| Message ID | 20210618192951.125651-8-richard.henderson@linaro.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | linux-user: Move signal trampolines to new page | expand |
On 6/18/21 9:29 PM, Richard Henderson wrote: > Split out setup_sigreturn so that we can continue to > initialize the words on the stack, as documented. > However, use the off-stack trampoline. > > Cc: Edgar E. Iglesias <edgar.iglesias@gmail.com> > Signed-off-by: Richard Henderson <richard.henderson@linaro.org> > --- > linux-user/cris/target_signal.h | 2 ++ > linux-user/cris/signal.c | 29 +++++++++++++++++++++-------- > 2 files changed, 23 insertions(+), 8 deletions(-) Nitpicking, 6 -> 3 * 2? :) Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
On 6/19/21 2:33 AM, Philippe Mathieu-Daudé wrote: > On 6/18/21 9:29 PM, Richard Henderson wrote: >> Split out setup_sigreturn so that we can continue to >> initialize the words on the stack, as documented. >> However, use the off-stack trampoline. >> >> Cc: Edgar E. Iglesias <edgar.iglesias@gmail.com> >> Signed-off-by: Richard Henderson <richard.henderson@linaro.org> >> --- >> linux-user/cris/target_signal.h | 2 ++ >> linux-user/cris/signal.c | 29 +++++++++++++++++++++-------- >> 2 files changed, 23 insertions(+), 8 deletions(-) > > Nitpicking, 6 -> 3 * 2? :) Elsewhere I have used <bytes-per-tramp> * 2 if we have two trampolines, not <bytes-per-insn> * <n-insns>. r~ > > Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org> >
On 6/19/21 2:55 PM, Richard Henderson wrote: > On 6/19/21 2:33 AM, Philippe Mathieu-Daudé wrote: >> On 6/18/21 9:29 PM, Richard Henderson wrote: >>> Split out setup_sigreturn so that we can continue to >>> initialize the words on the stack, as documented. >>> However, use the off-stack trampoline. >>> >>> Cc: Edgar E. Iglesias <edgar.iglesias@gmail.com> >>> Signed-off-by: Richard Henderson <richard.henderson@linaro.org> >>> --- >>> linux-user/cris/target_signal.h | 2 ++ >>> linux-user/cris/signal.c | 29 +++++++++++++++++++++-------- >>> 2 files changed, 23 insertions(+), 8 deletions(-) >> >> Nitpicking, 6 -> 3 * 2? :) > > Elsewhere I have used <bytes-per-tramp> * 2 if we have two trampolines, > not <bytes-per-insn> * <n-insns>. Oh, OK :) >> >> Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
diff --git a/linux-user/cris/target_signal.h b/linux-user/cris/target_signal.h index 495a142896..83a5155507 100644 --- a/linux-user/cris/target_signal.h +++ b/linux-user/cris/target_signal.h @@ -22,4 +22,6 @@ typedef struct target_sigaltstack { #include "../generic/signal.h" #define TARGET_ARCH_HAS_SETUP_FRAME +#define TARGET_ARCH_HAS_SIGTRAMP_PAGE 1 + #endif /* CRIS_TARGET_SIGNAL_H */ diff --git a/linux-user/cris/signal.c b/linux-user/cris/signal.c index 1e02194377..9dad50f31f 100644 --- a/linux-user/cris/signal.c +++ b/linux-user/cris/signal.c @@ -96,6 +96,14 @@ static abi_ulong get_sigframe(CPUCRISState *env, int framesize) return sp - framesize; } +static void setup_sigreturn(uint16_t *retcode) +{ + /* This is movu.w __NR_sigreturn, r9; break 13; */ + __put_user(0x9c5f, retcode + 0); + __put_user(TARGET_NR_sigreturn, retcode + 1); + __put_user(0xe93d, retcode + 2); +} + void setup_frame(int sig, struct target_sigaction *ka, target_sigset_t *set, CPUCRISState *env) { @@ -111,14 +119,8 @@ void setup_frame(int sig, struct target_sigaction *ka, /* * The CRIS signal return trampoline. A real linux/CRIS kernel doesn't * use this trampoline anymore but it sets it up for GDB. - * In QEMU, using the trampoline simplifies things a bit so we use it. - * - * This is movu.w __NR_sigreturn, r9; break 13; */ - __put_user(0x9c5f, frame->retcode+0); - __put_user(TARGET_NR_sigreturn, - frame->retcode + 1); - __put_user(0xe93d, frame->retcode + 2); + setup_sigreturn(frame->retcode); /* Save the mask. */ __put_user(set->sig[0], &frame->sc.oldmask); @@ -134,7 +136,7 @@ void setup_frame(int sig, struct target_sigaction *ka, env->regs[10] = sig; env->pc = (unsigned long) ka->_sa_handler; /* Link SRP so the guest returns through the trampoline. */ - env->pregs[PR_SRP] = frame_addr + offsetof(typeof(*frame), retcode); + env->pregs[PR_SRP] = default_sigreturn; unlock_user_struct(frame, frame_addr, 1); return; @@ -186,3 +188,14 @@ long do_rt_sigreturn(CPUCRISState *env) qemu_log_mask(LOG_UNIMP, "do_rt_sigreturn: not implemented\n"); return -TARGET_ENOSYS; } + +void setup_sigtramp(abi_ulong sigtramp_page) +{ + uint16_t *tramp = lock_user(VERIFY_WRITE, sigtramp_page, 6, 0); + assert(tramp != NULL); + + default_sigreturn = sigtramp_page; + setup_sigreturn(tramp); + + unlock_user(tramp, sigtramp_page, 6); +}
Split out setup_sigreturn so that we can continue to initialize the words on the stack, as documented. However, use the off-stack trampoline. Cc: Edgar E. Iglesias <edgar.iglesias@gmail.com> Signed-off-by: Richard Henderson <richard.henderson@linaro.org> --- linux-user/cris/target_signal.h | 2 ++ linux-user/cris/signal.c | 29 +++++++++++++++++++++-------- 2 files changed, 23 insertions(+), 8 deletions(-)