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authorEdward Tomasz Napierala <trasz@FreeBSD.org>2021-07-25 06:22:47 +0000
committerEdward Tomasz Napierala <trasz@FreeBSD.org>2021-07-25 06:22:57 +0000
commitccc510b46340da563e21549a1a0cb99915d8d623 (patch)
treefb129f9aa62557fb2b5347c3edfa91dd913bec7c
parent0c47338023d44ff130cf69465bd1b2e75ff0bb39 (diff)
downloadsrc-ccc510b46340.tar.gz
src-ccc510b46340.zip
linux: implement signal delivery on arm64
Note that this still uses FreeBSD-style sigframe; this will be addressed later. Reviewed By: dchagin Sponsored By: EPSRC Differential Revision: https://reviews.freebsd.org/D31258
-rw-r--r--sys/arm64/linux/linux.h10
-rw-r--r--sys/arm64/linux/linux_locore.asm4
-rw-r--r--sys/arm64/linux/linux_sysvec.c98
3 files changed, 106 insertions, 6 deletions
diff --git a/sys/arm64/linux/linux.h b/sys/arm64/linux/linux.h
index ab3bab8264f4..7ea169b962b4 100644
--- a/sys/arm64/linux/linux.h
+++ b/sys/arm64/linux/linux.h
@@ -243,6 +243,16 @@ typedef struct l_siginfo {
#define lsi_band _sifields._sigpoll._band
#define lsi_fd _sifields._sigpoll._fd
+/*
+ * This structure is different from the one used by Linux,
+ * but it doesn't matter - it's not user-accessible. We need
+ * it instead of the native one because of l_siginfo.
+ */
+struct l_sigframe {
+ struct l_siginfo sf_si;
+ ucontext_t sf_uc;
+};
+
union l_semun {
l_int val;
l_uintptr_t buf;
diff --git a/sys/arm64/linux/linux_locore.asm b/sys/arm64/linux/linux_locore.asm
index 24a48d74f7b5..0311c2e7e7e9 100644
--- a/sys/arm64/linux/linux_locore.asm
+++ b/sys/arm64/linux/linux_locore.asm
@@ -44,7 +44,9 @@ linux_platform:
.text
+ nop /* This is what Linux calls a "Mysterious NOP". */
ENTRY(__kernel_rt_sigreturn)
- brk #0 /* LINUXTODO: implement __kernel_rt_sigreturn */
+ mov x8, #LINUX_SYS_linux_rt_sigreturn
+ svc #0
ret
END(__kernel_rt_sigreturn)
diff --git a/sys/arm64/linux/linux_sysvec.c b/sys/arm64/linux/linux_sysvec.c
index 72621b4bbfbd..3625155111f2 100644
--- a/sys/arm64/linux/linux_sysvec.c
+++ b/sys/arm64/linux/linux_sysvec.c
@@ -37,12 +37,14 @@ __FBSDID("$FreeBSD$");
#include <sys/imgact.h>
#include <sys/imgact_elf.h>
#include <sys/kernel.h>
+#include <sys/ktr.h>
#include <sys/lock.h>
#include <sys/module.h>
#include <sys/mutex.h>
#include <sys/proc.h>
#include <sys/stddef.h>
#include <sys/signalvar.h>
+#include <sys/syscallsubr.h>
#include <sys/sysctl.h>
#include <sys/sysent.h>
@@ -61,6 +63,7 @@ __FBSDID("$FreeBSD$");
#include <compat/linux/linux_ioctl.h>
#include <compat/linux/linux_mib.h>
#include <compat/linux/linux_misc.h>
+#include <compat/linux/linux_signal.h>
#include <compat/linux/linux_util.h>
#include <compat/linux/linux_vdso.h>
@@ -407,18 +410,103 @@ linux_exec_setregs(struct thread *td, struct image_params *imgp,
int
linux_rt_sigreturn(struct thread *td, struct linux_rt_sigreturn_args *args)
{
+ struct l_sigframe frame;
+ struct trapframe *tf;
+ int error;
+
+ tf = td->td_frame;
+
+ if (copyin((void *)tf->tf_sp, &frame, sizeof(frame)))
+ return (EFAULT);
- /* LINUXTODO: implement */
- LIN_SDT_PROBE0(sysvec, linux_rt_sigreturn, todo);
- return (EDOOFUS);
+ error = set_mcontext(td, &frame.sf_uc.uc_mcontext);
+ if (error != 0)
+ return (error);
+
+ /* Restore signal mask. */
+ kern_sigprocmask(td, SIG_SETMASK, &frame.sf_uc.uc_sigmask, NULL, 0);
+
+ return (EJUSTRETURN);
}
static void
linux_rt_sendsig(sig_t catcher, ksiginfo_t *ksi, sigset_t *mask)
{
+ struct thread *td;
+ struct proc *p;
+ struct trapframe *tf;
+ struct l_sigframe *fp, frame;
+ struct sigacts *psp;
+ int onstack, sig;
+ uint32_t spsr;
+
+ td = curthread;
+ p = td->td_proc;
+ PROC_LOCK_ASSERT(p, MA_OWNED);
+
+ sig = ksi->ksi_signo;
+ psp = p->p_sigacts;
+ mtx_assert(&psp->ps_mtx, MA_OWNED);
+
+ tf = td->td_frame;
+ onstack = sigonstack(tf->tf_sp);
+
+ CTR4(KTR_SIG, "sendsig: td=%p (%s) catcher=%p sig=%d", td, p->p_comm,
+ catcher, sig);
+
+ /* Allocate and validate space for the signal handler context. */
+ if ((td->td_pflags & TDP_ALTSTACK) != 0 && !onstack &&
+ SIGISMEMBER(psp->ps_sigonstack, sig)) {
+ fp = (struct l_sigframe *)((uintptr_t)td->td_sigstk.ss_sp +
+ td->td_sigstk.ss_size);
+#if defined(COMPAT_43)
+ td->td_sigstk.ss_flags |= SS_ONSTACK;
+#endif
+ } else {
+ fp = (struct l_sigframe *)td->td_frame->tf_sp;
+ }
+
+ /* Make room, keeping the stack aligned */
+ fp--;
+ fp = (struct l_sigframe *)STACKALIGN(fp);
+
+ /* Fill in the frame to copy out */
+ bzero(&frame, sizeof(frame));
+ get_mcontext(td, &frame.sf_uc.uc_mcontext, 0);
+ spsr = frame.sf_uc.uc_mcontext.mc_gpregs.gp_spsr;
+
+ /* Translate the signal. */
+ sig = bsd_to_linux_signal(sig);
+
+ siginfo_to_lsiginfo(&ksi->ksi_info, &frame.sf_si, sig);
+ frame.sf_uc.uc_sigmask = *mask;
+ frame.sf_uc.uc_stack = td->td_sigstk;
+ frame.sf_uc.uc_stack.ss_flags = (td->td_pflags & TDP_ALTSTACK) != 0 ?
+ (onstack ? SS_ONSTACK : 0) : SS_DISABLE;
+ mtx_unlock(&psp->ps_mtx);
+ PROC_UNLOCK(td->td_proc);
+
+ /* Copy the sigframe out to the user's stack. */
+ if (copyout(&frame, fp, sizeof(*fp)) != 0) {
+ /* Process has trashed its stack. Kill it. */
+ CTR2(KTR_SIG, "sendsig: sigexit td=%p fp=%p", td, fp);
+ PROC_LOCK(p);
+ sigexit(td, SIGILL);
+ }
+
+ tf->tf_x[0]= sig;
+ tf->tf_x[1] = (register_t)&fp->sf_si;
+ tf->tf_x[2] = (register_t)&fp->sf_uc;
+
+ tf->tf_elr = (register_t)catcher;
+ tf->tf_sp = (register_t)fp;
+ tf->tf_lr = (register_t)__kernel_rt_sigreturn;
+
+ CTR3(KTR_SIG, "sendsig: return td=%p pc=%#x sp=%#x", td, tf->tf_elr,
+ tf->tf_sp);
- /* LINUXTODO: implement */
- LIN_SDT_PROBE0(sysvec, linux_rt_sendsig, todo);
+ PROC_LOCK(p);
+ mtx_lock(&psp->ps_mtx);
}
struct sysentvec elf_linux_sysvec = {