Message ID | 20191211154206.46260-8-broonie@kernel.org (mailing list archive) |
---|---|
State | New, archived |
Headers | show |
Series | arm64: ARMv8.5-A: Branch Target Identification support | expand |
On Wed, Dec 11, 2019 at 03:42:01PM +0000, Mark Brown wrote: > From: Dave Martin <Dave.Martin@arm.com> > > 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: Dave Martin <Dave.Martin@arm.com> > Signed-off-by: Mark Brown <broonie@kernel.org> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
diff --git a/arch/arm64/kernel/process.c b/arch/arm64/kernel/process.c index 37c508f409ac..e8eb70cd3fa0 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); } }