diff options
author | Luigi Semenzato <semenzato@chromium.org> | 2011-07-21 17:03:20 -0700 |
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committer | Luigi Semenzato <semenzato@chromium.org> | 2011-07-22 09:27:54 -0700 |
commit | 1c9577b213a3a7515e91034ee131d3b459559880 (patch) | |
tree | bb8585d289858c19d9a8788a58d618a793c404e6 | |
parent | cba0e83d91b33c3ef9c71fc7dc24c1370e7f3e9a (diff) | |
download | vboot-1c9577b213a3a7515e91034ee131d3b459559880.tar.gz |
Implement different strategy for soft-reset workaround on Kaen prototypes.
BUG=chrome-os-partner:5071
TEST=check that factory flow works on Kaen prototypes without HW fix
Change-Id: I56a830ed292d7e998fa25299f52d22d2faac3c77
Reviewed-on: http://gerrit.chromium.org/gerrit/4533
Tested-by: Luigi Semenzato <semenzato@chromium.org>
Reviewed-by: Gaurav Shah <gauravsh@chromium.org>
Reviewed-by: Luigi Semenzato <semenzato@chromium.org>
-rw-r--r-- | firmware/lib/rollback_index.c | 49 |
1 files changed, 3 insertions, 46 deletions
diff --git a/firmware/lib/rollback_index.c b/firmware/lib/rollback_index.c index a06f4858..fa9d0d03 100644 --- a/firmware/lib/rollback_index.c +++ b/firmware/lib/rollback_index.c @@ -15,10 +15,6 @@ static int g_rollback_recovery_mode = 0; -#ifdef TEGRA_SOFT_REBOOT_WORKAROUND -static int soft_reset = 0; -#endif - /* disable MSVC warning on const logical expression (as in } while(0);) */ __pragma(warning (disable: 4127)) @@ -51,21 +47,6 @@ static uint32_t SafeWrite(uint32_t index, const void* data, uint32_t length) { if (result == TPM_E_MAXNVWRITES) { RETURN_ON_FAILURE(TPMClearAndReenable()); return TlclWrite(index, data, length); -#ifdef TEGRA_SOFT_REBOOT_WORKAROUND - } else if ((result == TPM_E_BAD_PRESENCE || - result == TPM_E_AREA_LOCKED) && - soft_reset == 1) { - /* Ignore writes that failed because the TPM wasn't unlocked. - * - * This may have security implications. 1. It may delay updating the - * version number, therefore widening the window for a rollback attack. - * 2. It may prevent noticing transitions between developer mode and normal - * mode, in which case the TPM owner will not be cleared when - * transitioning. See crosbug.com/15759. Note that this code path is not - * taken on systems where a CPU reset implies a TPM reset. - */ - return TPM_SUCCESS; -#endif } else { return result; } @@ -212,11 +193,11 @@ uint32_t SetupTPM(int recovery_mode, int developer_mode, #ifdef TEGRA_SOFT_REBOOT_WORKAROUND result = TlclStartup(); if (result == TPM_E_INVALID_POSTINIT) { - /* Some prototype hardware doesn't reset the TPM on a CPU reset. We try to - * tolerate this failure, which is possible in most cases. + /* Some prototype hardware doesn't reset the TPM on a CPU reset. We do a + * hard reset to get around this. */ VBDEBUG(("TPM: soft reset detected\n", result)); - soft_reset = 1; + return TPM_E_MUST_REBOOT; } else if (result != TPM_SUCCESS) { VBDEBUG(("TPM: TlclStartup returned %08x\n", result)); return result; @@ -244,19 +225,6 @@ uint32_t SetupTPM(int recovery_mode, int developer_mode, RETURN_ON_FAILURE(TlclContinueSelfTest()); #endif result = TlclAssertPhysicalPresence(); -#ifdef TEGRA_SOFT_REBOOT_WORKAROUND - /* - * If soft_reset is true, the failure to assert PP is expected because the - * TPM is locked from a previous boot. In this case we will never execute - * the PhysicalPresenceCMDEnable below, but that's OK because this is a - * warm boot and at some point in the past we must have cold-booted with - * this firmware (one would hope), so that situation (TPM delivered with PP - * disabled) has already been resolved. - */ - if (soft_reset) { - result = TPM_SUCCESS; - } -#endif if (result != TPM_SUCCESS) { /* It is possible that the TPM was delivered with the physical presence * command disabled. This tries enabling it, then tries asserting PP @@ -484,18 +452,7 @@ uint32_t RollbackKernelLock(void) { if (g_rollback_recovery_mode) { return TPM_SUCCESS; } else { -#ifdef TEGRA_SOFT_REBOOT_WORKAROUND - TPM_STCLEAR_FLAGS flags; - uint32_t result = TlclLockPhysicalPresence(); - if (result == TPM_SUCCESS) { - return result; - } - RETURN_ON_FAILURE(TlclGetSTClearFlags(&flags)); - /* Ignore PP locking failure if PP is already locked. */ - return flags.physicalPresenceLock == 1 ? TPM_SUCCESS : result; -#else return TlclLockPhysicalPresence(); -#endif } } |