linux/arch
Kai Huang 5d092b6611 x86/tdx: Zero out the missing RSI in TDX_HYPERCALL macro
In the TDX_HYPERCALL asm, after the TDCALL instruction returns from the
untrusted VMM, the registers that the TDX guest shares to the VMM need
to be cleared to avoid speculative execution of VMM-provided values.

RSI is specified in the bitmap of those registers, but it is missing
when zeroing out those registers in the current TDX_HYPERCALL.

It was there when it was originally added in commit 752d13305c
("x86/tdx: Expand __tdx_hypercall() to handle more arguments"), but was
later removed in commit 1e70c68037 ("x86/tdx: Do not corrupt
frame-pointer in __tdx_hypercall()"), which was correct because %rsi is
later restored in the "pop %rsi".  However a later commit 7a3a401874
("x86/tdx: Drop flags from __tdx_hypercall()") removed that "pop %rsi"
but forgot to add the "xor %rsi, %rsi" back.

Fix by adding it back.

Fixes: 7a3a401874 ("x86/tdx: Drop flags from __tdx_hypercall()")
Signed-off-by: Kai Huang <kai.huang@intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
Reviewed-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/all/e7d1157074a0b45d34564d5f17f3e0ffee8115e9.1692096753.git.kai.huang%40intel.com
2023-09-11 16:31:52 -07:00
..
alpha Kbuild updates for v6.6 2023-09-05 11:01:47 -07:00
arc ARC updates for v6.6 2023-09-04 15:38:24 -07:00
arm ARM: 2023-09-07 13:52:20 -07:00
arm64 RISC-V Patches for the 6.6 Merge Window, Part 2 (try 2) 2023-09-09 14:25:11 -07:00
csky arch/csky 2nd patches for 6.6 2023-09-01 08:02:45 -07:00
hexagon Add x86 shadow stack support 2023-08-31 12:20:12 -07:00
ia64 Kbuild updates for v6.6 2023-09-05 11:01:47 -07:00
loongarch LoongArch changes for v6.6 2023-09-08 12:16:52 -07:00
m68k ata changes for 6.6 2023-09-05 12:37:28 -07:00
microblaze Microblaze patches for 6.6-rc1 2023-09-05 10:15:22 -07:00
mips ARM: 2023-09-07 13:52:20 -07:00
nios2 Add x86 shadow stack support 2023-08-31 12:20:12 -07:00
openrisc OpenRISC updates for 6.6 2023-09-05 10:09:31 -07:00
parisc ata changes for 6.6 2023-09-05 12:37:28 -07:00
powerpc ata changes for 6.6 2023-09-05 12:37:28 -07:00
riscv RISC-V Patches for the 6.6 Merge Window, Part 2 (try 2) 2023-09-09 14:25:11 -07:00
s390 Including fixes from netfilter and bpf. 2023-09-07 18:33:07 -07:00
sh sh updates for v6.6 2023-09-09 14:46:57 -07:00
sparc ata changes for 6.6 2023-09-05 12:37:28 -07:00
um This pull request contains the following changes for UML: 2023-09-04 11:32:21 -07:00
x86 x86/tdx: Zero out the missing RSI in TDX_HYPERCALL macro 2023-09-11 16:31:52 -07:00
xtensa Xtensa updates for v6.6 2023-09-07 10:30:17 -07:00
.gitignore
Kconfig Add x86 shadow stack support 2023-08-31 12:20:12 -07:00