Update the comments (the location of trampoline code)

Also, fix typos and copy-and-paste errors.

arch/arm/src/armv6-m/up_signal_dispatch.c

@@ -60,9 +60,9 @@
  *   This kernel-mode stub will then be called transfer control to the user
  *   mode signal handler by calling this function.
  *
- *   Normally the a user-mode signalling handling stub will also execute
+ *   Normally the user-mode signalling handling stub will also execute
  *   before the ultimate signal handler is called.  See
- *   arch/arm/src/armv[6\7]/up_signal_handler.  This function is the
+ *   arch/arm/src/armv6-m/up_signal_handler.S.  This function is the
  *   user-space, signal handler trampoline function.  It is called from
  *   up_signal_dispatch() in user-mode.
  *

arch/arm/src/armv6-m/up_svcall.c

@@ -369,7 +369,7 @@ int up_svcall(int irq, FAR void *context, FAR void *arg)
           DEBUGASSERT(rtcb->xcp.sigreturn == 0);
           rtcb->xcp.sigreturn  = regs[REG_PC];
 
-          /* Set up to return to the user-space pthread start-up function in
+          /* Set up to return to the user-space trampoline function in
            * unprivileged mode.
            */
 

arch/arm/src/armv7-a/arm_signal_dispatch.c

@@ -61,9 +61,9 @@
  *   This kernel-mode stub will then be called transfer control to the user
  *   mode signal handler by calling this function.
  *
- *   Normally the a user-mode signalling handling stub will also execute
+ *   Normally the user-mode signalling handling stub will also execute
  *   before the ultimate signal handler is called.  See
- *   arch/arm/src/armv[6\7]/up_signal_handler.  This function is the
+ *   arch/arm/src/armv7-a/crt0.c.  This function is the
  *   user-space, signal handler trampoline function.  It is called from
  *   up_signal_dispatch() in user-mode.
  *

arch/arm/src/armv7-a/arm_syscall.c

@@ -343,7 +343,7 @@ uint32_t *arm_syscall(uint32_t *regs)
           DEBUGASSERT(rtcb->xcp.sigreturn == 0);
           rtcb->xcp.sigreturn  = regs[REG_PC];
 
-          /* Set up to return to the user-space pthread start-up function in
+          /* Set up to return to the user-space trampoline function in
            * unprivileged mode.
            */
 

arch/arm/src/armv7-m/up_signal_dispatch.c

@@ -60,9 +60,9 @@
  *   This kernel-mode stub will then be called transfer control to the user
  *   mode signal handler by calling this function.
  *
- *   Normally the a user-mode signaling handling stub will also execute
+ *   Normally the user-mode signaling handling stub will also execute
  *   before the ultimate signal handler is called.  See
- *   arch/arm/src/armv[6\7]/up_signal_handler.  This function is the
+ *   arch/arm/src/armv7-m/gnu/up_signal_handler.S.  This function is the
  *   user-space, signal handler trampoline function.  It is called from
  *   up_signal_dispatch() in user-mode.
  *

arch/arm/src/armv7-m/up_svcall.c

@@ -369,7 +369,7 @@ int up_svcall(int irq, FAR void *context, FAR void *arg)
           DEBUGASSERT(rtcb->xcp.sigreturn == 0);
           rtcb->xcp.sigreturn  = regs[REG_PC];
 
-          /* Set up to return to the user-space pthread start-up function in
+          /* Set up to return to the user-space trampoline function in
            * unprivileged mode.
            */
 

arch/arm/src/armv7-r/arm_syscall.c

@@ -341,7 +341,7 @@ uint32_t *arm_syscall(uint32_t *regs)
           DEBUGASSERT(rtcb->xcp.sigreturn == 0);
           rtcb->xcp.sigreturn  = regs[REG_PC];
 
-          /* Set up to return to the user-space pthread start-up function in
+          /* Set up to return to the user-space trampoline function in
            * unprivileged mode.
            */
 

arch/risc-v/src/rv64gc/up_signal_dispatch.c

@@ -45,9 +45,9 @@
  *   This kernel-mode stub will then be called transfer control to the user
  *   mode signal handler by calling this function.
  *
- *   Normally the a user-mode signaling handling stub will also execute
+ *   Normally the user-mode signaling handling stub will also execute
  *   before the ultimate signal handler is called.  See
- *   arch/arm/src/armv[6\7]/up_signal_handler.  This function is the
+ *   arch/risc-v/src/rv64gc/up_signal_handler.S.  This function is the
  *   user-space, signal handler trampoline function.  It is called from
  *   up_signal_dispatch() in user-mode.
  *

arch/risc-v/src/rv64gc/up_swint.c

@@ -349,7 +349,7 @@ int up_swint(int irq, FAR void *context, FAR void *arg)
           DEBUGASSERT(rtcb->xcp.sigreturn == 0);
           rtcb->xcp.sigreturn  = regs[REG_EPC];
 
-          /* Set up to return to the user-space pthread start-up function in
+          /* Set up to return to the user-space trampoline function in
            * unprivileged mode.
            */