[PATCH v7 09/10] powerpc/signal64: Rewrite rt_sigreturn() to minimise uaccess switches
From: Christopher M. Riedl <hidden>
Date: 2021-02-27 01:13:53
Subsystem:
linux for powerpc (32-bit and 64-bit), the rest · Maintainers:
Madhavan Srinivasan, Linus Torvalds
From: Daniel Axtens <redacted> Add uaccess blocks and use the 'unsafe' versions of functions doing user access where possible to reduce the number of times uaccess has to be opened/closed. Signed-off-by: Daniel Axtens <redacted> Co-developed-by: Christopher M. Riedl <redacted> Signed-off-by: Christopher M. Riedl <redacted> --- arch/powerpc/kernel/signal_64.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-)
diff --git a/arch/powerpc/kernel/signal_64.c b/arch/powerpc/kernel/signal_64.c
index 788854734b9a..00c907022707 100644
--- a/arch/powerpc/kernel/signal_64.c
+++ b/arch/powerpc/kernel/signal_64.c@@ -822,11 +822,11 @@ SYSCALL_DEFINE0(rt_sigreturn) */ current->thread.regs->msr &= ~MSR_TS_MASK; if (!user_read_access_begin(&uc->uc_mcontext, sizeof(uc->uc_mcontext))) - return -EFAULT; - if (__unsafe_restore_sigcontext(current, NULL, 1, &uc->uc_mcontext)) { - user_read_access_end(); goto badframe; - } + + unsafe_restore_sigcontext(current, NULL, 1, &uc->uc_mcontext, + badframe_block); + user_read_access_end(); }
@@ -836,6 +836,8 @@ SYSCALL_DEFINE0(rt_sigreturn) set_thread_flag(TIF_RESTOREALL); return 0; +badframe_block: + user_read_access_end(); badframe: signal_fault(current, regs, "rt_sigreturn", uc);
--
2.26.1