linux/arch/x86
Thomas Gleixner 4facb95b7a x86/entry: Unbreak 32bit fast syscall
Andy reported that the syscall treacing for 32bit fast syscall fails:

# ./tools/testing/selftests/x86/ptrace_syscall_32
...
[RUN] SYSEMU
[FAIL] Initial args are wrong (nr=224, args=10 11 12 13 14 4289172732)
...
[RUN] SYSCALL
[FAIL] Initial args are wrong (nr=29, args=0 0 0 0 0 4289172732)
 
The eason is that the conversion to generic entry code moved the retrieval
of the sixth argument (EBP) after the point where the syscall entry work
runs, i.e. ptrace, seccomp, audit...

Unbreak it by providing a split up version of syscall_enter_from_user_mode().

- syscall_enter_from_user_mode_prepare() establishes state and enables
  interrupts

- syscall_enter_from_user_mode_work() runs the entry work

Replace the call to syscall_enter_from_user_mode() in the 32bit fast
syscall C-entry with the split functions and stick the EBP retrieval
between them.

Fixes: 27d6b4d14f ("x86/entry: Use generic syscall entry function")
Reported-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/87k0xdjbtt.fsf@nanos.tec.linutronix.de
2020-09-04 15:50:14 +02:00
..
boot treewide: Use fallthrough pseudo-keyword 2020-08-23 17:36:59 -05:00
configs x86/defconfigs: Refresh defconfig files 2020-07-25 12:02:14 +02:00
crypto crypto: x86/curve25519 - Remove unused carry variables 2020-07-31 18:25:29 +10:00
entry x86/entry: Unbreak 32bit fast syscall 2020-09-04 15:50:14 +02:00
events treewide: Use fallthrough pseudo-keyword 2020-08-23 17:36:59 -05:00
hyperv
ia32 mm: remove unneeded includes of <asm/pgalloc.h> 2020-08-07 11:33:26 -07:00
include x86/entry: Fix AC assertion 2020-09-04 15:09:29 +02:00
kernel x86/debug: Allow a single level of #DB recursion 2020-09-04 15:09:29 +02:00
kvm treewide: Use fallthrough pseudo-keyword 2020-08-23 17:36:59 -05:00
lib x86/cmdline: Disable jump tables for cmdline.c 2020-09-03 10:59:16 +02:00
math-emu treewide: Use fallthrough pseudo-keyword 2020-08-23 17:36:59 -05:00
mm x86, fakenuma: Fix invalid starting node ID 2020-09-04 08:56:13 +02:00
net
oprofile
pci xen: branch for v5.9-rc2 2020-08-21 12:28:33 -07:00
platform efi/x86: Move 32-bit code into efi_32.c 2020-08-20 11:18:36 +02:00
power Kbuild updates for v5.9 2020-08-09 14:10:26 -07:00
purgatory Misc fixes and small updates all around the place: 2020-08-15 10:38:03 -07:00
ras
realmode
tools
um kbuild: remove cc-option test of -fno-stack-protector 2020-07-07 11:13:10 +09:00
video
xen xen: branch for v5.9-rc1b 2020-08-14 13:34:37 -07:00
.gitignore
Kbuild
Kconfig A set of posix CPU timer changes which allows to defer the heavy work of 2020-08-14 14:17:51 -07:00
Kconfig.assembler
Kconfig.cpu
Kconfig.debug locking/lockdep: Fix TRACE_IRQFLAGS vs. NMIs 2020-07-27 15:13:29 +02:00
Makefile Kbuild updates for v5.9 2020-08-09 14:10:26 -07:00
Makefile_32.cpu
Makefile.um