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| author | Dmitry Chagin <dchagin@FreeBSD.org> | 2023-05-28 14:06:23 +0000 |
|---|---|---|
| committer | Dmitry Chagin <dchagin@FreeBSD.org> | 2023-05-28 14:06:23 +0000 |
| commit | 185bd9fa3096595350ebe7bcd7e0ddcf17773030 (patch) | |
| tree | 939e10a9ffff16d77d9ef7f09ac83ab7d3781a20 | |
| parent | a463dd810851fdae5efcb8f8205d742ebf221bc8 (diff) | |
| download | src-185bd9fa3096595350ebe7bcd7e0ddcf17773030.tar.gz src-185bd9fa3096595350ebe7bcd7e0ddcf17773030.zip | |
linux(4): Simplify %r10 restoring on amd64
Restore %r10 at system call entry to avoid doing this multiply times.
Differential Revision: https://reviews.freebsd.org/D40154
MFC after: 1 month
| -rw-r--r-- | sys/amd64/linux/linux_machdep.c | 6 | ||||
| -rw-r--r-- | sys/amd64/linux/linux_sysvec.c | 6 |
2 files changed, 3 insertions, 9 deletions
diff --git a/sys/amd64/linux/linux_machdep.c b/sys/amd64/linux/linux_machdep.c index 6ac0ab0cd3d7..155ea918cd0a 100644 --- a/sys/amd64/linux/linux_machdep.c +++ b/sys/amd64/linux/linux_machdep.c @@ -350,12 +350,6 @@ linux_ptrace_getregs_machdep(struct thread *td, pid_t pid, linux_msg(td, "PT_LWPINFO failed with error %d", error); return (error); } - if ((lwpinfo.pl_flags & PL_FLAG_SCE) != 0) { - /* - * Undo the mangling done in exception.S:fast_syscall_common(). - */ - l_regset->r10 = l_regset->rcx; - } if ((lwpinfo.pl_flags & (PL_FLAG_SCE | PL_FLAG_SCX)) != 0) { /* * In Linux, the syscall number - passed to the syscall diff --git a/sys/amd64/linux/linux_sysvec.c b/sys/amd64/linux/linux_sysvec.c index 89d388dc6cf8..422cfbe7c5ba 100644 --- a/sys/amd64/linux/linux_sysvec.c +++ b/sys/amd64/linux/linux_sysvec.c @@ -167,6 +167,9 @@ linux_fetch_syscall_args(struct thread *td) else sa->callp = &p->p_sysent->sv_table[sa->code]; + /* Restore r10 earlier to avoid doing this multiply times. */ + frame->tf_r10 = frame->tf_rcx; + td->td_retval[0] = 0; return (0); } @@ -181,7 +184,6 @@ linux_set_syscall_retval(struct thread *td, int error) switch (error) { case 0: frame->tf_rax = td->td_retval[0]; - frame->tf_r10 = frame->tf_rcx; break; case ERESTART: @@ -192,7 +194,6 @@ linux_set_syscall_retval(struct thread *td, int error) * */ frame->tf_rip -= frame->tf_err; - frame->tf_r10 = frame->tf_rcx; break; case EJUSTRETURN: @@ -200,7 +201,6 @@ linux_set_syscall_retval(struct thread *td, int error) default: frame->tf_rax = bsd_to_linux_errno(error); - frame->tf_r10 = frame->tf_rcx; break; } |