From 747d35bd9bb4ae6bd74b19baa5bbe32f3e0cee11 Mon Sep 17 00:00:00 2001 From: Peter Huewe Date: Wed, 30 Oct 2013 20:46:55 +0100 Subject: [PATCH] tpm/tpm_ppi: Do not compare strcmp(a,b) == -1 Depending on the implementation strcmp might return the difference between two strings not only -1,0,1 consequently if (strcmp (a,b) == -1) might lead to taking the wrong branch -> compare with < 0 instead, which in any case is more canonical. Cc: stable@vger.kernel.org Signed-off-by: Peter Huewe --- drivers/char/tpm/tpm_ppi.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/drivers/char/tpm/tpm_ppi.c b/drivers/char/tpm/tpm_ppi.c index 8e562dc65601..18c5810b646b 100644 --- a/drivers/char/tpm/tpm_ppi.c +++ b/drivers/char/tpm/tpm_ppi.c @@ -169,7 +169,7 @@ static ssize_t tpm_store_ppi_request(struct device *dev, * is updated with function index from SUBREQ to SUBREQ2 since PPI * version 1.1 */ - if (strcmp(version, "1.1") == -1) + if (strcmp(version, "1.1") < 0) params[2].integer.value = TPM_PPI_FN_SUBREQ; else params[2].integer.value = TPM_PPI_FN_SUBREQ2; @@ -179,7 +179,7 @@ static ssize_t tpm_store_ppi_request(struct device *dev, * string/package type. For PPI version 1.0 and 1.1, use buffer type * for compatibility, and use package type since 1.2 according to spec. */ - if (strcmp(version, "1.2") == -1) { + if (strcmp(version, "1.2") < 0) { params[3].type = ACPI_TYPE_BUFFER; params[3].buffer.length = sizeof(req); sscanf(buf, "%d", &req); @@ -245,7 +245,7 @@ static ssize_t tpm_show_ppi_transition_action(struct device *dev, * (e.g. Capella with PPI 1.0) need integer/string/buffer type, so for * compatibility, define params[3].type as buffer, if PPI version < 1.2 */ - if (strcmp(version, "1.2") == -1) { + if (strcmp(version, "1.2") < 0) { params[3].type = ACPI_TYPE_BUFFER; params[3].buffer.length = 0; params[3].buffer.pointer = NULL; @@ -387,7 +387,7 @@ static ssize_t show_ppi_operations(char *buf, u32 start, u32 end) kfree(output.pointer); output.length = ACPI_ALLOCATE_BUFFER; output.pointer = NULL; - if (strcmp(version, "1.2") == -1) + if (strcmp(version, "1.2") < 0) return -EPERM; params[2].integer.value = TPM_PPI_FN_GETOPR;