Resolve writable shadow_fd destination in sendfile#65
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ChuWeiChang wants to merge 1 commit intosysprog21:mainfrom
Open
Resolve writable shadow_fd destination in sendfile#65ChuWeiChang wants to merge 1 commit intosysprog21:mainfrom
ChuWeiChang wants to merge 1 commit intosysprog21:mainfrom
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When intercepting sendfile with out_fd as shadow_fd, forward_sendfile mistakenly treat it as host_fd instead of shadow_sp. Fix this by explicitly querying the out_fd's FD table entry. If shadow_writeback is enabled, extract and write to shadow_sp instead. Change-Id: Ifbe431c557f8d10cb2f4ab221176da336e35e067
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Fixes #64 and also help with test gap 5 in #38
Overview
There is a routing bug in
forward_sendfileinseccomp_dispatch.cwhere destination shadow FDs were bypassing the virtual kernel (shadow_sp) and writing directly to the underlying physical host_fd.What this PR does
fd_table_entrylookup for the destinationout_fdprior to the emulation loop.test/guest/sendfile-test.cSummary by cubic
Fixes sendfile routing when the destination fd has a writeback shadow. Writes now go to the
shadow_spinstead of the host fd, ensuring correct sync and data visibility.out_fdvia the fd table and, whenshadow_writebackis set, write toshadow_spinsideforward_sendfile.sendfile-testto verify data is written through the shadow path and enable it inrun-tests.sh.Written for commit 00006c0. Summary will update on new commits.