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| author |   Johannes Berg <johannes.berg@intel.com> | 2025-02-10 17:09:25 +0100 |
|---|---|---|
| committer | Johannes Berg <johannes.berg@intel.com> | 2025-03-18 11:03:14 +0100 |
| commit | d1d7f01f7cd35e16c6bcef5a0e31988b5c9980f9 (patch) | |
| tree | ac2a7b2c4ccc6a9f1749c48eca519d615d125942 /scripts/basic/git:/ssh:/git@git.zx2c4.com | |
| parent | um: Pass the correct Rust target and options with gcc (diff) | |
| download | wireguard-linux-d1d7f01f7cd35e16c6bcef5a0e31988b5c9980f9.tar.xz wireguard-linux-d1d7f01f7cd35e16c6bcef5a0e31988b5c9980f9.zip | |
um: mark rodata read-only and implement _nofault accesses
Mark read-only data actually read-only (simple mprotect), and
to be able to test it also implement _nofault accesses. This
works by setting up a new "segv_continue" pointer in current,
and then when we hit a segfault we change the signal return
context so that we continue at that address. The code using
this sets it up so that it jumps to a label and then aborts
the access that way, returning -EFAULT.
It's possible to optimize the ___backtrack_faulted() thing by
using asm goto (compiler version dependent) and/or gcc's (not
sure if clang has it) &&label extension, but at least in one
attempt I made the && caused the compiler to not load -EFAULT
into the register in case of jumping to the &&label from the
fault handler. So leave it like this for now.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Co-developed-by: Benjamin Berg <benjamin.berg@intel.com>
Signed-off-by: Benjamin Berg <benjamin.berg@intel.com>
Link: https://patch.msgid.link/20250210160926.420133-2-benjamin@sipsolutions.net
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Diffstat (limited to 'scripts/basic/git:/ssh:/git@git.zx2c4.com')
0 files changed, 0 insertions, 0 deletions