From d9762f70acc1cc2db5b3905756f5f5a995b9a21a Mon Sep 17 00:00:00 2001 From: Aaron Durbin Date: Mon, 12 Jun 2017 12:48:38 -0500 Subject: cpu/x86/mtrr: fail early if solution exceeds available MTRRs MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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 Reviewed-on: https://review.coreboot.org/20163 Reviewed-by: Youness Alaoui Reviewed-by: Furquan Shaikh Tested-by: build bot (Jenkins) Reviewed-by: Philippe Mathieu-Daudé --- src/cpu/x86/mtrr/mtrr.c | 18 +++++++++++++++--- 1 file changed, 15 insertions(+), 3 deletions(-) (limited to 'src/cpu/x86/mtrr') diff --git a/src/cpu/x86/mtrr/mtrr.c b/src/cpu/x86/mtrr/mtrr.c index e7c69be482..609d1e76db 100644 --- a/src/cpu/x86/mtrr/mtrr.c +++ b/src/cpu/x86/mtrr/mtrr.c @@ -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) -- cgit v1.2.3