sparc64 now selects HAVE_ARCH_SECCOMP_FILTER, so teach seccomp_bpf how to read and write its registers: the syscall number lives in %g1 and the return value in %o0. The NT_PRSTATUS regset appends the register window read back from the tracee's stack and has no exported layout, so use the sparc-specific PTRACE_GETREGS64/PTRACE_SETREGS64 requests instead, which transfer the uapi struct pt_regs directly.
Errors are signaled by the carry bit in tstate with a positive errno value in %o0, so provide a SYSCALL_RET_SET that maintains both, and mark the arch SYSCALL_RET_SET_ON_PTRACE_EXIT since a return value poked at entry would be overwritten by the syscall skip path, as on powerpc. Passes 95 of 95 on an UltraSPARC T4-1 (16 skipped for missing optional features such as uprobes). Link: https://github.com/sparclinux/issues/issues/11 Signed-off-by: Stian Halseth <[email protected]> --- v2: use PTRACE_GETREGS64/PTRACE_SETREGS64 and the uapi struct pt_regs instead of a locally defined NT_PRSTATUS regset layout, as suggested by Kees Cook. Note the historical %g0 omission in that layout, which shifts the u_regs indices by one. tools/testing/selftests/seccomp/seccomp_bpf.c | 36 +++++++++++++++++++ 1 file changed, 36 insertions(+) diff --git a/tools/testing/selftests/seccomp/seccomp_bpf.c b/tools/testing/selftests/seccomp/seccomp_bpf.c index 0622bc2acad4..3711060c22a7 100644 --- a/tools/testing/selftests/seccomp/seccomp_bpf.c +++ b/tools/testing/selftests/seccomp/seccomp_bpf.c @@ -1872,6 +1872,34 @@ TEST_F(TRACE_poke, getpid_runs_normally) # define ARCH_REGS struct user_regs_struct # define SYSCALL_NUM(_regs) (_regs).orig_d0 # define SYSCALL_RET(_regs) (_regs).d0 +#elif defined(__sparc__) && defined(__arch64__) +# include <asm/ptrace.h> +/* + * PTRACE_GETREGS64/PTRACE_SETREGS64 transfer the uapi struct pt_regs, + * but in the historical layout that omits %g0: the blob starts at %g1, + * so every u_regs index is one lower than the register number suggests. + */ +# define ARCH_REGS struct pt_regs +# define SYSCALL_NUM(_regs) (_regs).u_regs[0] /* %g1 */ +# define SYSCALL_RET(_regs) (_regs).u_regs[7] /* %o0 */ +/* + * A syscall error is signaled by the carry bit in tstate, with the + * errno held in %o0 as a positive value; the carry can only be + * written reliably once the syscall has been skipped or has run. + */ +# define SPARC64_TSTATE_CARRY 0x0000001100000000UL /* xcc.c | icc.c */ +# define SYSCALL_RET_SET(_regs, _val) \ + do { \ + typeof(_val) _result = (_val); \ + if (_result < 0) { \ + SYSCALL_RET(_regs) = -_result; \ + (_regs).tstate |= SPARC64_TSTATE_CARRY; \ + } else { \ + SYSCALL_RET(_regs) = _result; \ + (_regs).tstate &= ~SPARC64_TSTATE_CARRY; \ + } \ + } while (0) +# define SYSCALL_RET_SET_ON_PTRACE_EXIT #else # error "Do not know how to find your architecture's registers and syscalls" #endif @@ -1939,6 +1967,14 @@ const bool ptrace_entry_set_syscall_ret = #if defined(__x86_64__) || defined(__i386__) || defined(__mips__) || defined(__mc68000__) # define ARCH_GETREGS(_regs) ptrace(PTRACE_GETREGS, tracee, 0, &(_regs)) # define ARCH_SETREGS(_regs) ptrace(PTRACE_SETREGS, tracee, 0, &(_regs)) +#elif defined(__sparc__) && defined(__arch64__) +/* + * The NT_PRSTATUS regset appends the register window, which struct + * pt_regs does not carry; the sparc-specific requests transfer + * struct pt_regs directly (and take the buffer in addr). + */ +# define ARCH_GETREGS(_regs) ptrace(PTRACE_GETREGS64, tracee, &(_regs), 0) +# define ARCH_SETREGS(_regs) ptrace(PTRACE_SETREGS64, tracee, &(_regs), 0) #else # define ARCH_GETREGS(_regs) ({ \ struct iovec __v; \ -- 2.43.0
