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| author |   Guo Ren <ren_guo@c-sky.com> | 2019-04-02 16:02:33 +0800 |
|---|---|---|
| committer |   Palmer Dabbelt <palmer@sifive.com> | 2019-04-25 11:07:36 -0700 |
| commit | 7a64f3f1cffdc3db2e9de885bc49a6a9851aac62 (patch) | |
| tree | 64466273a0db2e7553ff94b30d47f1545ac24bb9 /arch/riscv | |
| parent | Linux 5.1-rc6 (diff) | |
| download | linux-dev-7a64f3f1cffdc3db2e9de885bc49a6a9851aac62.tar.xz linux-dev-7a64f3f1cffdc3db2e9de885bc49a6a9851aac62.zip | |
riscv/signal: Fixup additional syscall restarting
The function of do_notify_resume called by entry.S could be entered
in loop when SIGPENDING was setted again before sret. So we must add
prevent code to make syscall restart (regs->sepc -= 0x4) or it may
re-execute unexpected instructions.
Just like in_syscall & forget_syscall used by arm.
Signed-off-by: Guo Ren <ren_guo@c-sky.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
Diffstat (limited to 'arch/riscv')
| -rw-r--r-- | arch/riscv/kernel/signal.c | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/arch/riscv/kernel/signal.c b/arch/riscv/kernel/signal.c index 837e1646091a..804d6ee4f3c5 100644 --- a/arch/riscv/kernel/signal.c +++ b/arch/riscv/kernel/signal.c @@ -234,6 +234,9 @@ static void handle_signal(struct ksignal *ksig, struct pt_regs *regs) /* Are we from a system call? */ if (regs->scause == EXC_SYSCALL) { + /* Avoid additional syscall restarting via ret_from_exception */ + regs->scause = -1UL; + /* If so, check system call restarting.. */ switch (regs->a0) { case -ERESTART_RESTARTBLOCK: @@ -272,6 +275,9 @@ static void do_signal(struct pt_regs *regs) /* Did we come from a system call? */ if (regs->scause == EXC_SYSCALL) { + /* Avoid additional syscall restarting via ret_from_exception */ + regs->scause = -1UL; + /* Restart the system call - no handlers present */ switch (regs->a0) { case -ERESTARTNOHAND: |