Messages in this thread Patch in this message | | | Date | Thu, 13 Dec 2018 20:24:30 +0300 | From | "Dmitry V. Levin" <> | Subject | [PATCH v6 25/27] powerpc/ptrace: replace ptrace_report_syscall() with a tracehook call |
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From: Elvira Khabirova <lineprinter@altlinux.org>
Arch code should use tracehook_*() helpers, as documented in include/linux/tracehook.h, ptrace_report_syscall() is not expected to be used outside that file.
The patch does not look very nice, but at least it is correct and opens the way for PTRACE_GET_SYSCALL_INFO API.
Co-authored-by: Dmitry V. Levin <ldv@altlinux.org> Fixes: 5521eb4bca2d ("powerpc/ptrace: Add support for PTRACE_SYSEMU") Signed-off-by: Elvira Khabirova <lineprinter@altlinux.org> Signed-off-by: Dmitry V. Levin <ldv@altlinux.org> [mpe: Take this as a minimal fix for 4.20, we'll rework it later] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> ---
Notes: v6: this is the fix that was taken into powerpc tree v5: reverted to a simple approach, compile- and run-tested v4: rewritten to call tracehook_report_syscall_entry() once, compile-tested v3: add a descriptive comment v2: explicitly ignore tracehook_report_syscall_entry() return code
arch/powerpc/kernel/ptrace.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/arch/powerpc/kernel/ptrace.c b/arch/powerpc/kernel/ptrace.c index afb819f4ca68..714c3480c52d 100644 --- a/arch/powerpc/kernel/ptrace.c +++ b/arch/powerpc/kernel/ptrace.c @@ -3266,12 +3266,17 @@ long do_syscall_trace_enter(struct pt_regs *regs) user_exit(); if (test_thread_flag(TIF_SYSCALL_EMU)) { - ptrace_report_syscall(regs); /* + * A nonzero return code from tracehook_report_syscall_entry() + * tells us to prevent the syscall execution, but we are not + * going to execute it anyway. + * * Returning -1 will skip the syscall execution. We want to * avoid clobbering any register also, thus, not 'gotoing' * skip label. */ + if (tracehook_report_syscall_entry(regs)) + ; return -1; } -- ldv
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