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cpu/x86/mtrr: fail early if solution exceeds available MTRRs

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If an MTRR solution exceeds the number of available MTRRs
don't attempt to commit the result. It will just GP fault
with the MSR write to an invalid MSR address.

Change-Id: I5c4912d5244526544c299c3953bca1bf884b34d5
Signed-off-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-on: https://review.coreboot.org/20163
Reviewed-by: Youness Alaoui <snifikino@gmail.com>
Reviewed-by: Furquan Shaikh <furquan@google.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Philippe Mathieu-Daudé <philippe.mathieu.daude@gmail.com>
This commit is contained in:
Aaron Durbin 2017-06-12 12:48:38 -05:00
parent e1058c7c99
commit d9762f70ac
1 changed files with 15 additions and 3 deletions
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18
src/cpu/x86/mtrr/mtrr.c
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@ -751,10 +751,16 @@ static void prepare_var_mtrrs(struct memranges *addr_space, int def_type,
sol->num_used = var_state.mtrr_index;
}
static void commit_var_mtrrs(const struct var_mtrr_solution *sol)
static int commit_var_mtrrs(const struct var_mtrr_solution *sol)
{
int i;
if (sol->num_used > total_mtrrs) {
printk(BIOS_WARNING, "Not enough MTRRs: %d vs %d\n",
sol->num_used, total_mtrrs);
return -1;
}
/* Write out the variable MTRRs. */
disable_cache();
for (i = 0; i < sol->num_used; i++) {
@ -767,6 +773,7 @@ static void commit_var_mtrrs(const struct var_mtrr_solution *sol)
enable_var_mtrr(sol->mtrr_default_type);
enable_cache();
return 0;
}
void x86_setup_var_mtrrs(unsigned int address_bits, unsigned int above4gb)
@ -872,10 +879,15 @@ void mtrr_use_temp_range(uintptr_t begin, size_t size, int type)
calc_var_mtrrs(&addr_space, above4gb, address_bits);
prepare_var_mtrrs(&addr_space, sol.mtrr_default_type,
above4gb, address_bits, &sol);
commit_var_mtrrs(&sol);
if (commit_var_mtrrs(&sol) < 0)
printk(BIOS_WARNING, "Unable to insert temporary MTRR range: 0x%016llx - 0x%016llx size 0x%08llx type %d\n",
(long long)begin, (long long)begin + size,
(long long)size, type);
else
put_back_original_solution = true;
memranges_teardown(&addr_space);
put_back_original_solution = true;
}
static void remove_temp_solution(void *unused)