linux_dsm_epyc7002/arch
Will Deacon 59ee987ea4 arm64: ptrace: Add a comment describing our syscall entry/exit trap ABI
Our tracehook logic for syscall entry/exit raises a SIGTRAP back to the
tracer following a ptrace request such as PTRACE_SYSCALL. As part of this
procedure, we clobber the reported value of one of the tracee's general
purpose registers (x7 for native tasks, r12 for compat) to indicate
whether the stop occurred on syscall entry or exit. This is a slightly
unfortunate ABI, as it prevents the tracer from accessing the real
register value and is at odds with other similar stops such as seccomp
traps.

Since we're stuck with this ABI, expand the comment in our tracehook
logic to acknowledge the issue and describe the behaviour in more detail.

Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Luis Machado <luis.machado@linaro.org>
Reported-by: Keno Fischer <keno@juliacomputing.com>
Signed-off-by: Will Deacon <will@kernel.org>
2020-07-16 11:41:41 +01:00
..
alpha Kbuild updates for v5.8 (2nd) 2020-06-13 13:29:16 -07:00
arc treewide: replace '---help---' in Kconfig files with 'help' 2020-06-14 01:57:21 +09:00
arm Kbuild updates for v5.8 (2nd) 2020-06-13 13:29:16 -07:00
arm64 arm64: ptrace: Add a comment describing our syscall entry/exit trap ABI 2020-07-16 11:41:41 +01:00
c6x This time around we have 4 lines of diff in the core framework, removing a 2020-06-10 11:42:19 -07:00
csky mmap locking API: use coccinelle to convert mmap_sem rwsem call sites 2020-06-09 09:39:14 -07:00
h8300 This time around we have 4 lines of diff in the core framework, removing a 2020-06-10 11:42:19 -07:00
hexagon treewide: replace '---help---' in Kconfig files with 'help' 2020-06-14 01:57:21 +09:00
ia64 treewide: replace '---help---' in Kconfig files with 'help' 2020-06-14 01:57:21 +09:00
m68k Kbuild updates for v5.8 (2nd) 2020-06-13 13:29:16 -07:00
microblaze mmap locking API: convert mmap_sem comments 2020-06-09 09:39:14 -07:00
mips Kbuild updates for v5.8 (2nd) 2020-06-13 13:29:16 -07:00
nds32 mmap locking API: convert mmap_sem comments 2020-06-09 09:39:14 -07:00
nios2 nios2 update for v5.8-rc1 2020-06-12 11:55:11 -07:00
openrisc OpenRISC updates for 5.8 2020-06-13 10:54:09 -07:00
parisc treewide: replace '---help---' in Kconfig files with 'help' 2020-06-14 01:57:21 +09:00
powerpc Kbuild updates for v5.8 (2nd) 2020-06-13 13:29:16 -07:00
riscv RISC-V Patches for the 5.8 Merge Window, Part 2 2020-06-11 12:55:20 -07:00
s390 Kbuild updates for v5.8 (2nd) 2020-06-13 13:29:16 -07:00
sh treewide: replace '---help---' in Kconfig files with 'help' 2020-06-14 01:57:21 +09:00
sparc treewide: replace '---help---' in Kconfig files with 'help' 2020-06-14 01:57:21 +09:00
um treewide: replace '---help---' in Kconfig files with 'help' 2020-06-14 01:57:21 +09:00
unicore32 This time around we have 4 lines of diff in the core framework, removing a 2020-06-10 11:42:19 -07:00
x86 Kbuild updates for v5.8 (2nd) 2020-06-13 13:29:16 -07:00
xtensa mmap locking API: convert mmap_sem API comments 2020-06-09 09:39:14 -07:00
.gitignore .gitignore: add SPDX License Identifier 2020-03-25 11:50:48 +01:00
Kconfig treewide: replace '---help---' in Kconfig files with 'help' 2020-06-14 01:57:21 +09:00