Messages in this thread | | | Date | Fri, 2 Sep 2022 18:59:37 +0100 | From | Al Viro <> | Subject | Re: [PATCH] riscv: fix a nasty sigreturn bug... |
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On Fri, Sep 02, 2022 at 11:22:45AM +0200, Andrew Jones wrote:
> So, for riscv, where in do_signal and handle_signal syscall restarting > is avoided when regs->cause != EXC_SYSCALL and it's common to set cause > to -1 to avoid it, then it makes sense to set regs->cause != EXEC_SYSCALL > in rt_sigreturn or in restore_sigcontext, which rt_sigreturn calls, as > well. > > So the only question I have is whether or not the cause assignment > is better in restore_sigcontext() like other architectures? At least, > since rt_sigreturn is the only caller of restore_sigcontext, it can't > break anything putting it there atm...
The only reason for doing that in restore_sigcontext() is that for old architectures there'd been separate sigreturn(2) and rt_sigreturn(2). Doing that in the helper shared by both avoided duplication; since there's no such thing on riscv...
Matter of taste, really - I have a slight preference for doing that closer to the syscall surface, but it's no more than that.
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