From cde9070d9970eef1f7ec2360586c802a16230ad8 Mon Sep 17 00:00:00 2001 From: hc <hc@nodka.com> Date: Fri, 10 May 2024 07:43:50 +0000 Subject: [PATCH] rtl88x2CE_WiFi_linux driver --- kernel/Documentation/arm64/tagged-pointers.rst | 25 +++++++++++++++++++------ 1 files changed, 19 insertions(+), 6 deletions(-) diff --git a/kernel/Documentation/arm64/tagged-pointers.rst b/kernel/Documentation/arm64/tagged-pointers.rst index eab4323..19d284b 100644 --- a/kernel/Documentation/arm64/tagged-pointers.rst +++ b/kernel/Documentation/arm64/tagged-pointers.rst @@ -53,12 +53,25 @@ Preserving tags --------------- -Non-zero tags are not preserved when delivering signals. This means that -signal handlers in applications making use of tags cannot rely on the -tag information for user virtual addresses being maintained for fields -inside siginfo_t. One exception to this rule is for signals raised in -response to watchpoint debug exceptions, where the tag information will -be preserved. +When delivering signals, non-zero tags are not preserved in +siginfo.si_addr unless the flag SA_EXPOSE_TAGBITS was set in +sigaction.sa_flags when the signal handler was installed. This means +that signal handlers in applications making use of tags cannot rely +on the tag information for user virtual addresses being maintained +in these fields unless the flag was set. + +Due to architecture limitations, bits 63:60 of the fault address +are not preserved in response to synchronous tag check faults +(SEGV_MTESERR) even if SA_EXPOSE_TAGBITS was set. Applications should +treat the values of these bits as undefined in order to accommodate +future architecture revisions which may preserve the bits. + +For signals raised in response to watchpoint debug exceptions, the +tag information will be preserved regardless of the SA_EXPOSE_TAGBITS +flag setting. + +Non-zero tags are never preserved in sigcontext.fault_address +regardless of the SA_EXPOSE_TAGBITS flag setting. The architecture prevents the use of a tagged PC, so the upper byte will be set to a sign-extension of bit 55 on exception return. -- Gitblit v1.6.2