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authorDave Martin <Dave.Martin@arm.com>2020-03-16 16:50:48 +0000
committerCatalin Marinas <catalin.marinas@arm.com>2020-03-16 17:19:49 +0000
commitec94a46ee7ac999b0f10f7772c40aed3f604831b (patch)
treeb3bc62ff2f4ac7d790d2aa49351795765d86e441 /arch/arm64/kernel/process.c
parentab7876a98a2160092133de4c648e94b18bc3f139 (diff)
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arm64: BTI: Decode BYTPE bits when printing PSTATE
The current code to print PSTATE symbolically when generating backtraces etc., does not include the BYTPE field used by Branch Target Identification. So, decode BYTPE and print it too. In the interests of human-readability, print the classes of BTI matched. The symbolic notation, BYTPE (PSTATE[11:10]) and permitted classes of subsequent instruction are: -- (BTYPE=0b00): any insn jc (BTYPE=0b01): BTI jc, BTI j, BTI c, PACIxSP -c (BYTPE=0b10): BTI jc, BTI c, PACIxSP j- (BTYPE=0b11): BTI jc, BTI j Signed-off-by: Mark Brown <broonie@kernel.org> Signed-off-by: Dave Martin <Dave.Martin@arm.com> Reviewed-by: Kees Cook <keescook@chromium.org> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Diffstat (limited to 'arch/arm64/kernel/process.c')
-rw-r--r--arch/arm64/kernel/process.c17
1 files changed, 15 insertions, 2 deletions
diff --git a/arch/arm64/kernel/process.c b/arch/arm64/kernel/process.c
index b8e3faa8d406..24af13d7bde6 100644
--- a/arch/arm64/kernel/process.c
+++ b/arch/arm64/kernel/process.c
@@ -211,6 +211,15 @@ void machine_restart(char *cmd)
while (1);
}
+#define bstr(suffix, str) [PSR_BTYPE_ ## suffix >> PSR_BTYPE_SHIFT] = str
+static const char *const btypes[] = {
+ bstr(NONE, "--"),
+ bstr( JC, "jc"),
+ bstr( C, "-c"),
+ bstr( J , "j-")
+};
+#undef bstr
+
static void print_pstate(struct pt_regs *regs)
{
u64 pstate = regs->pstate;
@@ -229,7 +238,10 @@ static void print_pstate(struct pt_regs *regs)
pstate & PSR_AA32_I_BIT ? 'I' : 'i',
pstate & PSR_AA32_F_BIT ? 'F' : 'f');
} else {
- printk("pstate: %08llx (%c%c%c%c %c%c%c%c %cPAN %cUAO)\n",
+ const char *btype_str = btypes[(pstate & PSR_BTYPE_MASK) >>
+ PSR_BTYPE_SHIFT];
+
+ printk("pstate: %08llx (%c%c%c%c %c%c%c%c %cPAN %cUAO BTYPE=%s)\n",
pstate,
pstate & PSR_N_BIT ? 'N' : 'n',
pstate & PSR_Z_BIT ? 'Z' : 'z',
@@ -240,7 +252,8 @@ static void print_pstate(struct pt_regs *regs)
pstate & PSR_I_BIT ? 'I' : 'i',
pstate & PSR_F_BIT ? 'F' : 'f',
pstate & PSR_PAN_BIT ? '+' : '-',
- pstate & PSR_UAO_BIT ? '+' : '-');
+ pstate & PSR_UAO_BIT ? '+' : '-',
+ btype_str);
}
}