compel: Store extended registers set in the thread context

Extended registers set for task is restored with rt_sigreturn() through
prepared sigframe. For threads it's currently lost.
Preserve it inside thread context to restore on thread curing.

Signed-off-by: Dmitry Safonov <dima@arista.com>

6 files changed, 40 insertions, 36 deletions

diff --git a/compel/arch/aarch64/src/lib/infect.c b/compel/arch/aarch64/src/lib/infect.c
index 4b5939022..39428cd8d 100644
--- a/compel/arch/aarch64/src/lib/infect.c
+++ b/compel/arch/aarch64/src/lib/infect.c
@@ -60,11 +60,12 @@ int sigreturn_prep_fpu_frame_plain(struct rt_sigframe *sigframe,
 	return 0;
 }
 
-int get_task_regs(pid_t pid, user_regs_struct_t *regs, save_regs_t save,
+int compel_get_task_regs(pid_t pid, user_regs_struct_t *regs,
+		  user_fpregs_struct_t *ext_regs, save_regs_t save,
 		  void *arg, __maybe_unused unsigned long flags)
 {
+	user_fpregs_struct_t tmp, *fpsimd = ext_regs ? ext_regs : &tmp;
 	struct iovec iov;
-	user_fpregs_struct_t fpsimd;
 	int ret;
 
 	pr_info("Dumping GP/FPU registers for %d\n", pid);
@@ -76,14 +77,14 @@ int get_task_regs(pid_t pid, user_regs_struct_t *regs, save_regs_t save,
 		goto err;
 	}
 
-	iov.iov_base = &fpsimd;
-	iov.iov_len = sizeof(fpsimd);
+	iov.iov_base = fpsimd;
+	iov.iov_len = sizeof(*fpsimd);
 	if ((ret = ptrace(PTRACE_GETREGSET, pid, NT_PRFPREG, &iov))) {
 		pr_perror("Failed to obtain FPU registers for %d", pid);
 		goto err;
 	}
 
-	ret = save(arg, regs, &fpsimd);
+	ret = save(arg, regs, fpsimd);
 err:
 	return ret;
 }
diff --git a/compel/arch/arm/src/lib/infect.c b/compel/arch/arm/src/lib/infect.c
index 75b985b74..dd5aa9784 100644
--- a/compel/arch/arm/src/lib/infect.c
+++ b/compel/arch/arm/src/lib/infect.c
@@ -69,15 +69,16 @@ int sigreturn_prep_fpu_frame_plain(struct rt_sigframe *sigframe,
 }
 
 #define PTRACE_GETVFPREGS 27
-int get_task_regs(pid_t pid, user_regs_struct_t *regs, save_regs_t save,
+int compel_get_task_regs(pid_t pid, user_regs_struct_t *regs,
+		  user_fpregs_struct_t *ext_regs, save_regs_t save,
 		  void *arg, __maybe_unused unsigned long flags)
 {
-	user_fpregs_struct_t vfp;
+	user_fpregs_struct_t tmp, *vfp = ext_regs ? ext_regs : &tmp;
 	int ret = -1;
 
 	pr_info("Dumping GP/FPU registers for %d\n", pid);
 
-	if (ptrace(PTRACE_GETVFPREGS, pid, NULL, &vfp)) {
+	if (ptrace(PTRACE_GETVFPREGS, pid, NULL, vfp)) {
 		pr_perror("Can't obtain FPU registers for %d", pid);
 		goto err;
 	}
@@ -99,7 +100,7 @@ int get_task_regs(pid_t pid, user_regs_struct_t *regs, save_regs_t save,
 		}
 	}
 
-	ret = save(arg, regs, &vfp);
+	ret = save(arg, regs, vfp);
 err:
 	return ret;
 }
diff --git a/compel/arch/mips/src/lib/infect.c b/compel/arch/mips/src/lib/infect.c
index 35e947cc0..6a53b3c3b 100755
--- a/compel/arch/mips/src/lib/infect.c
+++ b/compel/arch/mips/src/lib/infect.c
@@ -122,13 +122,14 @@ int sigreturn_prep_fpu_frame_plain(struct rt_sigframe *sigframe,
     return 0;
 }
 
-int get_task_regs(pid_t pid, user_regs_struct_t *regs, save_regs_t save,
+int compel_get_task_regs(pid_t pid, user_regs_struct_t *regs,
+		  user_fpregs_struct_t *ext_regs, save_regs_t save,
 		  void *arg, __maybe_unused unsigned long flags)
 {
-	user_fpregs_struct_t xsave = {  }, *xs = NULL;
+	user_fpregs_struct_t xsave = {  }, *xs = ext_regs ? ext_regs : &xsave;
 	int ret = -1;
 
-	if (ptrace(PTRACE_GETFPREGS, pid, NULL, &xsave)) {
+	if (ptrace(PTRACE_GETFPREGS, pid, NULL, xs)) {
 	    pr_perror("Can't obtain FPU registers for %d", pid);
 	    return ret;
 	}
@@ -151,7 +152,6 @@ int get_task_regs(pid_t pid, user_regs_struct_t *regs, save_regs_t save,
 	    regs->regs[0] = 0;
 	}
 
-	xs = &xsave;
 	ret = save(arg, regs, xs);
 	return ret;
 }
diff --git a/compel/arch/ppc64/src/lib/infect.c b/compel/arch/ppc64/src/lib/infect.c
index b2c725f62..339e01209 100644
--- a/compel/arch/ppc64/src/lib/infect.c
+++ b/compel/arch/ppc64/src/lib/infect.c
@@ -372,17 +372,18 @@ static int __get_task_regs(pid_t pid, user_regs_struct_t *regs,
 	return 0;
 }
 
-int get_task_regs(pid_t pid, user_regs_struct_t *regs, save_regs_t save,
+int compel_get_task_regs(pid_t pid, user_regs_struct_t *regs,
+		  user_fpregs_struct_t *ext_regs, save_regs_t save,
 		  void *arg, __maybe_unused unsigned long flags)
 {
-	user_fpregs_struct_t fpregs;
+	user_fpregs_struct_t tmp, *fpregs = ext_regs ? ext_regs : &tmp;
 	int ret;
 
-	ret = __get_task_regs(pid, regs, &fpregs);
+	ret = __get_task_regs(pid, regs, fpregs);
 	if (ret)
 		return ret;
 
-	return save(arg, regs, &fpregs);
+	return save(arg, regs, fpregs);
 }
 
 int compel_syscall(struct parasite_ctl *ctl, int nr, long *ret,
diff --git a/compel/arch/s390/src/lib/infect.c b/compel/arch/s390/src/lib/infect.c
index 5a4675449..5b3c0d62e 100644
--- a/compel/arch/s390/src/lib/infect.c
+++ b/compel/arch/s390/src/lib/infect.c
@@ -310,31 +310,32 @@ static int s390_disable_ri_bit(pid_t pid, user_regs_struct_t *regs)
 /*
  * Prepare task registers for restart
  */
-int get_task_regs(pid_t pid, user_regs_struct_t *regs, save_regs_t save,
+int compel_get_task_regs(pid_t pid, user_regs_struct_t *regs,
+		  user_fpregs_struct_t *ext_regs, save_regs_t save,
 		  void *arg, __maybe_unused unsigned long flags)
 {
-	user_fpregs_struct_t fpregs;
+	user_fpregs_struct_t tmp, *fpregs = ext_regs ? ext_regs : &tmp;
 	struct iovec iov;
 	int rewind;
 
-	print_user_regs_struct("get_task_regs", pid, regs);
+	print_user_regs_struct("compel_get_task_regs", pid, regs);
 
-	memset(&fpregs, 0, sizeof(fpregs));
-	iov.iov_base = &fpregs.prfpreg;
-	iov.iov_len = sizeof(fpregs.prfpreg);
+	memset(fpregs, 0, sizeof(*fpregs));
+	iov.iov_base = &fpregs->prfpreg;
+	iov.iov_len = sizeof(fpregs->prfpreg);
 	if (ptrace(PTRACE_GETREGSET, pid, NT_PRFPREG, &iov) < 0) {
 		pr_perror("Couldn't get floating-point registers");
 		return -1;
 	}
-	if (get_vx_regs(pid, &fpregs)) {
+	if (get_vx_regs(pid, fpregs)) {
 		pr_perror("Couldn't get vector registers");
 		return -1;
 	}
-	if (get_gs_cb(pid, &fpregs)) {
+	if (get_gs_cb(pid, fpregs)) {
 		pr_perror("Couldn't get guarded-storage");
 		return -1;
 	}
-	if (get_ri_cb(pid, &fpregs)) {
+	if (get_ri_cb(pid, fpregs)) {
 		pr_perror("Couldn't get runtime-instrumentation");
 		return -1;
 	}
@@ -343,10 +344,10 @@ int get_task_regs(pid_t pid, user_regs_struct_t *regs, save_regs_t save,
 	 * before we execute parasite code. Otherwise parasite operations
 	 * would be recorded.
 	 */
-	if (fpregs.flags & USER_RI_ON)
+	if (fpregs->flags & USER_RI_ON)
 		s390_disable_ri_bit(pid, regs);
 
-	print_user_fpregs_struct("get_task_regs", pid, &fpregs);
+	print_user_fpregs_struct("compel_get_task_regs", pid, fpregs);
 	/* Check for system call restarting. */
 	if (regs->system_call) {
 		rewind = regs->system_call >> 16;
@@ -366,7 +367,7 @@ int get_task_regs(pid_t pid, user_regs_struct_t *regs, save_regs_t save,
 		}
 	}
 	/* Call save_task_regs() */
-	return save(arg, regs, &fpregs);
+	return save(arg, regs, fpregs);
 }
 
 /*
diff --git a/compel/arch/x86/src/lib/infect.c b/compel/arch/x86/src/lib/infect.c
index 401001942..9d81083f7 100644
--- a/compel/arch/x86/src/lib/infect.c
+++ b/compel/arch/x86/src/lib/infect.c
@@ -334,10 +334,11 @@ static int corrupt_extregs(pid_t pid)
 	return 0;
 }
 
-int get_task_regs(pid_t pid, user_regs_struct_t *regs, save_regs_t save,
+int compel_get_task_regs(pid_t pid, user_regs_struct_t *regs,
+		  user_fpregs_struct_t *ext_regs, save_regs_t save,
 		  void *arg, unsigned long flags)
 {
-	user_fpregs_struct_t xsave = { }, *xs = NULL;
+	user_fpregs_struct_t xsave = { }, *xs = ext_regs ? ext_regs : &xsave;
 	int ret = -1;
 
 	pr_info("Dumping general registers for %d in %s mode\n", pid,
@@ -371,18 +372,18 @@ int get_task_regs(pid_t pid, user_regs_struct_t *regs, save_regs_t save,
 	pr_info("Dumping GP/FPU registers for %d\n", pid);
 
 	if (!compel_cpu_has_feature(X86_FEATURE_OSXSAVE)) {
-		ret = get_task_fpregs(pid, &xsave);
+		ret = get_task_fpregs(pid, xs);
 	} else if (unlikely(flags & INFECT_X86_PTRACE_MXCSR_BUG)) {
 		/*
 		 * get_task_fpregs() will fill FP state,
 		 * get_task_xsave() will overwrite rightly sse/mmx/etc
 		 */
 		pr_warn("Skylake xsave fpu bug workaround used\n");
-		ret = get_task_fpregs(pid, &xsave);
+		ret = get_task_fpregs(pid, xs);
 		if (!ret)
-			ret = get_task_xsave(pid, &xsave);
+			ret = get_task_xsave(pid, xs);
 	} else {
-		ret = get_task_xsave(pid, &xsave);
+		ret = get_task_xsave(pid, xs);
 	}
 
 	if (!ret && unlikely(flags & INFECT_CORRUPT_EXTREGS))
@@ -391,7 +392,6 @@ int get_task_regs(pid_t pid, user_regs_struct_t *regs, save_regs_t save,
 	if (ret)
 		goto err;
 
-	xs = &xsave;
 out:
 	ret = save(arg, regs, xs);
 err: