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authorRichard Henderson <richard.henderson@linaro.org>2018-07-18 13:06:48 -0700
committerLaurent Vivier <laurent@vivier.eu>2018-07-22 21:33:45 +0200
commitfa97e38eed3bbdbc322d94092ca49450e724fff1 (patch)
tree3bce29b6e2fdb36090534f8cd9f1848fef58f4db
parent33143c446eb88de28ea3088b279feda8f693e398 (diff)
linux-user/ppc: Implement swapcontext syscall
This allows the tests generated by debian-powerpc-user-cross to function properly, especially tests/test-coroutine. Technically this syscall is available to both ppc32 and ppc64, but only ppc32 glibc actually uses it. Thus the ppc64 path is untested. Signed-off-by: Richard Henderson <richard.henderson@linaro.org> Tested-by: Alex Bennée <alex.bennee@linaro.org> Reviewed-by: Alex Bennée <alex.bennee@linaro.org> Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org> Reviewed-by: Laurent Vivier <laurent@vivier.eu> Message-Id: <20180718200648.22529-1-richard.henderson@linaro.org>
-rw-r--r--linux-user/ppc/signal.c56
-rw-r--r--linux-user/qemu.h2
-rw-r--r--linux-user/syscall.c6
3 files changed, 64 insertions, 0 deletions
diff --git a/linux-user/ppc/signal.c b/linux-user/ppc/signal.c
index ef4c518f11..2ae120a2bc 100644
--- a/linux-user/ppc/signal.c
+++ b/linux-user/ppc/signal.c
@@ -675,3 +675,59 @@ sigsegv:
force_sig(TARGET_SIGSEGV);
return -TARGET_QEMU_ESIGRETURN;
}
+
+/* This syscall implements {get,set,swap}context for userland. */
+abi_long do_swapcontext(CPUArchState *env, abi_ulong uold_ctx,
+ abi_ulong unew_ctx, abi_long ctx_size)
+{
+ struct target_ucontext *uctx;
+ struct target_mcontext *mctx;
+
+ /* For ppc32, ctx_size is "reserved for future use".
+ * For ppc64, we do not yet support the VSX extension.
+ */
+ if (ctx_size < sizeof(struct target_ucontext)) {
+ return -TARGET_EINVAL;
+ }
+
+ if (uold_ctx) {
+ TaskState *ts = (TaskState *)thread_cpu->opaque;
+
+ if (!lock_user_struct(VERIFY_WRITE, uctx, uold_ctx, 1)) {
+ return -TARGET_EFAULT;
+ }
+
+#ifdef TARGET_PPC64
+ mctx = &uctx->tuc_sigcontext.mcontext;
+#else
+ /* ??? The kernel aligns the pointer down here into padding, but
+ * in setup_rt_frame we don't. Be self-compatible for now.
+ */
+ mctx = &uctx->tuc_mcontext;
+ __put_user(h2g(mctx), &uctx->tuc_regs);
+#endif
+
+ save_user_regs(env, mctx);
+ host_to_target_sigset(&uctx->tuc_sigmask, &ts->signal_mask);
+
+ unlock_user_struct(uctx, uold_ctx, 1);
+ }
+
+ if (unew_ctx) {
+ int err;
+
+ if (!lock_user_struct(VERIFY_READ, uctx, unew_ctx, 1)) {
+ return -TARGET_EFAULT;
+ }
+ err = do_setcontext(uctx, env, 0);
+ unlock_user_struct(uctx, unew_ctx, 1);
+
+ if (err) {
+ /* We cannot return to a partially updated context. */
+ force_sig(TARGET_SIGSEGV);
+ }
+ return -TARGET_QEMU_ESIGRETURN;
+ }
+
+ return 0;
+}
diff --git a/linux-user/qemu.h b/linux-user/qemu.h
index 7b16a1cdea..b4959e41c6 100644
--- a/linux-user/qemu.h
+++ b/linux-user/qemu.h
@@ -396,6 +396,8 @@ long do_sigreturn(CPUArchState *env);
long do_rt_sigreturn(CPUArchState *env);
abi_long do_sigaltstack(abi_ulong uss_addr, abi_ulong uoss_addr, abi_ulong sp);
int do_sigprocmask(int how, const sigset_t *set, sigset_t *oldset);
+abi_long do_swapcontext(CPUArchState *env, abi_ulong uold_ctx,
+ abi_ulong unew_ctx, abi_long ctx_size);
/**
* block_signals: block all signals while handling this guest syscall
*
diff --git a/linux-user/syscall.c b/linux-user/syscall.c
index 3df3bdffb2..dfc851cc35 100644
--- a/linux-user/syscall.c
+++ b/linux-user/syscall.c
@@ -12790,6 +12790,12 @@ abi_long do_syscall(void *cpu_env, int num, abi_long arg1,
ret = get_errno(kcmp(arg1, arg2, arg3, arg4, arg5));
break;
#endif
+#ifdef TARGET_NR_swapcontext
+ case TARGET_NR_swapcontext:
+ /* PowerPC specific. */
+ ret = do_swapcontext(cpu_env, arg1, arg2, arg3);
+ break;
+#endif
default:
unimplemented: