct target_sigaction *ka, target_sigset_t *set, CPUX86State *env) { abi_ulong frame_addr; + abi_ulong fpstate_addr; + size_t frame_size; struct sigframe *frame; + struct target_fpstate *fpstate; int i; - frame_addr = get_sigframe(ka, env, TARGET_SIGFRAME_FXSAVE_OFFSET); + frame_size = sizeof(struct sigframe); + frame_addr = get_sigframe(ka, env, &frame_size, &fpstate_addr); trace_user_setup_frame(env, frame_addr); - if (!lock_user_struct(VERIFY_WRITE, frame, frame_addr, 0)) + frame = lock_user(VERIFY_WRITE, frame_addr, frame_size, false); + if (!frame) { goto give_sigsegv; + } + fpstate = (void *)frame + (fpstate_addr - frame_addr); __put_user(sig, &frame->sig); - setup_sigcontext(&frame->sc, &frame->fpstate, env, set->sig[0], - frame_addr + offsetof(struct sigframe, fpstate)); + setup_sigcontext(&frame->sc, fpstate, env, set->sig[0], fpstate_addr); - for(i = 1; i < TARGET_NSIG_WORDS; i++) { + for (i = 1; i < TARGET_NSIG_WORDS; i++) { __put_user(set->sig[i], &frame->extramask[i - 1]); } - /* Set up to return from userspace. If provided, use a stub - already in userspace. */ + /* + * Set up to return from userspace. + * If provided, use a stub already in userspace. + */ if (ka->sa_flags & TARGET_SA_RESTORER) { __put_user(ka->sa_restorer, &frame->pretcode); } else { @@ -443,11 +445,10 @@ void setup_frame(int sig, struct target_sigaction *ka, cpu_x86_load_seg(env, R_CS, __USER_CS); env->eflags &= ~TF_MASK; - unlock_user_struct(frame, frame_addr, 1); - + unlock_user(frame, frame_addr, frame_size); return; -give_sigsegv: + give_sigsegv: force_sigsegv(sig); } #endif @@ -458,17 +459,24 @@ void setup_rt_frame(int sig, struct target_sigaction *ka, target_sigset_t *set, CPUX86State *env) { abi_ulong frame_addr; + abi_ulong fpstate_addr; + size_t frame_size; #ifndef TARGET_X86_64 abi_ulong addr; #endif struct rt_sigframe *frame; + struct target_fpstate *fpstate; int i; - frame_addr = get_sigframe(ka, env, TARGET_RT_SIGFRAME_FXSAVE_OFFSET); + frame_size = sizeof(struct rt_sigframe); + frame_addr = get_sigframe(ka, env, &frame_size, &fpstate_addr); trace_user_setup_rt_frame(env, frame_addr); - if (!lock_user_struct(VERIFY_WRITE, frame, frame_addr, 0)) + frame = lock_user(VERIFY_WRITE, frame_addr, frame_size, false); + if (!frame) { goto give_sigsegv; + } + fpstate = (void *)frame + (fpstate_addr - frame_addr); /* These fields are only in rt_sigframe on 32 bit */ #ifndef TARGET_X86_64 @@ -490,10 +498,10 @@ void setup_rt_frame(int sig, struct target_sigaction *ka, } __put_user(0, &frame->uc.tuc_link); target_save_altstack(&frame->uc.tuc_stack, env); - setup_sigcontext(&frame->uc.tuc_mcontext, &frame->fpstate, env, - set->sig[0], frame_addr + offsetof(struct rt_sigframe, fpstate)); + setup_sigcontext(&frame->uc.tuc_mcontext, fpstate, env, + set->sig[0], fpstate_addr); - for(i = 0; i < TARGET_NSIG_WORDS; i++) { + for (i = 0; i < TARGET_NSIG_WORDS; i++) { __put_user(set->sig[i], &frame->uc.tuc_sigmask.sig[i]); } @@ -533,15 +541,15 @@ void setup_rt_frame(int sig, struct target_sigaction *ka, cpu_x86_load_seg(env, R_SS, __USER_DS); env->eflags &= ~TF_MASK; - unlock_user_struct(frame, frame_addr, 1); - + unlock_user(frame, frame_addr, frame_size); return; -give_sigsegv: + give_sigsegv: force_sigsegv(sig); } -static int xrstor_sigcontext(CPUX86State *env, struct target_fpstate_fxsave *fxsave, +static int xrstor_sigcontext(CPUX86State *env, + struct target_fpstate_fxsave *fxsave, abi_ulong fxsave_addr) { if (env->features[FEAT_1_ECX] & CPUID_EXT_XSAVE) { diff --git a/tests/tcg/x86_64/sigstack.c b/tests/tcg/x86_64/sigstack.c new file mode 100644 index 0000000000..06cb847569 --- /dev/null +++ b/tests/tcg/x86_64/sigstack.c @@ -0,0 +1,33 @@ +#include <stdlib.h> +#include <assert.h> +#include <signal.h> +#include <stdint.h> + +void __attribute__((noinline)) bar(void) +{ + exit(EXIT_SUCCESS); +} + +void __attribute__((noinline, ms_abi)) foo(void) +{ + /* + * With ms_abi, there are call-saved xmm registers, which are forced + * to the stack around the call to sysv_abi bar(). If the signal + * stack frame is not properly aligned, movaps will raise #GP. + */ + bar(); +} + +void sighandler(int num) +{ + void* sp = __builtin_dwarf_cfa(); + assert((uintptr_t)sp % 16 == 0); + foo(); +} + +int main(void) +{ + signal(SIGUSR1, sighandler); + raise(SIGUSR1); + abort(); +} diff --git a/tests/tcg/x86_64/Makefile.target b/tests/tcg/x86_64/Makefile.target index e64aab1b81..d961599f64 100644 --- a/tests/tcg/x86_64/Makefile.target +++ b/tests/tcg/x86_64/Makefile.target @@ -13,6 +13,7 @@ X86_64_TESTS += vsyscall X86_64_TESTS += noexec X86_64_TESTS += cmpxchg X86_64_TESTS += adox +X86_64_TESTS += sigstack TESTS=$(MULTIARCH_TESTS) $(X86_64_TESTS) test-x86_64 else TESTS=$(MULTIARCH_TESTS)
The beginning of the structure, with pretaddr, should be just below 16-byte alignment. Disconnect fpstate from sigframe, just like the kernel does. Signed-off-by: Richard Henderson <richard.henderson@linaro.org> --- linux-user/i386/signal.c | 104 +++++++++++++++++-------------- tests/tcg/x86_64/sigstack.c | 33 ++++++++++ tests/tcg/x86_64/Makefile.target | 1 + 3 files changed, 90 insertions(+), 48 deletions(-) create mode 100644 tests/tcg/x86_64/sigstack.c