Merge remote-tracking branch 'remotes/vivier/tags/linux-user-for-6.2-pull-request' into staging

Pull request linux-user 20211004

Move signal trampolines to new page

# gpg: Signature made Mon 04 Oct 2021 12:43:53 AM PDT
# gpg:                using RSA key CD2F75DDC8E3A4DC2E4F5173F30C38BD3F2FBE3C
# gpg:                issuer "laurent@vivier.eu"
# gpg: Good signature from "Laurent Vivier <lvivier@redhat.com>" [full]
# gpg:                 aka "Laurent Vivier <laurent@vivier.eu>" [full]
# gpg:                 aka "Laurent Vivier (Red Hat) <lvivier@redhat.com>" [full]

* remotes/vivier/tags/linux-user-for-6.2-pull-request: (26 commits)
  tests/tcg/multiarch: Re-enable signals test for most guests
  linux-user: Remove default for TARGET_ARCH_HAS_SIGTRAMP_PAGE
  linux-user/xtensa: Implement setup_sigtramp
  linux-user/sparc: Implement setup_sigtramp
  linux-user/sh4: Implement setup_sigtramp
  linux-user/s390x: Implement setup_sigtramp
  linux-user/riscv: Implement setup_sigtramp
  linux-user/ppc: Implement setup_sigtramp
  linux-user/ppc: Simplify encode_trampoline
  linux-user/openrisc: Implement setup_sigtramp
  linux-user/nios2: Document non-use of setup_sigtramp
  linux-user/mips: Implement setup_sigtramp
  linux-user/mips: Tidy install_sigtramp
  linux-user/microblaze: Implement setup_sigtramp
  linux-user/m68k: Implement setup_sigtramp
  linux-user/x86_64: Raise SIGSEGV if SA_RESTORER not set
  linux-user/i386: Implement setup_sigtramp
  linux-user/hppa: Document non-use of setup_sigtramp
  linux-user/hexagon: Implement setup_sigtramp
  linux-user/cris: Implement setup_sigtramp
  ...

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

1 files changed, 22 insertions, 18 deletions

diff --git a/linux-user/sh4/signal.c b/linux-user/sh4/signal.c
index d70d744bef..faa869fb19 100644
--- a/linux-user/sh4/signal.c
+++ b/linux-user/sh4/signal.c
@@ -52,7 +52,6 @@ struct target_sigframe
 {
     struct target_sigcontext sc;
     target_ulong extramask[TARGET_NSIG_WORDS-1];
-    uint16_t retcode[3];
 };
 
 
@@ -68,7 +67,6 @@ struct target_rt_sigframe
 {
     struct target_siginfo info;
     struct target_ucontext uc;
-    uint16_t retcode[3];
 };
 
 
@@ -190,15 +188,9 @@ void setup_frame(int sig, struct target_sigaction *ka,
     /* Set up to return from userspace.  If provided, use a stub
        already in userspace.  */
     if (ka->sa_flags & TARGET_SA_RESTORER) {
-        regs->pr = (unsigned long) ka->sa_restorer;
+        regs->pr = ka->sa_restorer;
     } else {
-        /* Generate return code (system call to sigreturn) */
-        abi_ulong retcode_addr = frame_addr +
-                                 offsetof(struct target_sigframe, retcode);
-        __put_user(MOVW(2), &frame->retcode[0]);
-        __put_user(TRAP_NOARG, &frame->retcode[1]);
-        __put_user((TARGET_NR_sigreturn), &frame->retcode[2]);
-        regs->pr = (unsigned long) retcode_addr;
+        regs->pr = default_sigreturn;
     }
 
     /* Set up registers for signal handler */
@@ -248,15 +240,9 @@ void setup_rt_frame(int sig, struct target_sigaction *ka,
     /* Set up to return from userspace.  If provided, use a stub
        already in userspace.  */
     if (ka->sa_flags & TARGET_SA_RESTORER) {
-        regs->pr = (unsigned long) ka->sa_restorer;
+        regs->pr = ka->sa_restorer;
     } else {
-        /* Generate return code (system call to sigreturn) */
-        abi_ulong retcode_addr = frame_addr +
-                                 offsetof(struct target_rt_sigframe, retcode);
-        __put_user(MOVW(2), &frame->retcode[0]);
-        __put_user(TRAP_NOARG, &frame->retcode[1]);
-        __put_user((TARGET_NR_rt_sigreturn), &frame->retcode[2]);
-        regs->pr = (unsigned long) retcode_addr;
+        regs->pr = default_rt_sigreturn;
     }
 
     /* Set up registers for signal handler */
@@ -334,3 +320,21 @@ badframe:
     force_sig(TARGET_SIGSEGV);
     return -TARGET_QEMU_ESIGRETURN;
 }
+
+void setup_sigtramp(abi_ulong sigtramp_page)
+{
+    uint16_t *tramp = lock_user(VERIFY_WRITE, sigtramp_page, 2 * 6, 0);
+    assert(tramp != NULL);
+
+    default_sigreturn = sigtramp_page;
+    __put_user(MOVW(2), &tramp[0]);
+    __put_user(TRAP_NOARG, &tramp[1]);
+    __put_user(TARGET_NR_sigreturn, &tramp[2]);
+
+    default_rt_sigreturn = sigtramp_page + 6;
+    __put_user(MOVW(2), &tramp[3]);
+    __put_user(TRAP_NOARG, &tramp[4]);
+    __put_user(TARGET_NR_rt_sigreturn, &tramp[5]);
+
+    unlock_user(tramp, sigtramp_page, 2 * 6);
+}