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, 26 insertions, 14 deletions

diff --git a/linux-user/sparc/signal.c b/linux-user/sparc/signal.c
index 3bc023d281..23e1e761de 100644
--- a/linux-user/sparc/signal.c
+++ b/linux-user/sparc/signal.c
@@ -242,6 +242,12 @@ static void restore_fpu(struct target_siginfo_fpu *fpu, CPUSPARCState *env)
 }
 
 #ifdef TARGET_ARCH_HAS_SETUP_FRAME
+static void install_sigtramp(uint32_t *tramp, int syscall)
+{
+    __put_user(0x82102000u + syscall, &tramp[0]); /* mov syscall, %g1 */
+    __put_user(0x91d02010u, &tramp[1]);           /* t 0x10 */
+}
+
 void setup_frame(int sig, struct target_sigaction *ka,
                  target_sigset_t *set, CPUSPARCState *env)
 {
@@ -291,13 +297,9 @@ void setup_frame(int sig, struct target_sigaction *ka,
     if (ka->ka_restorer) {
         env->regwptr[WREG_O7] = ka->ka_restorer;
     } else {
-        env->regwptr[WREG_O7] = sf_addr +
-                offsetof(struct target_signal_frame, insns) - 2 * 4;
-
-        /* mov __NR_sigreturn, %g1 */
-        __put_user(0x821020d8u, &sf->insns[0]);
-        /* t 0x10 */
-        __put_user(0x91d02010u, &sf->insns[1]);
+        /* Not used, but retain for ABI compatibility. */
+        install_sigtramp(sf->insns, TARGET_NR_sigreturn);
+        env->regwptr[WREG_O7] = default_sigreturn;
     }
     unlock_user(sf, sf_addr, sf_size);
 }
@@ -358,13 +360,9 @@ void setup_rt_frame(int sig, struct target_sigaction *ka,
     if (ka->ka_restorer) {
         env->regwptr[WREG_O7] = ka->ka_restorer;
     } else {
-        env->regwptr[WREG_O7] =
-            sf_addr + offsetof(struct target_rt_signal_frame, insns) - 2 * 4;
-
-        /* mov __NR_rt_sigreturn, %g1 */
-        __put_user(0x82102065u, &sf->insns[0]);
-        /* t 0x10 */
-        __put_user(0x91d02010u, &sf->insns[1]);
+        /* Not used, but retain for ABI compatibility. */
+        install_sigtramp(sf->insns, TARGET_NR_rt_sigreturn);
+        env->regwptr[WREG_O7] = default_rt_sigreturn;
     }
 #else
     env->regwptr[WREG_O7] = ka->ka_restorer;
@@ -775,4 +773,18 @@ do_sigsegv:
     unlock_user_struct(ucp, ucp_addr, 1);
     force_sig(TARGET_SIGSEGV);
 }
+#else
+void setup_sigtramp(abi_ulong sigtramp_page)
+{
+    uint32_t *tramp = lock_user(VERIFY_WRITE, sigtramp_page, 2 * 8, 0);
+    assert(tramp != NULL);
+
+    default_sigreturn = sigtramp_page;
+    install_sigtramp(tramp, TARGET_NR_sigreturn);
+
+    default_rt_sigreturn = sigtramp_page + 8;
+    install_sigtramp(tramp + 2, TARGET_NR_rt_sigreturn);
+
+    unlock_user(tramp, sigtramp_page, 2 * 8);
+}
 #endif