From c8c0da6bdf0f0d6f59fc23aab6ee373a131df82d Mon Sep 17 00:00:00 2001 From: Paul Burton Date: Wed, 24 Sep 2014 10:45:37 +0100 Subject: MIPS: Fix MFC1 & MFHC1 emulation for 64-bit MIPS systems Commit bbd426f542cb "MIPS: Simplify FP context access" modified the SIFROMREG & SIFROMHREG macros such that they return unsigned rather than signed 32b integers. I had believed that to be fine, but inadvertently missed the MFC1 & MFHC1 cases which write to a struct pt_regs regs element. On MIPS32 this is fine, but on 64 bit those saved regs' fields are 64 bit wide. Using unsigned values caused the 32 bit value from the FP register to be zero rather than sign extended as the architecture specifies, causing incorrect emulation of the MFC1 & MFHc1 instructions. Fix by reintroducing the casts to signed integers, and therefore the sign extension. Signed-off-by: Paul Burton Cc: stable@vger.kernel.org # v3.15+ Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/7848/ Signed-off-by: Ralf Baechle --- arch/mips/math-emu/cp1emu.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'arch/mips') diff --git a/arch/mips/math-emu/cp1emu.c b/arch/mips/math-emu/cp1emu.c index bf0fc6b16ad9..7a4727795a70 100644 --- a/arch/mips/math-emu/cp1emu.c +++ b/arch/mips/math-emu/cp1emu.c @@ -650,9 +650,9 @@ static inline int cop1_64bit(struct pt_regs *xcp) #define SIFROMREG(si, x) \ do { \ if (cop1_64bit(xcp)) \ - (si) = get_fpr32(&ctx->fpr[x], 0); \ + (si) = (int)get_fpr32(&ctx->fpr[x], 0); \ else \ - (si) = get_fpr32(&ctx->fpr[(x) & ~1], (x) & 1); \ + (si) = (int)get_fpr32(&ctx->fpr[(x) & ~1], (x) & 1); \ } while (0) #define SITOREG(si, x) \ @@ -667,7 +667,7 @@ do { \ } \ } while (0) -#define SIFROMHREG(si, x) ((si) = get_fpr32(&ctx->fpr[x], 1)) +#define SIFROMHREG(si, x) ((si) = (int)get_fpr32(&ctx->fpr[x], 1)) #define SITOHREG(si, x) \ do { \ -- cgit v1.2.3 From 8a574cfa2652545eb95595d38ac2a0bb501af0ae Mon Sep 17 00:00:00 2001 From: Markos Chandras Date: Tue, 16 Sep 2014 15:55:12 +0100 Subject: MIPS: mcount: Adjust stack pointer for static trace in MIPS32 Every mcount() call in the MIPS 32-bit kernel is done as follows: [...] move at, ra jal _mcount addiu sp, sp, -8 [...] but upon returning from the mcount() function, the stack pointer is not adjusted properly. This is explained in details in 58b69401c797 (MIPS: Function tracer: Fix broken function tracing). Commit ad8c396936e3 ("MIPS: Unbreak function tracer for 64-bit kernel.) fixed the stack manipulation for 64-bit but it didn't fix it completely for MIPS32. Signed-off-by: Markos Chandras Cc: Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/7792/ Signed-off-by: Ralf Baechle --- arch/mips/kernel/mcount.S | 12 ++++++++++++ 1 file changed, 12 insertions(+) (limited to 'arch/mips') diff --git a/arch/mips/kernel/mcount.S b/arch/mips/kernel/mcount.S index 5d25462de8a6..2f7c734771f4 100644 --- a/arch/mips/kernel/mcount.S +++ b/arch/mips/kernel/mcount.S @@ -129,7 +129,11 @@ NESTED(_mcount, PT_SIZE, ra) nop #endif b ftrace_stub +#ifdef CONFIG_32BIT + addiu sp, sp, 8 +#else nop +#endif static_trace: MCOUNT_SAVE_REGS @@ -139,6 +143,9 @@ static_trace: move a1, AT /* arg2: parent's return address */ MCOUNT_RESTORE_REGS +#ifdef CONFIG_32BIT + addiu sp, sp, 8 +#endif .globl ftrace_stub ftrace_stub: RETURN_BACK @@ -183,6 +190,11 @@ NESTED(ftrace_graph_caller, PT_SIZE, ra) jal prepare_ftrace_return nop MCOUNT_RESTORE_REGS +#ifndef CONFIG_DYNAMIC_FTRACE +#ifdef CONFIG_32BIT + addiu sp, sp, 8 +#endif +#endif RETURN_BACK END(ftrace_graph_caller) -- cgit v1.2.3