diff options
| author | Patrick Rudolph <patrick.rudolph@9elements.com> | 2021-11-30 18:34:32 +0100 |
|---|---|---|
| committer | Patrick Georgi <patrick@coreboot.org> | 2021-12-06 12:37:48 +0000 |
| commit | 5b334b88a635e46d47ce3f3b703d2470d6e8514c (patch) | |
| tree | e57abd4d22b9ccaa7c771de1ad18845991521b9f /src/security/intel/txt | |
| parent | c7f0bca9c23ac8d96ffc5ec0fcaddf9190d7dbff (diff) | |
x86_64 assembly: Don't touch %gs
With CPU_INFO_V2 enabled %gs holds the pointer to the cpu_info struct,
so don't clobber it. Backup and restore %gs where possible.
Fixes a crash in MPinit seen after calling FSP-S.
Change-Id: If9fc999b34530de5d8b6ad27b9af25fc552e9420
Signed-off-by: Patrick Rudolph <patrick.rudolph@9elements.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/59764
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Arthur Heymans <arthur@aheymans.xyz>
Diffstat (limited to 'src/security/intel/txt')
| -rw-r--r-- | src/security/intel/txt/getsec_enteraccs.S | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/src/security/intel/txt/getsec_enteraccs.S b/src/security/intel/txt/getsec_enteraccs.S index 09f9f389e6..cbb24b6511 100644 --- a/src/security/intel/txt/getsec_enteraccs.S +++ b/src/security/intel/txt/getsec_enteraccs.S @@ -227,6 +227,10 @@ cond_clear_var_mtrrs: movd %esp, %xmm0 movd %ebp, %xmm1 + /* Backup %gs used by CPU_INFO_V2 */ + movl %gs, %eax + movd %eax, %xmm2 + /* * Get function arguments. * It's important to pass the exact ACM size as it's used by getsec to verify @@ -261,6 +265,8 @@ cond_clear_var_mtrrs: movl %eax, %es movl %eax, %ss movl %eax, %fs + /* Restore %gs used by CPU_INFO_V2 */ + movd %xmm2, %eax movl %eax, %gs /* Disable cache */ |