Le 13/08/2021 à 15:18, Peter Maydell a écrit : > Coverity reported that we don't set the _sifields union when queuing > the SIGTRAP for EXCP_DEBUG events on aarch64. This series fixes that > bug and a few others, and cleans up the way we queue fault signals > to be less error-prone. > > The underlying cause of the bug is that when queueing a signal > the code must set the right field in the _sifields union depending > on the si_type that it passes to queue_signal(), and there's nothing > guarding against forgetting to do this. The "fill in a whole struct > and then call queue_signal()" code is also a bit longwinded. In the > real kernel, there is a function force_sig_fault() which does this > for the SI_FAULT signal type. The series provides a QEMU implementation > of this (which goes alongside the existing force_sig() that does this > for SI_KILL signals), and uses it in the arm and aarch64 code. > Because force_sig_fault() takes the address as an argument, it's > not possible for the caller to forget to fill it in. > > Obviously we should also convert the other targets where they are > directly calling queue_signal() (there are other places that forget > to fill in the sifields union fields; I don't know why Coverity > hasn't spotted those). But I thought it better to send this out > for review of the new API and approach before spending time on > converting other targets. (In particular fixing places where > EXCP_DEBUG handling forgets to set the sifields address is a > pain, because in the real kernel different architectures might > either report the PC or else report a zero address here, so it > requires looking into the kernel sources to check which...) > Once all the archs are cleaned up we might be able to make > queue_signal() static so it's local to signal.c. > > PS: there's probably a trivial conflict with my include-file-split > patchseries. > > thanks > -- PMM > > Peter Maydell (7): > linux-user/aarch64: Set siginfo_t addr field for SIGTRAP signals > linux-user/arm: Set siginfo_t addr field for SIGTRAP signals > linux-user/arm: Use force_sig() to deliver fpa11 emulation SIGFPE > linux-user: Zero out target_siginfo_t in force_sig() > linux-user: Provide new force_sig_fault() function > linux-user/arm: Use force_sig_fault() > linux-user/aarch64: Use force_sig_fault() > > linux-user/signal-common.h | 1 + > linux-user/aarch64/cpu_loop.c | 33 +++++------------- > linux-user/arm/cpu_loop.c | 64 +++++++++++------------------------ > linux-user/signal.c | 19 ++++++++++- > 4 files changed, 48 insertions(+), 69 deletions(-) >
Applied to my linux-user-for-6.2 branch. Thanks, Laurent
