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| author | Will Deacon <[email protected]> | 2020-07-03 08:41:24 +0000 |
|---|---|---|
| committer | Will Deacon <[email protected]> | 2020-07-16 10:41:58 +0000 |
| commit | 139dbe5d8ed383cbd1ada56c78dbbbd35bf6a9d3 (patch) | |
| tree | 7ab72588884da81954b1f9f882795c80dd556cd6 /drivers/perf/arm-ccn.c | |
| parent | arm64: ptrace: Add a comment describing our syscall entry/exit trap ABI (diff) | |
| download | kernel-139dbe5d8ed383cbd1ada56c78dbbbd35bf6a9d3.tar.gz kernel-139dbe5d8ed383cbd1ada56c78dbbbd35bf6a9d3.zip | |
arm64: syscall: Expand the comment about ptrace and syscall(-1)
If a task executes syscall(-1), we intercept this early and force x0 to
be -ENOSYS so that we don't need to distinguish this scenario from one
where the scno is -1 because a tracer wants to skip the system call
using ptrace. With the return value set, the return path is the same as
the skip case.
Although there is a one-line comment noting this in el0_svc_common(), it
misses out most of the detail. Expand the comment to describe a bit more
about what is going on.
Cc: Mark Rutland <[email protected]>
Cc: Keno Fischer <[email protected]>
Cc: Luis Machado <[email protected]>
Signed-off-by: Will Deacon <[email protected]>
Diffstat (limited to 'drivers/perf/arm-ccn.c')
0 files changed, 0 insertions, 0 deletions