From 0f92433b8f9f76608528101e7a81cd3bfd00e236 Mon Sep 17 00:00:00 2001 From: Daniel Axtens Date: Fri, 26 Feb 2021 19:12:58 -0600 Subject: [PATCH] powerpc/signal64: Rewrite rt_sigreturn() to minimise uaccess switches 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. Co-developed-by: Christopher M. Riedl Signed-off-by: Daniel Axtens Signed-off-by: Christopher M. Riedl Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20210227011259.11992-10-cmr@codefail.de --- 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 057507138320..e7d612e82363 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); -- 2.11.0