Messages in this thread | | | Date | Wed, 25 Jan 2023 15:53:47 +0700 | From | Ammar Faizi <> | Subject | Re: [RFC PATCH v5 1/2] selftests/x86: sysret_rip: Handle syscall in a FRED system |
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On Wed, Jan 25, 2023 at 12:39:26AM -0800, H. Peter Anvin wrote: > > + ret = check_regs_result(ctx->uc_mcontext.gregs[REG_R11], > > + ctx->uc_mcontext.gregs[REG_RCX], > > + ctx->uc_mcontext.gregs[REG_RBX]); > > + > > + assert(ret != REGS_ERROR); > > + > > This instance, too, needs to be checked against regs_ok_result. It would > make most sense to move that handling, and the assert() into > check_regs_result() or into a separate function around it.
OK. Sounds better.
> > /* Set IP and CX to match so that SYSRET can happen. */ > > ctx->uc_mcontext.gregs[REG_RIP] = rip; > > ctx->uc_mcontext.gregs[REG_RCX] = rip; > > It would be interesting to have the syscall handler try both with and > without this (so it would end up doing both IRET and SYSCALL on legacy.) > Perhaps SIGUSR1 versus SIGUSR2...
We will have a new separate patch for that.
-- Ammar Faizi
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