diff options
Diffstat (limited to 'common/recipes-kernel/linux/linux-yocto-4.9.21/0038-x86-spectre-Simplify-spectre_v2-command-line-parsing.patch')
| -rw-r--r-- | common/recipes-kernel/linux/linux-yocto-4.9.21/0038-x86-spectre-Simplify-spectre_v2-command-line-parsing.patch | 141 |
1 files changed, 141 insertions, 0 deletions
diff --git a/common/recipes-kernel/linux/linux-yocto-4.9.21/0038-x86-spectre-Simplify-spectre_v2-command-line-parsing.patch b/common/recipes-kernel/linux/linux-yocto-4.9.21/0038-x86-spectre-Simplify-spectre_v2-command-line-parsing.patch new file mode 100644 index 00000000..ad179306 --- /dev/null +++ b/common/recipes-kernel/linux/linux-yocto-4.9.21/0038-x86-spectre-Simplify-spectre_v2-command-line-parsing.patch @@ -0,0 +1,141 @@ +From 825c7a1a9545787191c7dec21823a4b854dd8172 Mon Sep 17 00:00:00 2001 +From: KarimAllah Ahmed <karahmed@amazon.de> +Date: Thu, 1 Feb 2018 11:27:21 +0000 +Subject: [PATCH 38/42] x86/spectre: Simplify spectre_v2 command line parsing + +(cherry picked from commit 9005c6834c0ffdfe46afa76656bd9276cca864f6) + +[dwmw2: Use ARRAY_SIZE] + +Signed-off-by: KarimAllah Ahmed <karahmed@amazon.de> +Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> +Signed-off-by: Thomas Gleixner <tglx@linutronix.de> +Cc: peterz@infradead.org +Cc: bp@alien8.de +Link: https://lkml.kernel.org/r/1517484441-1420-3-git-send-email-dwmw@amazon.co.uk +Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> +Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> +--- + arch/x86/kernel/cpu/bugs.c | 86 ++++++++++++++++++++++++++++++---------------- + 1 file changed, 56 insertions(+), 30 deletions(-) + +diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c +index aec7daf..957ad44 100644 +--- a/arch/x86/kernel/cpu/bugs.c ++++ b/arch/x86/kernel/cpu/bugs.c +@@ -118,13 +118,13 @@ static inline const char *spectre_v2_module_string(void) { return ""; } + static void __init spec2_print_if_insecure(const char *reason) + { + if (boot_cpu_has_bug(X86_BUG_SPECTRE_V2)) +- pr_info("%s\n", reason); ++ pr_info("%s selected on command line.\n", reason); + } + + static void __init spec2_print_if_secure(const char *reason) + { + if (!boot_cpu_has_bug(X86_BUG_SPECTRE_V2)) +- pr_info("%s\n", reason); ++ pr_info("%s selected on command line.\n", reason); + } + + static inline bool retp_compiler(void) +@@ -139,42 +139,68 @@ static inline bool match_option(const char *arg, int arglen, const char *opt) + return len == arglen && !strncmp(arg, opt, len); + } + ++static const struct { ++ const char *option; ++ enum spectre_v2_mitigation_cmd cmd; ++ bool secure; ++} mitigation_options[] = { ++ { "off", SPECTRE_V2_CMD_NONE, false }, ++ { "on", SPECTRE_V2_CMD_FORCE, true }, ++ { "retpoline", SPECTRE_V2_CMD_RETPOLINE, false }, ++ { "retpoline,amd", SPECTRE_V2_CMD_RETPOLINE_AMD, false }, ++ { "retpoline,generic", SPECTRE_V2_CMD_RETPOLINE_GENERIC, false }, ++ { "auto", SPECTRE_V2_CMD_AUTO, false }, ++}; ++ + static enum spectre_v2_mitigation_cmd __init spectre_v2_parse_cmdline(void) + { + char arg[20]; +- int ret; +- +- ret = cmdline_find_option(boot_command_line, "spectre_v2", arg, +- sizeof(arg)); +- if (ret > 0) { +- if (match_option(arg, ret, "off")) { +- goto disable; +- } else if (match_option(arg, ret, "on")) { +- spec2_print_if_secure("force enabled on command line."); +- return SPECTRE_V2_CMD_FORCE; +- } else if (match_option(arg, ret, "retpoline")) { +- spec2_print_if_insecure("retpoline selected on command line."); +- return SPECTRE_V2_CMD_RETPOLINE; +- } else if (match_option(arg, ret, "retpoline,amd")) { +- if (boot_cpu_data.x86_vendor != X86_VENDOR_AMD) { +- pr_err("retpoline,amd selected but CPU is not AMD. Switching to AUTO select\n"); +- return SPECTRE_V2_CMD_AUTO; +- } +- spec2_print_if_insecure("AMD retpoline selected on command line."); +- return SPECTRE_V2_CMD_RETPOLINE_AMD; +- } else if (match_option(arg, ret, "retpoline,generic")) { +- spec2_print_if_insecure("generic retpoline selected on command line."); +- return SPECTRE_V2_CMD_RETPOLINE_GENERIC; +- } else if (match_option(arg, ret, "auto")) { ++ int ret, i; ++ enum spectre_v2_mitigation_cmd cmd = SPECTRE_V2_CMD_AUTO; ++ ++ if (cmdline_find_option_bool(boot_command_line, "nospectre_v2")) ++ return SPECTRE_V2_CMD_NONE; ++ else { ++ ret = cmdline_find_option(boot_command_line, "spectre_v2", arg, ++ sizeof(arg)); ++ if (ret < 0) ++ return SPECTRE_V2_CMD_AUTO; ++ ++ for (i = 0; i < ARRAY_SIZE(mitigation_options); i++) { ++ if (!match_option(arg, ret, mitigation_options[i].option)) ++ continue; ++ cmd = mitigation_options[i].cmd; ++ break; ++ } ++ ++ if (i >= ARRAY_SIZE(mitigation_options)) { ++ pr_err("unknown option (%s). Switching to AUTO select\n", ++ mitigation_options[i].option); + return SPECTRE_V2_CMD_AUTO; + } + } + +- if (!cmdline_find_option_bool(boot_command_line, "nospectre_v2")) ++ if ((cmd == SPECTRE_V2_CMD_RETPOLINE || ++ cmd == SPECTRE_V2_CMD_RETPOLINE_AMD || ++ cmd == SPECTRE_V2_CMD_RETPOLINE_GENERIC) && ++ !IS_ENABLED(CONFIG_RETPOLINE)) { ++ pr_err("%s selected but not compiled in. Switching to AUTO select\n", ++ mitigation_options[i].option); + return SPECTRE_V2_CMD_AUTO; +-disable: +- spec2_print_if_insecure("disabled on command line."); +- return SPECTRE_V2_CMD_NONE; ++ } ++ ++ if (cmd == SPECTRE_V2_CMD_RETPOLINE_AMD && ++ boot_cpu_data.x86_vendor != X86_VENDOR_AMD) { ++ pr_err("retpoline,amd selected but CPU is not AMD. Switching to AUTO select\n"); ++ return SPECTRE_V2_CMD_AUTO; ++ } ++ ++ if (mitigation_options[i].secure) ++ spec2_print_if_secure(mitigation_options[i].option); ++ else ++ spec2_print_if_insecure(mitigation_options[i].option); ++ ++ return cmd; + } + + /* Check for Skylake-like CPUs (for RSB handling) */ +-- +2.7.4 + |