On 16/09/2016 18:38, Konrad Rzeszutek Wilk wrote:
The patch piggybacks on: livepatch: Initial ARM64 support, which
brings up all of the neccessary livepatch infrastructure pieces in.
This patch adds three major pieces:
1) ELF relocations. ARM32 uses SHT_REL instead of SHT_RELA which
means the adddendum had to be extracted from within the
instruction. Which required parsing BL/BLX, B/BL<cond>,
MOVT, and MOVW instructions.
The code was written from scratch using the ARM ELF manual
(and the ARM Architecture Reference Manual)
2) Inserting an trampoline. We use the B (branch to address)
which uses an offset that is based on the PC value: PC + imm32.
Because we insert the branch at the start of the old function
we have to account for the instruction already being fetched
and subtract -8 from the delta (new_addr - old_addr). See
ARM DDI 0406C.c, see A2.3 (pg 45) and A8.8.18 pg (pg 334,335)
3) Allows the test-cases to be built under ARM 32.
The "livepatch: tests: Make them compile under ARM64"
put in the right infrastructure for it and we piggyback on it.
Acked-by: Jan Beulich <jbeul...@suse.com> [for non-ARM parts]
Signed-off-by: Konrad Rzeszutek Wilk <konrad.w...@oracle.com>
Acked-by: Julien Grall <julien.gr...@arm.com>
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