diff options
author | Arthur Heymans <arthur@aheymans.xyz> | 2022-04-07 21:52:59 +0200 |
---|---|---|
committer | Paul Fagerburg <pfagerburg@chromium.org> | 2022-06-02 15:58:19 +0000 |
commit | 346db92f8c6e42529af6dbcf34caf9c3fb1a5a12 (patch) | |
tree | 3485ae5fe776483c8f4e862388d51a32ffd4cc24 | |
parent | 3b9f71518390f5cdd71ecaf3414cf997fabf5198 (diff) |
cpu/x86/smm_module_loader: Drop superfluous checks
Checking if the stack encroaches on the entry points is done in other
parts of the code.
Change-Id: I275d5dda9c69cc89608450ae27dd5dbd581e3595
Signed-off-by: Arthur Heymans <arthur@aheymans.xyz>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/63480
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
-rw-r--r-- | src/cpu/x86/smm/smm_module_loader.c | 52 |
1 files changed, 5 insertions, 47 deletions
diff --git a/src/cpu/x86/smm/smm_module_loader.c b/src/cpu/x86/smm/smm_module_loader.c index 1c32ecd5be..50e8358cdb 100644 --- a/src/cpu/x86/smm/smm_module_loader.c +++ b/src/cpu/x86/smm/smm_module_loader.c @@ -169,42 +169,15 @@ u32 smm_get_cpu_smbase(unsigned int cpu_num) * important to enter protected mode before the jump because the "jump to * address" might be larger than the 20bit address supported by real mode. * SMI entry right now is in real mode. - * input: smbase - this is the smbase of the first cpu not the smbase - * where tseg starts (aka smram_start). All CPUs code segment - * and stack will be below this point except for the common - * SMI handler which is one segment above * input: num_cpus - number of cpus that need relocation including * the first CPU (though its code is already loaded) - * input: top of stack (stacks work downward by default in Intel HW) - * output: return -1, if runtime smi code could not be installed. In - * this case SMM will not work and any SMI's generated will - * cause a CPU shutdown or general protection fault because - * the appropriate smi handling code was not installed */ -static int smm_place_entry_code(uintptr_t smbase, unsigned int num_cpus, - uintptr_t stack_top, const struct smm_loader_params *params) +static void smm_place_entry_code(const unsigned int num_cpus) { unsigned int i; unsigned int size; - /* - * Ensure there was enough space and the last CPUs smbase - * did not encroach upon the stack. Stack top is smram start - * + size of stack. - */ - if (cpus[num_cpus].active) { - if (cpus[num_cpus - 1].smbase + SMM_ENTRY_OFFSET < stack_top) { - printk(BIOS_ERR, "%s: stack encroachment\n", __func__); - printk(BIOS_ERR, "%s: smbase %lx, stack_top %lx\n", - __func__, cpus[num_cpus].smbase, stack_top); - return 0; - } - } - - printk(BIOS_INFO, "%s: smbase %lx, stack_top %lx\n", - __func__, cpus[num_cpus-1].smbase, stack_top); - /* start at 1, the first CPU stub code is already there */ size = cpus[0].code_end - cpus[0].code_start; for (i = 1; i < num_cpus; i++) { @@ -215,7 +188,6 @@ static int smm_place_entry_code(uintptr_t smbase, unsigned int num_cpus, printk(BIOS_DEBUG, "%s: copying from %lx to %lx 0x%x bytes\n", __func__, cpus[0].code_start, cpus[i].code_start, size); } - return 1; } static uintptr_t stack_top; @@ -245,21 +217,10 @@ int smm_setup_stack(const uintptr_t perm_smbase, const size_t perm_smram_size, * staggered by the per CPU SMM save state size extending down from * SMM_ENTRY_OFFSET. */ -static int smm_stub_place_staggered_entry_points(char *base, - const struct smm_loader_params *params, const struct rmodule *smm_stub) +static void smm_stub_place_staggered_entry_points(const struct smm_loader_params *params) { - size_t stub_entry_offset; - int rc = 1; - stub_entry_offset = rmodule_entry_offset(smm_stub); - /* Each CPU now has its own stub code, which enters protected mode, - * sets up the stack, and then jumps to common SMI handler - */ - if (params->num_concurrent_save_states > 1 || stub_entry_offset != 0) { - rc = smm_place_entry_code((uintptr_t)base, - params->num_concurrent_save_states, - stack_top, params); - } - return rc; + if (params->num_concurrent_save_states > 1) + smm_place_entry_code(params->num_concurrent_save_states); } /* @@ -328,10 +289,7 @@ static int smm_module_setup_stub(const uintptr_t smbase, const size_t smm_size, stub_params->start32_offset); printk(BIOS_DEBUG, "%s: runtime.smm_size = 0x%zx\n", __func__, smm_size); - if (!smm_stub_place_staggered_entry_points((void *)smbase, params, &smm_stub)) { - printk(BIOS_ERR, "%s: staggered entry points failed\n", __func__); - return -1; - } + smm_stub_place_staggered_entry_points(params); printk(BIOS_DEBUG, "SMM Module: stub loaded at %lx. Will call %p\n", smm_stub_loc, params->handler); |