Re: [RFC PATCH] arm: Don't trap conditional UDF instructions

2020-05-13 Thread Robin Murphy
On 2020-05-13 7:56 pm, Fredrik Strupe wrote: On 13.05.2020 20:12, Russell King - ARM Linux admin wrote: On Wed, May 13, 2020 at 05:41:58PM +0200, Fredrik Strupe wrote: Hi, This is more of a question than a patch, but I hope the attached patch makes the issue a bit clearer. The arm port of

Re: [RFC PATCH] arm: Don't trap conditional UDF instructions

2020-05-13 Thread Fredrik Strupe
On 13.05.2020 20:12, Russell King - ARM Linux admin wrote: > On Wed, May 13, 2020 at 05:41:58PM +0200, Fredrik Strupe wrote: >> Hi, >> >> This is more of a question than a patch, but I hope the attached patch makes >> the issue a bit clearer. >> >> The arm port of Linux supports hooking/trapping

Re: [RFC PATCH] arm: Don't trap conditional UDF instructions

2020-05-13 Thread Russell King - ARM Linux admin
On Wed, May 13, 2020 at 05:41:58PM +0200, Fredrik Strupe wrote: > Hi, > > This is more of a question than a patch, but I hope the attached patch makes > the issue a bit clearer. > > The arm port of Linux supports hooking/trapping of undefined instructions. > Some > parts of the code use this to

[RFC PATCH] arm: Don't trap conditional UDF instructions

2020-05-13 Thread Fredrik Strupe
Hi, This is more of a question than a patch, but I hope the attached patch makes the issue a bit clearer. The arm port of Linux supports hooking/trapping of undefined instructions. Some parts of the code use this to trap UDF instructions with certain immediates in order to use them for other