[PATCH 0/2] linux-user/microblaze: update signal handling

[PATCH 0/2] linux-user/microblaze: update signal handling

[Richard Henderson]

The linux microblaze port only implements rt signal handing,
not the old style.  This allows our linux-test to pass for mb,
if you have a cross-compiler available for the build.


r~


Richard Henderson (2):
  linux-user/microblaze: Implement rt signal frames
  linux-user/microblaze: Remove non-rt signal frames

 linux-user/microblaze/target_signal.h |   1 -
 linux-user/microblaze/signal.c        | 186 ++++++++++++--------------
 2 files changed, 83 insertions(+), 104 deletions(-)

-- 
2.25.1

[PATCH 1/2] linux-user/microblaze: Implement rt signal frames

[Richard Henderson]

Allows microblaze to pass tests/tcg/multiarch/linux-test.c.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
 linux-user/microblaze/signal.c | 91 ++++++++++++++++++++++++++++++----
 1 file changed, 82 insertions(+), 9 deletions(-)

diff --git a/linux-user/microblaze/signal.c b/linux-user/microblaze/signal.c
index b4eeef4673..3d316a22f1 100644
--- a/linux-user/microblaze/signal.c
+++ b/linux-user/microblaze/signal.c
@@ -35,9 +35,9 @@ struct target_stack_t {
 struct target_ucontext {
     abi_ulong tuc_flags;
     abi_ulong tuc_link;
-    struct target_stack_t tuc_stack;
+    target_stack_t tuc_stack;
     struct target_sigcontext tuc_mcontext;
-    uint32_t tuc_extramask[TARGET_NSIG_WORDS - 1];
+    target_sigset_t tuc_sigmask;
 };
 
 /* Signal frames. */
@@ -47,9 +47,9 @@ struct target_signal_frame {
     uint32_t tramp[2];
 };
 
-struct rt_signal_frame {
-    siginfo_t info;
-    ucontext_t uc;
+struct target_rt_sigframe {
+    target_siginfo_t info;
+    struct target_ucontext uc;
     uint32_t tramp[2];
 };
 
@@ -200,7 +200,55 @@ void setup_rt_frame(int sig, struct target_sigaction *ka,
                     target_siginfo_t *info,
                     target_sigset_t *set, CPUMBState *env)
 {
-    qemu_log_mask(LOG_UNIMP, "setup_rt_frame: not implemented\n");
+    struct target_rt_sigframe *frame;
+    abi_ulong frame_addr;
+
+    frame_addr = get_sigframe(ka, env, sizeof *frame);
+    trace_user_setup_rt_frame(env, frame_addr);
+
+    if (!lock_user_struct(VERIFY_WRITE, frame, frame_addr, 0)) {
+        force_sigsegv(sig);
+        return;
+    }
+
+    tswap_siginfo(&frame->info, info);
+
+    __put_user(0, &frame->uc.tuc_flags);
+    __put_user(0, &frame->uc.tuc_link);
+
+    target_save_altstack(&frame->uc.tuc_stack, env);
+    setup_sigcontext(&frame->uc.tuc_mcontext, env);
+
+    for (int i = 0; i < TARGET_NSIG_WORDS; i++) {
+        __put_user(set->sig[i], &frame->uc.tuc_sigmask.sig[i]);
+    }
+
+    /* Kernel does not use SA_RESTORER. */
+
+    /* addi r12, r0, __NR_sigreturn */
+    __put_user(0x31800000U | TARGET_NR_rt_sigreturn, frame->tramp + 0);
+    /* brki r14, 0x8 */
+    __put_user(0xb9cc0008U, frame->tramp + 1);
+
+    /*
+     * Return from sighandler will jump to the tramp.
+     * Negative 8 offset because return is rtsd r15, 8
+     */
+    env->regs[15] =
+        frame_addr + offsetof(struct target_rt_sigframe, tramp) - 8;
+
+    /* Set up registers for signal handler */
+    env->regs[1] = frame_addr;
+
+    /* Signal handler args: */
+    env->regs[5] = sig;
+    env->regs[6] = frame_addr + offsetof(struct target_rt_sigframe, info);
+    env->regs[7] = frame_addr + offsetof(struct target_rt_sigframe, uc);
+
+    /* Offset to handle microblaze rtid r14, 0 */
+    env->pc = (unsigned long)ka->_sa_handler;
+
+    unlock_user_struct(frame, frame_addr, 1);
 }
 
 long do_sigreturn(CPUMBState *env)
@@ -239,7 +287,32 @@ badframe:
 
 long do_rt_sigreturn(CPUMBState *env)
 {
-    trace_user_do_rt_sigreturn(env, 0);
-    qemu_log_mask(LOG_UNIMP, "do_rt_sigreturn: not implemented\n");
-    return -TARGET_ENOSYS;
+    struct target_rt_sigframe *frame = NULL;
+    abi_ulong frame_addr = env->regs[1];
+    sigset_t set;
+
+    trace_user_do_rt_sigreturn(env, frame_addr);
+
+    if  (!lock_user_struct(VERIFY_READ, frame, frame_addr, 1)) {
+        goto badframe;
+    }
+
+    target_to_host_sigset(&set, &frame->uc.tuc_sigmask);
+    set_sigmask(&set);
+
+    restore_sigcontext(&frame->uc.tuc_mcontext, env);
+
+    if (do_sigaltstack(frame_addr +
+                       offsetof(struct target_rt_sigframe, uc.tuc_stack),
+                       0, get_sp_from_cpustate(env)) == -EFAULT) {
+        goto badframe;
+    }
+
+    unlock_user_struct(frame, frame_addr, 0);
+    return -TARGET_QEMU_ESIGRETURN;
+
+ badframe:
+    unlock_user_struct(frame, frame_addr, 0);
+    force_sig(TARGET_SIGSEGV);
+    return -TARGET_QEMU_ESIGRETURN;
 }
-- 
2.25.1

[PATCH 2/2] linux-user/microblaze: Remove non-rt signal frames

[Richard Henderson]

The microblaze kernel does not support these, and uses
only rt style signal frames.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
 linux-user/microblaze/target_signal.h |  1 -
 linux-user/microblaze/signal.c        | 97 +--------------------------
 2 files changed, 2 insertions(+), 96 deletions(-)

diff --git a/linux-user/microblaze/target_signal.h b/linux-user/microblaze/target_signal.h
index 35efd5e928..08bcf24b9d 100644
--- a/linux-user/microblaze/target_signal.h
+++ b/linux-user/microblaze/target_signal.h
@@ -21,5 +21,4 @@ typedef struct target_sigaltstack {
 
 #include "../generic/signal.h"
 
-#define TARGET_ARCH_HAS_SETUP_FRAME
 #endif /* MICROBLAZE_TARGET_SIGNAL_H */
diff --git a/linux-user/microblaze/signal.c b/linux-user/microblaze/signal.c
index 3d316a22f1..cf0707b556 100644
--- a/linux-user/microblaze/signal.c
+++ b/linux-user/microblaze/signal.c
@@ -41,12 +41,6 @@ struct target_ucontext {
 };
 
 /* Signal frames. */
-struct target_signal_frame {
-    struct target_ucontext uc;
-    uint32_t extramask[TARGET_NSIG_WORDS - 1];
-    uint32_t tramp[2];
-};
-
 struct target_rt_sigframe {
     target_siginfo_t info;
     struct target_ucontext uc;
@@ -137,65 +131,6 @@ static abi_ulong get_sigframe(struct target_sigaction *ka,
     return ((sp - frame_size) & -8UL);
 }
 
-void setup_frame(int sig, struct target_sigaction *ka,
-                 target_sigset_t *set, CPUMBState *env)
-{
-    struct target_signal_frame *frame;
-    abi_ulong frame_addr;
-    int i;
-
-    frame_addr = get_sigframe(ka, env, sizeof *frame);
-    trace_user_setup_frame(env, frame_addr);
-    if (!lock_user_struct(VERIFY_WRITE, frame, frame_addr, 0))
-        goto badframe;
-
-    /* Save the mask.  */
-    __put_user(set->sig[0], &frame->uc.tuc_mcontext.oldmask);
-
-    for(i = 1; i < TARGET_NSIG_WORDS; i++) {
-        __put_user(set->sig[i], &frame->extramask[i - 1]);
-    }
-
-    setup_sigcontext(&frame->uc.tuc_mcontext, env);
-
-    /* Set up to return from userspace. If provided, use a stub
-       already in userspace. */
-    /* minus 8 is offset to cater for "rtsd r15,8" offset */
-    if (ka->sa_flags & TARGET_SA_RESTORER) {
-        env->regs[15] = ((unsigned long)ka->sa_restorer)-8;
-    } else {
-        uint32_t t;
-        /* Note, these encodings are _big endian_! */
-        /* addi r12, r0, __NR_sigreturn */
-        t = 0x31800000UL | TARGET_NR_sigreturn;
-        __put_user(t, frame->tramp + 0);
-        /* brki r14, 0x8 */
-        t = 0xb9cc0008UL;
-        __put_user(t, frame->tramp + 1);
-
-        /* Return from sighandler will jump to the tramp.
-           Negative 8 offset because return is rtsd r15, 8 */
-        env->regs[15] = frame_addr + offsetof(struct target_signal_frame, tramp)
-                                   - 8;
-    }
-
-    /* Set up registers for signal handler */
-    env->regs[1] = frame_addr;
-    /* Signal handler args: */
-    env->regs[5] = sig; /* Arg 0: signum */
-    env->regs[6] = 0;
-    /* arg 1: sigcontext */
-    env->regs[7] = frame_addr += offsetof(typeof(*frame), uc);
-
-    /* Offset of 4 to handle microblaze rtid r14, 0 */
-    env->pc = (unsigned long)ka->_sa_handler;
-
-    unlock_user_struct(frame, frame_addr, 1);
-    return;
-badframe:
-    force_sigsegv(sig);
-}
-
 void setup_rt_frame(int sig, struct target_sigaction *ka,
                     target_siginfo_t *info,
                     target_sigset_t *set, CPUMBState *env)
@@ -251,38 +186,10 @@ void setup_rt_frame(int sig, struct target_sigaction *ka,
     unlock_user_struct(frame, frame_addr, 1);
 }
 
+
 long do_sigreturn(CPUMBState *env)
 {
-    struct target_signal_frame *frame;
-    abi_ulong frame_addr;
-    target_sigset_t target_set;
-    sigset_t set;
-    int i;
-
-    frame_addr = env->regs[R_SP];
-    trace_user_do_sigreturn(env, frame_addr);
-    /* Make sure the guest isn't playing games.  */
-    if (!lock_user_struct(VERIFY_WRITE, frame, frame_addr, 1))
-        goto badframe;
-
-    /* Restore blocked signals */
-    __get_user(target_set.sig[0], &frame->uc.tuc_mcontext.oldmask);
-    for(i = 1; i < TARGET_NSIG_WORDS; i++) {
-        __get_user(target_set.sig[i], &frame->extramask[i - 1]);
-    }
-    target_to_host_sigset_internal(&set, &target_set);
-    set_sigmask(&set);
-
-    restore_sigcontext(&frame->uc.tuc_mcontext, env);
-    /* We got here through a sigreturn syscall, our path back is via an
-       rtb insn so setup r14 for that.  */
-    env->regs[14] = env->pc;
-
-    unlock_user_struct(frame, frame_addr, 0);
-    return -TARGET_QEMU_ESIGRETURN;
-badframe:
-    force_sig(TARGET_SIGSEGV);
-    return -TARGET_QEMU_ESIGRETURN;
+    return -TARGET_ENOSYS;
 }
 
 long do_rt_sigreturn(CPUMBState *env)
-- 
2.25.1

Re: [PATCH 0/2] linux-user/microblaze: update signal handling

[Edgar E. Iglesias]

On Sat, Oct 10, 2020 at 12:31:28PM -0500, Richard Henderson wrote:
> The linux microblaze port only implements rt signal handing,
> not the old style.  This allows our linux-test to pass for mb,
> if you have a cross-compiler available for the build.

Tested-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
Reviewed-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>


> 
> 
> r~
> 
> 
> Richard Henderson (2):
>   linux-user/microblaze: Implement rt signal frames
>   linux-user/microblaze: Remove non-rt signal frames
> 
>  linux-user/microblaze/target_signal.h |   1 -
>  linux-user/microblaze/signal.c        | 186 ++++++++++++--------------
>  2 files changed, 83 insertions(+), 104 deletions(-)
> 
> -- 
> 2.25.1
>