From: Ard Biesheuvel <ardb@xxxxxxxxxx>
The SEV code that may run early is now built with -fPIC and so there is
no longer a need for explicit RIP-relative references in inline asm,
given that is what the compiler will emit as well.
Signed-off-by: Ard Biesheuvel <ardb@xxxxxxxxxx>
---
arch/x86/mm/mem_encrypt_identity.c | 37 +++-----------------
1 file changed, 5 insertions(+), 32 deletions(-)
diff --git a/arch/x86/mm/mem_encrypt_identity.c b/arch/x86/mm/mem_encrypt_identity.c
index 20b23da4a26d..2d857e3a560a 100644
--- a/arch/x86/mm/mem_encrypt_identity.c
+++ b/arch/x86/mm/mem_encrypt_identity.c
@@ -86,10 +86,6 @@ struct sme_populate_pgd_data {
*/
static char sme_workarea[2 * PMD_SIZE] __section(".init.scratch");
-static char sme_cmdline_arg[] __initdata = "mem_encrypt";
-static char sme_cmdline_on[] __initdata = "on";
-static char sme_cmdline_off[] __initdata = "off";
-
static void __pitext sme_clear_pgd(struct sme_populate_pgd_data *ppd)
{
unsigned long pgd_start, pgd_end, pgd_size;
@@ -333,14 +329,6 @@ void __pitext sme_encrypt_kernel(struct boot_params *bp)
}
#endif
- /*
- * We're running identity mapped, so we must obtain the address to the
- * SME encryption workarea using rip-relative addressing.
- */
- asm ("lea sme_workarea(%%rip), %0"
- : "=r" (workarea_start)
- : "p" (sme_workarea));
-
/*
* Calculate required number of workarea bytes needed:
* executable encryption area size:
@@ -350,7 +338,7 @@ void __pitext sme_encrypt_kernel(struct boot_params *bp)
* pagetable structures for the encryption of the kernel
* pagetable structures for workarea (in case not currently mapped)
*/
- execute_start = workarea_start;
+ execute_start = workarea_start = (unsigned long)sme_workarea;
execute_end = execute_start + (PAGE_SIZE * 2) + PMD_SIZE;
execute_len = execute_end - execute_start;
@@ -517,9 +505,9 @@ static int __pitext __strncmp(const char *cs, const char *ct, size_t count)
void __pitext sme_enable(struct boot_params *bp)
{
- const char *cmdline_ptr, *cmdline_arg, *cmdline_on, *cmdline_off;
unsigned int eax, ebx, ecx, edx;
unsigned long feature_mask;
+ const char *cmdline_ptr;
bool active_by_default;
unsigned long me_mask;
char buffer[16];
@@ -590,21 +578,6 @@ void __pitext sme_enable(struct boot_params *bp)
goto out;
}
- /*
- * Fixups have not been applied to phys_base yet and we're running
- * identity mapped, so we must obtain the address to the SME command
- * line argument data using rip-relative addressing.
- */
- asm ("lea sme_cmdline_arg(%%rip), %0"
- : "=r" (cmdline_arg)
- : "p" (sme_cmdline_arg));
- asm ("lea sme_cmdline_on(%%rip), %0"
- : "=r" (cmdline_on)
- : "p" (sme_cmdline_on));
- asm ("lea sme_cmdline_off(%%rip), %0"
- : "=r" (cmdline_off)
- : "p" (sme_cmdline_off));
-
if (IS_ENABLED(CONFIG_AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT))
active_by_default = true;
else
@@ -613,12 +586,12 @@ void __pitext sme_enable(struct boot_params *bp)
cmdline_ptr = (const char *)((u64)bp->hdr.cmd_line_ptr |
((u64)bp->ext_cmd_line_ptr << 32));
- if (cmdline_find_option(cmdline_ptr, cmdline_arg, buffer, sizeof(buffer)) < 0)
+ if (cmdline_find_option(cmdline_ptr, "mem_encrypt", buffer, sizeof(buffer)) < 0)
return;
- if (!__strncmp(buffer, cmdline_on, sizeof(buffer)))
+ if (!__strncmp(buffer, "on", sizeof(buffer)))
sme_me_mask = me_mask;
- else if (!__strncmp(buffer, cmdline_off, sizeof(buffer)))
+ else if (!__strncmp(buffer, "off", sizeof(buffer)))
sme_me_mask = 0;
else
sme_me_mask = active_by_default ? me_mask : 0;
--
2.43.0.429.g432eaa2c6b-goog
