33 lines
1.4 KiB
Diff
33 lines
1.4 KiB
Diff
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commit 7be7af0fda3633cd19e499617834cf4a5f51dd55
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Author: William Cohen <wcohen@redhat.com>
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Date: Tue Jul 23 14:24:14 2019 -0400
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Fix aarch64 to properly access arguments for wrapped syscalls
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Linux 4.18 added wrappers for aarch64 syscalls that pass a pointer to
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a struct pt_regs holding the values for the actual arguments. The
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syscall tapsets initialize CONTEXT->sregs to point at this data
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structure. However, the aarch64 specific register access code was
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using the CONTEXT->kregs and just getting the processor register state
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when the kprobe triggered rather than the expected arguments in the
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data structure being passed into the syscall. The aarch64 specific
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register code now gets the syscall arguments from the correct pt_regs
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structure.
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diff --git a/tapset/arm64/registers.stp b/tapset/arm64/registers.stp
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index b2e5649..8773df2 100644
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--- a/tapset/arm64/registers.stp
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+++ b/tapset/arm64/registers.stp
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@@ -58,7 +58,10 @@ function uarch_bytes:long() {
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function _stp_get_register_by_offset:long (offset:long) %{ /* pure */
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long value;
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struct pt_regs *regs;
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- regs = (CONTEXT->user_mode_p ? CONTEXT->uregs : CONTEXT->kregs);
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+ if (CONTEXT->sregs)
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+ regs = CONTEXT->sregs;
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+ else
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+ regs = (CONTEXT->user_mode_p ? CONTEXT->uregs : CONTEXT->kregs);
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if (!regs) {
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CONTEXT->last_error = "No registers available in this context";
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return;
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