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| author | Xin Li <xin3.li@intel.com> | 2023-12-05 11:50:18 +0100 |
|---|---|---|
| committer | Borislav Petkov (AMD) <bp@alien8.de> | 2024-01-31 22:03:04 +0100 |
| commit | 5105e7687ad3dffde77f6e4393b5530e83d672dc (patch) | |
| tree | bc3f17dae2474cf5e4b411b6e249e2c52ceef121 /arch/x86/mm/pgtable_32.c | |
| parent | x86/fred: Let ret_from_fork_asm() jmp to asm_fred_exit_user when FRED is enabled (diff) | |
| download | linux-5105e7687ad3dffde77f6e4393b5530e83d672dc.tar.xz linux-5105e7687ad3dffde77f6e4393b5530e83d672dc.zip | |
x86/fred: Fixup fault on ERETU by jumping to fred_entrypoint_user
If the stack frame contains an invalid user context (e.g. due to invalid SS,
a non-canonical RIP, etc.) the ERETU instruction will trap (#SS or #GP).
From a Linux point of view, this really should be considered a user space
failure, so use the standard fault fixup mechanism to intercept the fault,
fix up the exception frame, and redirect execution to fred_entrypoint_user.
The end result is that it appears just as if the hardware had taken the
exception immediately after completing the transition to user space.
Suggested-by: H. Peter Anvin (Intel) <hpa@zytor.com>
Signed-off-by: Xin Li <xin3.li@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Tested-by: Shan Kang <shan.kang@intel.com>
Link: https://lore.kernel.org/r/20231205105030.8698-30-xin3.li@intel.com
Diffstat (limited to 'arch/x86/mm/pgtable_32.c')
0 files changed, 0 insertions, 0 deletions